Fish Cultivation in Confined Land

Fish Cultivation in Confined Land

With the new method, carp can now be grown in a narrow area, such as in the yard or the corner, home.

The notion that the cultivation of carp to be done in the vast wetland is now living myth.

Today carp can be cultivated in any location, whether in rural or urban, in the pool tarp, plastic or tub.

That way, carp can be an alternative to people who want to earn extra income on the land around their homes.

Fisheries Society Archipelago (PERMINA) Cultivation Training will hold a carp on a narrow land-based Guba biotic System Based Probiotic on Sunday, March 6, 2011 in Kampung carp Jambida, Bantul. Yogyakarta, With a practical resource, Kalimantan, Java carp tissue holder, carp farmers, and agribusiness consultant.

Besides the introduction to the basics of carp cultivation correctly, in Gubug PERMINA Training is focused on direct practice in the pool, good pond, nesting, breeding and rearing, so they can run interactive and applicable.

Training is open to the public, may be followed by anyone, retirees, employees, housewives, youth clubs, preachers, teachers and scholars of rural driving

SOURCE: MEDIA INDONESIA 18 FEBRUARY 2011 PAGE 20

Argulosis (fish disease)

Argulosis (fish disease)


Cause: Argulus sp.
Bio-Ecology Pathogens:
• The parasite is known as "fish lice" and sucking blood, is flat. and more looks like a plate.
• Hurt fish body with the help of cytolytic enzymes, in addition to the skin, ticks are also frequently found in fish gills under the cap.
• Almost all freshwater fish species susceptible to this parasite infection.
• In high-intensity attacks. Adult fish can suffer death from lack of blood.

Clinical Symptoms:
• Visually it looks like a flea parasites that attach to the body of the fish. accompanied by bleeding around the bite.
• skin irritation, loss of balance, swimming in a zig-zag, jump into the water and rubbed his body on hard objects around him.


Diagnosis:
• Visually looks a parasite that attach to the fish body


Control:
• Draining of the pond, followed by calcification.
• Soaking can be done by:
✓ Dylox solution at doses of 0.25 ppm for 24 hours or more in the pool.
✓ solution of Ammonium chloride (NH4CI) at a dose of 1.0 -1.5% for 15 minutes, or table salt at doses of 1.25% for 15 minutes.
✓ dichlorvos solution 0.2 mg / L for 24 hours or more, every week for 4 consecutive weeks
✓ kitchen Salt 500 - 1000 ppm for 24 hours or more, repeated every week for 4 times giving
✓ Potassium permanganate (PK) 2-5 mg / L for 24 hours or more.

source: Ministry of Maritime Affairs and Fisheries of Indonesia, Directorate General of Aquaculture, Fish and Environmental Health Directorate, 2010

Worms In Fish Gills

Worms In Fish Gills
Cause: Haliotrema spp., Psedorhabdosynochus spp.
Bio-Ecology Pathogens:
• Ekto-parasites are obligate parasitic
• infect the gills of fish mariculture. Two or possibly three species belong to the genus monogenea Pseudorhabdosynochus namely Pseudorhabdosynochus latesi. P. monosquamodiscusi, and Diplectanum penangi, while P. epinepheli found in groups of grouper.

Clinical Symptoms:
• pale body color, decreased appetite, lean, and slow
• Respiratory frequency increased and the production of excess mucus in the gills
• Gather / closer to the water inlet
• Gills pale or swollen so that the open operculum

Diagnosis:
• Visual observation of behavior and clinical symptoms that arise
• Microscopic observation to see morphology
parasites through the production segment of the organ gill preparations.

Control:
• Reducing the levels of dissolved organic material and / or increase the frequency of water changes
• worm attacked fish gill with the level and intensity of the low prevalence, treatment can be done by soaking in a solution of formalin at doses of 25-50 ppm for 24 hours or more.

source : Kementerian Kelautan dan Perikanan, Direktorat Jenderal Perikanan Budidaya, Direktorat Kesehatan Ikan dan Lingkungan, 2010

Dactylogyriasis (Worms Gills)

Dactylogyriasis (Worms Gills)

Cause: Dactylogyrus spp., Cychlidogyrus spp., Quadricanthus spp.

Bio-Ecology Pathogens

• Ekto-obligate parasites that are parasitic and reproduce by laying eggs
• infect all species of freshwater fish, especially the size of the seed. Transmission occurs when infective face (Onchomiracidium).
• Dactylogyrus spp. has 2 pairs of eye point, and at the tip of his head there are 4 bumps. Cychlidogyrus spp. shape is more flattened at both ends, and only has a pair of eye point. Quadricanthus spp. shape
Dactylogyrus similar spp., and has a host of species that target specific groups of catfish.
• Severe infections can kill 30-100% within a few weeks

Clinical Symptoms:
• pale body color, decreased appetite, thin, nervous and slow
• Respiratory frequency increased, the production of excess mucus in the gills and often cavort
• Gather / closer to the water inlet
• Gills pale or swollen so that the open operculum

Diagnosis:
• Visual observation of behavior and clinical symptoms that arise
• Microscopic observation to see morphology
parasites through the production segment of the organ gill preparations.

Control:
• Maintaining water quality, especially the stabilization of the water temperature> 29 degrees Celsius
• Reducing the levels of dissolved organic material and / or increase the frequency of water changes
• Dactylogyriasis attacked fish with prevalence and intensity level is low, treatment can be done by soaking several types of disinfectants, among others:
✓ salt solution at a concentration 500-10000
ppm (depending on the type and age of fish) for 24 hours
✓ Solution Potassium Permanganate (PK) at a dose of 4 ppm for 12 hours
✓ formalin solution at doses of 25-50 ppm for 24 hours or more
✓ Glacial acetic acid 0.5 ml / L for 30 seconds every 2 days for 3 - 4 times

source: Ministry of Maritime Affairs and Fisheries of Indonesia, Directorate General of Aquaculture, Fish and Environmental Health Directorate, 2010

Microsporidiasis (Cotton Shrimp Disease)

Microsporidiasis (Cotton Shrimp Disease)

Cause: The Microsporidia of the genera Thelohania, Nosema and Peistophora

Bio - Ecology Pathogens
• Named as cotton shrimp disease and / or shrimp milk.
• Having more than 8 spores in each capsule
• Virtually all penaeid shrimp species was reported the least susceptible to infection one type of parasite microsporidia group, although there are indications of specific local

• low pathogenicity, prevalence rates in a population generally not more than 5% and the resulting mortality was also relatively low


Clinical symptoms:
• Parts of the body of infected shrimp white milk and more soft
• white spores spread on the meat / muscle (internal parasites)
• Shrimp weak, easy to stress, decreased appetite, making it easy prey to predators sluggish, and easily die after handling (handling)

Diagnosis:
• Visual observation of behavior and clinical symptoms are quite clear
• Microscopic observation to see the morphology of microsporidia by making preparations for review of target organ infection. The observation that more clear on the characteristics of spores required specific staining.

Control:
• disinfection, drying of pond bottom and water sources that are free of microsporidia
• Shrimp are infected immediately destroyed, in order to reduce the potential for horizontal transmission
• To cut the parasite's life cycle, avoiding the feeding of trash fish infected with microsporidia
• No chemicals are effective for preventing and / or treat diseases microsporidiasis.

source: Ministry of Maritime Affairs and Fisheries Republic of Indonesia, Director General. Aquaculture, 2010

FISH FOR HEALTH BENEFITS

FISH FOR HEALTH BENEFITS
Source: September 2009 Edition WartaPasar Fish, No. 73


Benefits of eating fish regularly can reduce a variety of diseases, among others:
1. ASTHMA
Children who eat fish will decrease the risk of suffering from asthma.

2. EYE
Fish rich in omega-3 fatty acids that can contribute to the health of brain tissue and retina of the eye. Breastfed babies of mothers who eat fish have better eyesight caused by omega -3 fatty acids transmitted in breast milk.

3. HEART & STROKE
Eating fish every week reduces the risk of heart disease and stroke by reducing blood clotting and inflammation, improving blood vessel elasticity, lowering blood fats and increase good cholesterol. Hundreds of studies have been done on fish or fish oil and its role in the prevention or treatment of heart disease. Reviews contained dakam British Medical Journal recommends fish or taking fish oil supplements to prevent heart attacks, especially in people with vascular disease. Omega-3 is known to lower blood triglycerides and blood pressure, prevent clotting, anti-inflamsai and correct abnormal heart rtme.

4. Dementia
Parents who eat fish or seafood at least once a week had a lower risk of development of dementia including Alzheimer's disease.

5. DIABETES
Eating fish may help regulate blood sugar levels in diabetics.

6. RHEMATOID
Regular fish consumption can alleviate symptoms of rheumatoid arthritis, psoriasis and autoimmune diseases.

7. Born prematurely
Eating fish during pregnancy may reduce the risk of premature delivery.

Koi Care: How to Take Care of Your Aquatic Pet

Koi Care: How to Take Care of Your Aquatic Pet

by: Andy Fletcher

When you decide to keep Koi fish as pets, you must learn a few very basic and vital things about Koi care. Proper nutrition and water quality are the two deciding factors that you have to look at while thinking about Koi care.

Koi fishes are hardy specimens of fish and they can live for long periods of time, sometimes for more than 200 years though the average life span is around 25 to 35 years. These Koi fishes are easy going hassle free kinds of pets and don’t give much trouble to their keepers and you will find it easy to take care of them.

Koi Care – Pond Water Quality

One of the most critical conditions of Koi care is perhaps the quality of the water in the pond. You would be surprised to know that Koi needs fresh and good quality water for their habitat more than food. A Koi will not starve to death if it doesn’t receive food for several weeks, however, it can die in one night if the water quality turns out to be very poor.

You always have to pay attention to how you will sustain your pond water quality through proper filtration and supplies and you also have to chalk out or fix a budget for your pond water quality maintenance expenses.

Nutrition

Another thing to keep in mind is Koi nutrition and proper nutrition will ensure that the kois can protect themselves from diseases, they will grow up to the right proportion and size and you don’t have to worry about good body conformation.

Nursing

One more thing that you should remember about Koi care is that you need to react promptly and take necessary precautionary steps or measures of redressal to combat Koi health problems and accidents. That means if the need arises, you have to even apply first aid to a sick or injured Koi or administer the correct medication.

You also have to take into account the seasonal care pattern for Koi fish. For e.g. in the spring months, Koi fishes feel their worst while summer happens to be their best season for grow out. The Koi fish usually spends the fall months preparing for the harsh cold weather of winter by generating enzymes.

And during winter months, the Koi fishes go deep into sleep or hibernation. Thus it is clear that Koi fishes require separate types of care and maintenance during the various seasons of the year.

Predators

While on the topic of Koi care, I must inform you about potential predators that can feast on your pet Koi. You have to guard your fish from raccoons for these masked and dark circled bandits have been observed to be the most common predators, if you are really serious about Koi care.

About The Author

Learn everything you ever wanted to know about Koi Care

Visit the author's web site at:

http://www.koicareandsupplies.com

3 Great Fish For Your Tropical Aquarium

3 Great Fish For Your Tropical Aquarium

by: Paul Curran

Lamp Eye, Madagascar Rainbow Fish and the Medaka are three fish suitable for your tropical aquarium. Find out about their behavior, what they look like, water conditions, how to feed them and how to breed them

Lamp Eye - Aplocheilichthys macrophthalmus (Family: Cyprinodontidae)

As this fish rarely grows to more than 3 cms you need to assess your community aquarium to see if there are any of the others that lean towards the aggressive and might harm them. For their size these fishes eyes are bigger than you might expect and show as a greenish gold in low light; hence the common names, Lamp or Lantern eye.

As an active fish with a good leap, you must have a cover on the tank to stop them jumping out and the use of floating plants will help. For these fish to enjoy their stay, matured aquarium water is required at a temperature of between twenty three and twenty six degrees Celcius.

Shape wise, the fish has a long body, thinner at the front with a mouth that points upwards slightly. It has attractive fins on a gray green body which may have a dark line along the back with a spotted shiny thin band along the flank. The male's ventral and dorsal fins are more pointed than the female.

Breeding wise, eggs are either laid individually or in bunches that end up amongst the plants. Once laid it is best practice to remove the parents. The eggs will hatch in about a week and a half and you will have to be very careful with the fry as they are a bit delicate.

Madagascar Rainbow Fish - Bedotia geayi (Family: Atherinidae)

Keeping this fish in a shoal (not large) with water between 25 and 18 degrees centigrade will see them at their best in your community tank. It is an active swimmer and sturdy little fish that grows up to about 8 cms and likes to dwell in the top part of the aquarium. Although it has only come onto the scene a relatively short time ago this fish has become a favorite with aquarium lovers.

Body wise, it has a somewhat unique feature in that it has two dorsal fins, a short one and a long one. Color wise, the main color is olive green and there is a stripe along the sides of the fish from eye to tail. It is easy to feed as it it accepts most offerings so ideally give it a varied diet.

Breeding is easy for this species so you need to have thickly planted tank with hard water at a temperature of at least 26 degrees centigrade. Eggs laid will adhere to plants and the eggs themselves are quite big but you will have to wait a few days for completion as only a few eggs are laid per day. Bear in mind that due to the extended spawning period, fry will hatch and be at various stages of their development.

Medaka - Oryzias latipes (Family: Oryziatidae)

This fish is ideal for your tropical aquarium. It grows to about 5 cms, will consume most foods and can survive in a wide range of temperatures, although 20 to 24 degrees centigrade is the best for it. There are three other species of Oryzias that you may also come across under the name medaka but the Oryzias latipes is the main one.

With this fish there are no specific patterns on its mainly gold color. Its head is slimmer than you would normally expect and its body lengthier than usual. It is interesting to know that before breeding took place the original color was; well there wasn't one. It was transparent!

Males are somewhat smaller than females and have bigger fins. Breeding is relatively easy and the tank should be at the same temperature as the main tank, have floating plants and be thickly planted underwater with fine leaved plants. Until they have been fertilized, the eggs will stay attached to the end of the female.

It is best practice to take out all the plants with attached eggs from the tank to another one and after about two weeks the fry will emerge. Remove and feed on infusoria then fine dry food, then micro worms and other food for the more grown up fish.

So there you have it, three more excellent fish for your tropical aquarium collection.

About The Author

Paul Curran is webmaster at Fresh-Water-Aquariums-Guide.com and provides a care information system for fresh water aquariums at http://www.fresh-water-aquariums-guide.com/fsa-sales.html

The author invites you to visit:

http://Fresh-Water-Aquariums-Guide.com

prospective parent tilapia

Prospective Parent Nila

female tilapia

male tilapia






- Board of brightly colored grayish black

- Form of lamellar body (compressed) with full and regular scale

- Member or incomplete organs, scales regularly, your body is not disabled and there is no deformity, the body is not attached by a parasite, no lumps, gill net, gill cover normal (not thick or thin) and slimy.

- * Elasticity body: chewy and not mushy

- Age:

Males 6-8 months

Females 6-8 months

- Total length:

Males 16-25 cm

Females 14-20 cm

- Body weight:

Males: 400-600 grams

Females: 300-450 grams

Betta Fish Is The Perfect Pet Fish

Betta Fish Is The Perfect Pet Fish
by: Rosalinda Zamora


I still remember the first time I saw two beautiful looking fish in a friend's house. One fish was blue and the other was red, and they were swimming majestically in their fishbowls. That was my first encounter with a fish species known as Betta fish or Betta Splendens or Siamese Fighting Fish (three names that refer to one fish).

Up until today, I'm still keeping a few of them in my house, and they make perfect pet fish for my family. Every member of my family loves them.

Why do I like most about Betta fish, you may ask. Definitely, I have many different reasons, but here are three of them.

1. Betta fish are beautiful pet.

It's a tropical fish that comes with different colors such as red, blue and yellow. Some Betta fish have more than one color on their bodies. Believe it or not! I can spend hours looking at how Betta fish move in their bowls but even if you don't know a thing about Betta fish, you will be mesmerized by their colors alone.

2. Betta fish are easy to care.

Betta fish are hardy type of fish and they can live in a small container. A small fishbowl is enough to house one Betta fish, but be aware that two male Betta fish shouldn't be placed in one container. Or else, these two Betta fish might fight until death (that's why they are also called Siamese fighting fish).

3. Betta fish are responsive.

If you have a Betta fish in a small fishbowl and you move closer to the fish, you'll see that your fish will turn its head to look at you. That's what makes me fall in love with Betta fish. They are responsive to your presence and aware that you are there, unlike many other pet fish.

So, you can now consider if you want to adopt Betta fish as your family pet or for your kids. They are lovable creatures and you will know it immediately one you have a Betta in your house.

About The Author
Rosalinda Zamora is a betta fish lover. To get FREE info about caring for betta fish, go to http://www.BettaFishSecret.com and she'll surprise you with more awesome articles from betta fish experts.

measuring fecundity with fish length

population fecundity relative from one hundred, a thousand or ten thousand individual of certain age group. Amount of fish in every age class multiplied [by] mean fecundity of that age. Result of which [is] got from suming all age group give fecundity relative. this fecundity can differ from year to year because many individual which is not prolific annually. If in one year, there are individual in number many will cause low fecundity in the year the other.

fecundity with length.
fecundity [is] often attributed to length than weighing, because its decrease length [of] infinitesimal relatip [do] not like weight able to decrease easily. Matter which must be paid attention in making [relation/link] of fecundity with length if taking sampel which repeatedly have to take a care, because if taken fish when gonad [is] growing this matter [do] not represent growth of somatik. Become here difference there must be [among/between] growth of somatik with growth of gonad. Most [all] writer plot absolute fecundity with fish length and that [relation/link] [is]:

Where
F = fecundity,
L = long [of] fish,
and a of b represent got konstanta of data.
The equation if [is] likened into to logarithm will get equation of straight line regresi

Log F = log a + b log L


Price Exponent of b range from 2,34 - 5,28 and most gyrating above 3 ( Bagenal, in Gerking, 1967). There [is] also making Correlation [among/between] fecundity with length by ordinary regresi later;then dites seen its correlation coefficient. Hoyt ( 1971) getting equation for the length of fish with amount of ripe egg of fish of silver jaw ( Bucata Ericymba) that is

Y = (- 1379,3 + 32,74 X )

with correlation coefficient of r = 0,89.



This correlation show strong and positive [relation/link] from both variable. Additional [of] length have correlation [to] with accretion of egg. Healy ( 1971) getting linear correlation almost [among/between] fecundity with fish length of sand goby ( Minutes pallas Gobius), but variation [of] among fish Which [is] of uniform length, fecundity different each other and its correlation coefficient lower that is r = 0,55. In investigating fish of fall fish ( Corporalis Semotilus), Reed ( 1971) getting [relation/link] [among/between] fecundity with fish length [is].


F = - 14.913,3 + 76,7 L

with correlation coefficient of r = 0,958.

Dennison and of Bulkley ( 1972) during twice accurate summer [of] potency reproduce fish of bullhead ( Ictalurus braze) [in] Clear Lake Iowa, for example getting that [there] no correlation [among/between] fecundity with body length ( Picture 7). Correlation coefficient got for year 1969, r = 0,19 and for year 1970, r = 0,09. Lowering of got correlation possible because of extreme rotation boundary of fecundity [at] [is] same size measure represent matter which [do] not habit. Batts ( 1972) getting low r [at] fish of skipjack poor (Katsuwonus Pelamis ), showing fecundity which vary [at] [is] same footage.

footage. sumber. M. Ichsan Effendie

Carp Fish Transportation Equipment

Carp Fish Transportation Equipment

Transportation equipment, this carp is in the form of plastic jerry cans which the sides are opened. freight containers used to transport these fish carp size 5-12 cm.

transport of carp using plastic jerry cans are very practical and easily operationalized. When used for transportation, containers usually do not use one or two pieces but a lot can be 10-20 units.

Cultured Grass Carp

Information on the culture of the grass carp (Ctenopharyngodon idellus Valenciennes) from the FAO Cultured Aquatic Species Information Programme.

Identity

Biological features

Body elongated and cylindrical, round abdomen, compressed at the rear; standard length is 3.6-4.3 times of body height and 3.8-4.4 times of head length; length of caudal peduncle is larger than the width; head medium; terminal mouth and arch-shaped; upper jaw extends slightly over lower jaw, its rear can reach below eye; snout width is 1.8 times of the length, snout length is about the nasal distance; no palpus; gill rakes short and sparse (15-19); two rows of pharyngeal teeth on each side, laterally compressed, formula 2.5-4.2, inner row stronger, grooves on the lateral surface; scales large and cycloid; extreme 39-46 scales in lateral line, lateral line extends to caudal peduncle. Anus close to anal fin; Dorsal fin ray: 3,7; pectoral fin ray: 1,16; ventral fin ray: 1,8; anal fin ray: 3,8; caudal fin with around 24 rays; body color: greenish yellow laterally, dorsal portion dark brown; greyish white in abdomen.

Profile

Historical background

Grass carp culture began in the areas along the Yangtze and Pearl Rivers in the southern part of China. Compared to common carp, the culture of grass carp started much later. According to historical records, the culture of grass carp was closely related to the will of the current governor.

In the Tang Dynasty (618-904 A.D.), the family name of the emperor happened to be pronounced the same in Chinese as common carp, the only fish cultured then. The royal family prohibited common carp to be sold and killed by the people. Therefore, grass carp was chosen by the farmers as a substitute for aquaculture together with silver carp, bighead and black carp; this was because the seed of these fish were easily available in the areas along the Yangtze River and the Pearl River.

The culture of grass carp remained relatively small in scale due to the dependence on the natural supply of seed. Success in induced breeding technology significantly promoted its culture. The fish has been introduced to more than 40 other countries; sometimes it is referred to as the white amur.

About 10 000 tonnes/yr in 1950, the global production of farmed grass carp had reached over 100 000 tonnes/yr by 1972, exceeded 1 million tonnes/yr by 1990, and has been above 3 million tonnes/yr since 1999. China is by far the major producer (3 419 593 tonnes in 2002, 95.7 per cent of the global total).

Main producer countries

In 2006, many countries reported cultured production of grass carp to FAO but only some of them (Bangladesh, China, Taiwan Province of China, Islamic Republic of Iran, the Lao People's Democratic Republic, Myanmar and Russian Federation) reported a production greater than 1 000 tonnes.

Habitat and biology

Grass carp is a native Chinese freshwater fish with a broad distribution from the catchment area of the Pearl River in southern China to that of the Heilongjiang River in northern China. It has been introduced to about 40 other countries and there have been limited reports about the natural populations occurring in those areas; for instance, a natural population exists in the Red River in Vietnam.

It inhabits lakes, rivers and reservoirs. It is a basically herbivorous fish that naturally feeds on certain aquatic weeds. However, the fry/larvae feed on zooplankton. Under culture conditions, grass carp can well accept artificial feed such as the by-products from grain processing, vegetable oil extraction meals, and pelleted feeds, in addition to aquatic weeds and terrestrial grasses. Grass carp normally dwell in mid-lower layer of the water column. Comparatively, it prefers clear water and can move swiftly.

It is a semi-migratory fish; the mature broodstock migrate to the upper reaches of major rivers to propagate. Flowing water and changes in water level are essential environmental stimuli for natural spawning. The fish can reach sexual maturity under culture conditions, but cannot spawn naturally. Hormone injection and environmental stimuli, such as flowing water are necessary for induced spawning in tanks. Gras carp grow rapidly and reach a maximum weight of 35 kg in the wild.

Production

production systems

Various production systems are currently used for the culture of grass carp the major ones include semi-intensive and intensive culture ponds, and pens and cages in open waters.

Seed supplu

At present artificial propagation is the major supply of seed for the culture of grass carp, although natural seeds are still available in some rivers of China. Seed collected from the wild is mainly used for maintaining the genetic quality of the broodstock. Broodstocks used for artificial propagation are usually raised in captivity from seeds from the wild or from breeding stations where good natural stocks are maintained.

Hatchery production

Well-matured breeders are released into the spawning tank (round cement tank with diameter of 6-10 m and water depth of around 2 m) after being injected with inducing hormone (usually LRH-A). Water circulation is maintained throughout the spawning period.

Eggs are transferred to hatching raceways or jars, either manually or by gravity. Hatching raceways (which are round or ellipse-shaped structures) are commonly used for large-scale production. The width of the raceways is normally 0.8 m and the depth is 0.8-1.0 m. The inlets are mounted on the bottom of the raceways with openings in the same direction and at an angle of around 15° to the bottom, to promote water circulation. Screens are mounted on the inner wall for discharging water during the operation. Water can be totally drained out through the outlet on the bottom. Current flow is maintained during the hatching period to keep the eggs and larvae suspended in the water column.

In India, dry or wet stripping methods are used for the seed production of grass carp. Pituitary extract or synthetic agents such as ovaprim are used for induction (John Stephen Kumar, pers. comm. 2004).

Nursery

Earthen ponds (usually 0.1-0.2 ha and 1.5-2.0 m deep) are used for the nursing of grass carp. Ponds are chemically cleared, normally with quicklime, to eliminate all harmful organisms after totally drying. The usual dose is 900-1 125 kg/ha.

Organic fertiliser, animal manure and/or plant wastes (‘green manure‘) is commonly applied to increase the natural biomass of algae and zooplankton 5-10 days before the stocking, according to the water temperature. The quantity of organic fertiliser used is usually 3 000 kg/ha for animal manure or 4500 kg/ha for green manure. Green and animal manures can be used simultaneously but the quantity of each should be reduced accordingly.

Monoculture is practiced in the nursery stage, with a stocking density normally ranging between 1.2-1.5 million/ha, depending on the length of rearing and targeted size. The nursery operation usually takes 2-3 weeks in China.

Organic fertilisation is carried out at frequencies and rates sufficient to maintain high pond fertility and therefore a good supply of natural food organisms (especially zooplankton) for the fish. The quantity ranges from 1 500-3 000 kg/ha once every 4-5 days for animal manure or green manure, depending on existing water fertility.

Soybean milk can also be used as both direct feed and fertiliser to replace organic fertiliser in the nursery stage. The normal quantity is 3-5 kg (dry soybean)/100 000 fish daily. This usually means production costs are high. A paste-form of soybean cake or other by-products from grain processing is applied from the 5th day after stocking, usually at a rate of 1.5-2.5 kg/100 000 fish daily.

A paste of water peanut, water lettuce and water hyacinth can also be used to replace the above-mentioned feed and fertilisers at the rate of 25-40 kg/100 000 fish daily. 0.5 per cent of table salt needs to be added to the paste of water peanut to remove its saponin toxicity. Normal survival rates in nursery ponds are 70-80 per cent, although it may reach over 90 per cent under good management.

The fish usually reach the size of about 30 mm in length after 2-3 weeks of rearing. These are called summer-fingerlings in China and are ready for the fingerling rearing stage. Conditioning, through careful netting and holding the fish at high density for a while (several hours) is required before the transfer of summer-fingerlings to the fingerling pond. This practice is designed to fish tolerance to stress before they are transported.

Rearing fingerlings

Summer-fingerlings are not suitable for direct stocking in grow-out ponds; they need to be reared to the fingerling stage (13-15 cm in length or larger) first. The technique for fingerling rearing is rather different to the nursery operation, especially when grass carp are stocked as the major species. The major differences include the following:

• Relatively larger (0.2-0.3 ha) and deeper earthen ponds are used for fingerling rearing.
  
  
• Contrary to the nursery stage, polyculture is usually adopted for the production of grass carp fingerlings (monoculture at this stage is quite rare). Grass carp can be polycultured with other carp species except black carp (Mylopharyngodon piceus).
  
  
• The stocking density is 120 000-150 000/ha when it is the major species in the pond or 30 000/ha when it is the secondary species.
  
  
• Feeding is vitally important throughout the fingerling rearing period. Grass carp are mainly fed with Wolffia arrhiza when it is between 30-70 mm in length. The initial feeding rate is 10-15 kg/10 000 fish daily and is gradually increased according to the demand of the fish. The feed is changed to duckweed (Lemna minor) when the fish is between 70-100 mm in length. After that, the fish can be fed with tender aquatic weeds and terrestrial grasses. In addition, commercial feeds (soybean cake, rapeseed cake, wheat bran, rice bran, etc.) are also fed at a daily rate of 1.5-2.5 kg/10 000 fish.
  
  
• Fingerling rearing normally takes 4-6 months for above mentioned size and stocking density in China. The period can be considerably shortened in warmer climates or if lower stocking densities are used.
  
  
• The normal survival rate through the whole fingerling rearing period should be above 95 per cent.

It is difficult to culture grass carp from the yearling size (13-15 cm) to marketable size (>1 500 g) within one year in most parts of China; it is therefore common practice to rear yearlings to 2 year old fingerlings for grow-out stocking. The stocking density is much reduced, compared to the rearing of yearlings. The feeding regime is similar but the rate is much higher. By the end of this period, the fish have usually reached about 250 g. This practice is not necessary in tropical and subtropical areas, where yearlings of grass carp can reach marketable size within one year, due to high temperatures.

In Vietnam, the rearing of grass carp before the grow-out stage is divided into two periods. Fry are first raised to 4-5 cm, with a stocking density in the earthen nursery pond of 200-250 fry/m². The rearing period is normally 1.5-2 months. Then the fish are further raised for about 2 months to a size of 12-15 cm at a much lower density. The fish is mainly fed with soybean powder, rice bran, maize powder and aquatic plants (Azolla sp.) after reaching 3 cm in body length.

The nursery rearing of grass carp in India is carried out in intensively fertilised ponds, adequately enriched with zooplankton and unicellular algae. Generally the survival of fry is about 70-80 per cent in well-managed nursery ponds. In addition to the natural feeds developed, supplementary feeding with powdered groundnut oilcake and rice polishings or bran is also practiced (John Stephen Kumar, pers. comm. 2004).

Ongrowing techniques

The most commonly adopted ongrowing techniques for grass carp include polyculture in ponds and pen and cage culture in lakes and reservoirs.

Semi-intensive to intensive polyculture in ponds in China

For polyculture in ponds or pens, grass carp can be stocked either as the major species or a secondary species together with other carp species. The total stocking density is 750-3 000 fish/ha with a stocking size of 125-250 g. Aquatic weeds and terrestrial grasses form the major feed for grass carp in grow-out culture. Feeding commercial feeds such as pellets and by-products from vegetable oil extraction and grain processing are becoming more popular as a means of replacing aquatic weeds and grasses to save labour costs in pond culture. The yield of grass carp is usually 1 000-3 000 kg/ha, which accounts for 15-40 per cent of the total production.

Intensive culture in cages in China

In intensive culture systems in cages, grass carp are usually stocked as major species. Cages are usually about 60 m², with a depth of 2-2.5 m. 250-500 g fish are stocked at 10-20/m³, depending on the targeted production. In addition, 30-50/m³ Wuchang fish (bluntnose black bream, Megalobrama amblycephala), are also stocked at a size of 80-125 g. Silver and bighead carp are also stocked at 1 per cent of the total, as 'cage cleaners'.

The fish are fed with aquatic weeds/terrestrial grasses and pelleted or other commercial feeds. The culture period is usually 8-10 months and the yield is normally 30-50 kg/m³. Grass carp usually account for 60-70 per cent of the total production. Cage culture of grass carp through the use of commercial feeds involves relatively high production costs.

Feeding efficiency is not always as high in cage culture as in pond culture so, where terrestrial grass and aquatic weeds are locally abundant, collecting them and applying them in cage culture usually requires less labour input as the transportation is limited.

Grow-out systems in other countries

The grow-out of grass carp is mainly conducted in earthen ponds and cages in Vietnam. Polyculture with other species (e.g. silver carp, common carp, rohu and mrigal etc.) is common. Grass carp may be stocked as either major or secondary species. Grass carp usually account for 60 per cent of the total stocking density of 1.5-3 fish/m² (dependent on the level of intensity) in ponds and the fingerling size is 5-6 cm (mountainous areas) and 12-15 cm (lowlands).

The stocking rate in cage culture is 20-30 fish/m³ but much larger fingerlings are used (normally 50-100 g). Grass carp are usually fed with terrestrial grasses, cassava leaves, banana stems and maize leaves in grow-out culture. Grass carp production usually accounts for 60 per cent of total production (7-10 tonnes/ha) in ponds. The marketing size for grass carp is 1-1.5 kg and 1.5-2.5 kg in ponds and cages respectively.

In India, grass carp are cultured as an important species in pond-based composite systems consisting mainly of Indian major carps and Chinese carps. The grass carp stocking density depends mainly on the availability of aquatic weeds and terrestrial grasses but is usually 5-20 per cent of the total. Aquatic weeds (Hydrilla, Vallisneria, Wolffia) and terrestrial grasses such as Napier grass and other hybrid grasses are the major feeds in grass carp farming. Normally, grass carp reach 0.5-1.5 kg in 8-10 months (John Stephen Kumar, pers. comm. 2004). The total production from such systems can reach 8-10 tonnes/ha/yr.

Feed supply

Grass carp can be reared with commercial feeds or natural food, such as aquatic weeds and grasses. They prefer relatively low fertility. Production is mainly limited by water quality. The commercial feeds used for grass carp are relatively low in protein (28-30 per cent) and their raw materials include soybean cake/dregs, rapeseed cake and wheat bran etc. Aquatic weeds can be collected from natural water bodies. Terrestrial grasses can be grown on the pond dyke with organic manure.

Harvesting techniques

Both selective and total harvesting are practiced for grass carp. Selective harvesting is usually conducted in the early morning (because temperatures are relatively low and for morning sales) during late summer and autumn. Individuals of marketable size are selected after netting (a single netting for each harvest). Total harvesting is carried out at the end of the culture period. Several nettings are usually carried out before total drain-down of the pond. All the fish are harvested at the end of the year, either for marketing or for restocking (individuals below marketable size) for the next production cycle.

Handling and processing

Grass carp is normally sold live or fresh. A small quantity of the production is processed by ready-to-eat food stores; in this case the most commonly used processing method is deep frying.

Production costs

The production cost of grass carp vary according to the culture practice used but are normally about USD 0.50/kg of fish produced. Feed costs comprise the largest portion of production costs.

Diseases and control measures

Farmed grass carp are rather susceptible to various diseases. Major diseases and methods of control are listed in the table below.

AGENT	TYPE	SYNDROME	MEASURES
Reovirus (GCRV)	Virus	Red muscle caused by haemorrhage; red fin; red operculum and enteritis; high mortality (30-50 per cent of infected fish)	Vaccination through injection; disinfection of fish seed and culture environment with chlorine-compounds, quicklime and potassium permanganate; Chinese Rhubarb (Rheum officinale); sweet gum leaves (Liquidambar taiwaniana); cork tree bark (Phellodendron) and skullcap root (Scutellaria baicalensis)
Aeromonas sobria; Aeromonas hydrophila; Yersinia ruckerri; Vibrio sp.	Bacteria	Hyperaemia at different positions of body, such as jaws, mouth cavity, operculum, fin-base and whole body when serious; protruded eyeball; swollen anus; expanded belly; erected scales; gill rotten and reduced feeding etc; high mortality of fish	Disinfect the fish and culture environment with quicklime and potassium permanganate; "Yu Tai III" (commercial drug of multi herb ingredients) through medicated feed
Aeromonas punctata f. intestinalis	Bacterium	Red spot on the belly; enteritis; red and swollen anus; expanded belly and losing appetite	Disinfection of culture environment with bleaching powder and quicklime; sulphaguanidine and furazolidone; Chinese herbs (garlic, Euphorbia humifusa, Aclypha australis, Polygonum hydropiper and Andrographis paniculata)
Myxococcus piscicola	Bacterium	Rotting of gill filament; congestion of inner membrane of operculum; small round transparent portion on the operculum and gill filament attached with mud	Bathing fish in 2-2.5 per cent saline water; pond disinfection with quicklime and chlorine compounds; Chinese herbs such as Galla chinensis, Sapium sebiferum and Chinese rhubarb; furazolidone
Pseudomonas fluorescens	Bacterium	External haemorrhage and inflammation; losing scales; congested fins and rotten fin rays	Careful handling during transportation and stocking; disinfection of pond with bleaching powder; sulphathiazole; Chinese gall (Galla chinensis)
Bothriocephalus sp.	Tapeworm	Physically weak; reduced feeding; opening mouth; very high mortality	Disinfection of pond with quicklime and dipterex; pumpkin seed through medicated feed
Dactylogyrus sp.	Helminth	Weak physically; dark body colour; slow moving; reduced feeding and difficult in breathing	Spraying of quicklime and dipterex in pond; dipping the fish with dipterex or potassium permanganate solution
Ichthyophthirius multifiliis	Protozoan extoparasite	Attached to skin and gill filaments; form whitish sac on body surface; high mortality	Thorough disinfection of pond with quicklime; mercury nitrate (banned); Malachite blue (poorly effective)
Sinergasilus (female)	Copepod	Difficulty in breathing; damaged gill; inflammation and rotting of gill filament; madly circle on the water surface and die of exhaustion	Pond disinfection with quicklime; spraying of dipterex or ferrous sulphate or copper sulphate

Suppliers of Pathology Expertise

Assistance can be provided from the following sources:

• Research Institute of Hydrobiology, CAS, Wuhan City, Hubei Province, China.
• Shanghai Fisheries University, Shanghai, China.
• Pearl River Fisheries Research Institute, CAFS, Guangzhou City, China.
• Freshwater Fisheries Research Centre, CAFS, Wuxi, Jiangsu Province, China.
• Zhejiang Provincial Freshwater Fisheries Research Institute, Huzhou City, Zhejiang Province, China.
• The Central Institute of Freshwater Aquaculture (ICAR), Kausalyaganga, Bhubaneswar, 751002, Orissa, India.

Statistics

Production statistics

Global production of cultured grass carp was only 10 527 tonnes in 1950. By 2002 it had reached 3 572 825 tonnes, an increase of more than 339 times in 52 years, and accounted for 15.6 per cent of global freshwater aquaculture production. During the decade 1993-2002, the average annual growth rate of cultured grass carp production was 10.1 per cent globally and 9.9 per cent in China. Expansion in the rest of the world during this decade was, from a relatively tiny baseline, much faster (17.8 per cent/yr).

However, some slow-down seems to be occurring, since farmed grass carp production only grew by 3.3 per cent between 2001 and 2002, both in China and globally. Production fluctuated quite wildly in many countries in the decade 1993-2002. Production in India, which was about 13 000 tonnes in 1993, reached a peak of over 137 000 tonnes in 1999 but had fallen to less than 48 000 tonnes by 2002. However, production in one of the other major producers, Egypt, increased steadily throughout the decade.

The global value of global grass carp aquaculture production was US$ 2.92 billion in 2002, an annual expansion rate between 1993 and 2002 of 7.5 per cent/yr. The slower growth rate in terms of value, as compared to volume, was mainly due to changes in the valuation of the Chinese RMB yuan against the US dollar.

Market and trade

The major producer of this species is China where, traditionally, grass carp are consumed fresh. Most of the production is marketed fresh, either as whole fish or as pieces. Very little production is processed. At the present time, grass carp is mainly a locally consumed product but some of those produced in Guangdong province (southern China) are marketed in Hong Kong.

There is no specific data on the quantity of exported grass carp in Chinese statistical information. However, 41 798 tonnes and 4932 tonnes of live fish (species not specified) were exported to Hong Kong and Macao from the mainland of China in 2002, according to the national statistic yearbook of imports and exports of aquatic products. Grass carp must have comprised large proportion of this total.

Grass carp is a low price commodity that is affordable to middle and low income classes in China and other countries. There has been a slight decline in the price of grass carp in the past few years in China. Currently, retail prices are usually USD 0.7-1.0/kg. There are no specific regulations relating to the marketing of the grass carp because the fish is basically for local consumption.

Status and trends

Grass carp has a long history in aquaculture and is one of the most important species cultured in inland water bodies in China. There have been great efforts devoted to research on this species; the most important achievement has been success in the development of induced breeding technology. This ensures a constant supply of seed for large-scale farming.

Another important aspect of research was the study of nutritional requirements and the development of cheap pelleted feed. As this species is easily susceptible to disease, there have also been a lot of studies on disease control under culture conditions. The best-studied disease of grass carp is Haemorrhagic Disease, which has a viral agent. Effective preventive measures, especially a vaccine have been successfully developed and applied. Culture techniques and models for pond, cage and pen culture have also been well developed.

After silver carp, grass carp currently has the largest production in freshwater aquaculture globally. However, the rate of expansion in China (by far the major producer) has been declining in the last several years. Due to the introduction of new species and changes in people's preferences, grass carp is getting less popular now.

Chinese people still prefer to eat whole fish, but whole grass carp are a little too large for the small Chinese families (3 persons mostly) to consume in one meal. It seems that grass carp culture has more potential for development in other countries, especially developing countries. Its fast growth rate, large size, lack of fine inter-muscular bones and, most importantly, feeding habits make the fish an ideal species for culture in these areas. Rapid expansion of its culture outside China may imply that this great potential is being realised. However, appropriate processing technology is required for the fish to enter international markets.

Grass carp not only grow quickly but have a low requirement for dietary protein. They can be produced at low cost by feeding them with aquatic weeds, terrestrial grasses and by-products from grain processing and vegetable oil extraction. Seed can be produced through induced breeding at a large scale and very low cost. The culture of grass carp can be well integrated into crop farming and animal husbandry, to maximise the utilisation of natural resources.

On the other hand, it is a large fish without fine inter-muscular bones. It is acceptable to consumers in many countries and it very likely has good potential for development. The market for grass carp is close to saturation in the eastern part of China, where aquaculture is well developed now. However, there is still a considerable potential market in central and western China and many other developing countries.

Main issues

Pond based polyculture of grass carp does not have much negative impact on environment. The integration of grass carp - grass cultivation - pig rearing is an ecologically sound production model. However, large-scale intensive culture of grass carp with commercial feeds in cage/pen in shallow open-water may pollute the environment by discharging various wastes, which might accelerate the process of eutrophication. Besides, grass carp is more easily susceptible to some diseases. Poor management in fish health might results in extensive use of different chemicals and drugs, which may affect the quality of the fish and pollute the water at the same time. For the convenience and reducing labour input, farmers are using more and more pellet feed in grass carp culture in pond and cage/pen in open water. Wasted feed and discharge of nutrients may cause adverse impact on the environment.

Responsible aquaculture practices

Several issues need to be addressed in considering responsible aquaculture practices for grass carp culture:

• The first is the use of antibiotics and other drugs in disease control in the intensive culture of grass carp, which are more easily susceptible to various kinds of diseases than other carp species. Due to high stocking densities and poor water quality resulting from various wastes such as unutilised feed and fish faeces, grass carp are often infected with bacterial, viral and parasitic diseases. Antibiotics and other chemicals are sometimes used for treatment. This form of abuse may cause negative impacts, either directly or indirectly, on consumers. Efforts should be made to ensure that reasonable stocking densities, good feeding practices and quality feeds (for other fish in the pond), and good water management are used to minimise the occurrence of these various disease problems. The relevant government regulations must be strictly observed whenever chemicals and drugs are used.
  
  
• The second is the impact on the natural environment of intensive grass carp culture. Presently, the feed used is usually cheap and the FCR is high (usually >2:1). Thus a rather small proportion of the feed is utilised by the fish. The unutilised portion and the wastes discharged by the fish can cause significant environmental impacts and may accelerate eutrophication. Careful planning of cage and pen culture developments inland water bodies, especially shallow lakes, is very important. The utilisation of natural feeds such as aquatic weeds and terrestrial grasses can reduce these adverse impacts. The use of highly digestible feeds and better feeding practices can also assist. Similar problem exist when grass carp are intensively farmed in ponds. With the increasing use of artificial feeds, unutilised feed and other wastes accumulate in the ponds, whose contents are normally totally discharged into natural water bodies at the end of culture operations. Reasonable stocking densities, integrated fish farming, and careful feeding management are highly recommended in order to minimise environmental impact.
  
  
• A third issue is the genetic quality of the seed used in farming. Artificial breeding of this species has been practiced for four decades in China. Breeding control was not always regarded as having high importance by every hatchery operator in the past. Inbreeding actually happened in quite a few farms in the past. This caused a degradation of the quality of seed produced for culture. This may result in poor growth performance and less disease resistance. The latter problem can also bring another dilemma - increased use of antibiotics and other drugs. Therefore, induced breeding of grass carp should be carried out with carefully maintained broodstock of genetic quality.

How Much Fish Oil do YOU Need to be Healthy?

How Much Fish Oil do YOU Need to be Healthy?
by: Emile Jarreau


I think it's safe to say that just about everyone has heard about the healthful benefits of adding fish oil to your diet. The Omega 3 Fatty Acids it contains, has been linked to positive effects in humans including lower blood pressure, lower triglycerides and overall cholesterol levels, and even possible reducing the effects of certain types of cancers including colon, breast, and prostate cancer. It has been included in numerous medical studies as being INCREDIBLY helpful in lowering the risk of heart disease for those that have taken significant amounts of Omega 3 over their lifetime. This begs the question, “How much is enough?”

The answer can be tough and there is perhaps no EXACT answer, but a few variables must be looked at when deciding on how much of it is enough for you is.

First of all, let's look at how age can play a role. Younger people need a higher dose of fish oil than older folks do. This is likely due to the fact that younger people have higher metabolisms and are more active. This results in their bodies burning off higher amounts of calories and fats that they ingest. Older people on the other hand, are usually more sedentary and don't need quite as much fish oil to achieve the same benefits from taking the supplement.

Another factor that plays a role in researching the amount of fish oil you may need in your diet is the quality you are taking. It is readily available in capsule and liquid form anywhere that vitamins are sold, but not all is created equal. The fact is the quality and concentration of fish oil over the counter can vary greatly. You'll want to choose a quality fish oil that is at least health food store grade, and preferably pharmaceutical grade. The higher quality of it, the less you will have to ingest to experience the health benefits.

Finally, the last factor to consider when deciding what dosage of fish oil to take pertains to your particular medical condition. For instance, if you have high cholesterol, or a high risk of heart disease or high blood pressure, your doctor may prescribe a higher than normal dose for you. This is for your DOCTOR to decide though, as it is not advised to self prescribe more than is recommended on the product label itself.

The GENERAL rule of thumb is to take between 2.5 and 3.5 grams of fish oil per day. It is recommended that you visit with your doctor and discuss with it including both the positive and potentially negative effects of taking fish oil. Included in your diet in the right amount, containing omega 3 fatty acids can be one of the smartest and most healthy things you ever do for yourself and your body.


About The Author
Emile Jarreau, aka, Mr. Fat Loss is fascinated by health, nutrition and weight loss. For more great info about fish oil for losing weight and keeping it off visit http://www.MrFatLoss.com

The author invites you to visit:
http://www.MrFatLoss.com

Article Source:
http://www.articlecity.com/articles/health/article_8692.shtml

Catfish fish morphology

Catfish fish morphology.

catfish fish is one type of fish from catfish groups. The length of adult catfish reached 120 cm. This body size is a measure of body belonging to the fish catfish species. Elongated shape with a dominant color such as silver glittery white on the back and bluish. Body color silvery glow very bright as a child, so many people who keep the aquarium as ornamental fish. This silver color will fade after the larger catfish.

Just like other catfish, catfish do not have the stature aka slippery scales. Form a relatively small head. Her mouth is located at the lower end of the head. In the corner of his mouth are two pairs of whiskers that serves as a search tool feed and tentacle while swimming. At the back there are fins with a strong fingers that can turn into shaft. soft fingers fruit numbered 6-7.
form symmetrical forked tail fin. In the pectoral fin is 12-13 fingers - fingers soft and one hard fingers that function as shaft. Anus fin length, consisting of 30-33 soft radius. Meanwhile, in the belly fins are 6 soft fingers.

source: Khairul Amri, S.Pi. M. Si and Khairuman, S.P, AgroMedia Pustaka, 2008.

Snakeskin

SEPAT SIAM
Snakeskin consists of several types, but the famous are only two kinds of sepat (Trichogaster trichopterus) long, 12 cm maksimuni his clan sepat siam (Trichogaster pectorahs) the maximum body length of 25 cm. Snakeskin first type is not cultivated, while sepat siam a freshwater fishery commodities mainstay widely cultivated.
Snakeskin Siamese inserted into Indonesia from Thailand through Malaysia in 1934. This fish had been cultivated for the first time in Indonesia in 1935. These fish are widely scattered throughout the territory of Indonesia in 1937. Not surprisingly, the Siamese sepat also found living in a swamp.
Siamese Snakeskin is an important economic fish is very popular used as salted fish. Siamese sepat menu is fried salted usually served as a vegetable side dishes complement the menu of popular tamarind in Jakarta and Java Bar • at. Therefore, this type sepat very widely known and cultivated in various regions in Indonesia.


Classification
Phyllum: Chordata
Class: Pisces
Order: Anabantoidae
Family: Belontiidae
Genus: Trichogaster
Species: Trichogaster pectoralis
Foreign names: snakeskinned gouramy, spotted gouramy
Local name: sepat siam
Morphological characteristics
Snakeskin Siamese similar to carp, but has a body size smaller. There are black spots in the middle of the stem tail, this fish lehingga called spotted gouramy. In addition, the color of his piebald like snake skin makes this fish is also named snakeskinned gouramy. Meanwhile, a nickname given because sepat siam than many in Siam, Thailand allegedly given because the shape of a larger body than other types Spat.
Eating Kehiasaan
Siamese Snakeskin is the original fish swamp, from the sweet-water marsh to brackish water swamp. This fish-eating fish belong to all (omnivores). Feed primarily plankton, algae, water plants, and small organisms that live in waters where he grew up.
source: Khairul Amri, S. Pi, MSI, and Khairuman, SP Agromedia library, 2008

Fish Tawes, java carp, silver barb

Tawes


Tawes including one type of freshwater fish are quite popular Indonesian society. Tawes is still small is usually processed into dried salted fish. The reason, this fish is relatively thin and contains little fat, so that when dried in the sun will quickly dry and not smell rancid. Meanwhile, large Tawes cooked in a fresh state for having the taste and aroma of delicious meat, in addition to Indonesia, Tawes can be found in Laos and Vietnam.
Classification
Tawes is one of the original fish that Indonesia country, many found on the island of Java. This is also the cause Tawes has the scientific name Puntius javanicus. However, transformed into Puntim gonionotus, and finally turned into Barbodes gonionotus. This Berikul complete classification.

Pyllum: cordata
Class: Actinopterygii
Order: Cypriniformes
Family: Cyprinidae
Genus: Barbodes
Species: Barbodes gonionotus
Foreign Name: java carp, silver barb
I
Local Name: Tawes, taweh or alum, lampam Java
Source: Khairul Amri, S. Pi, M. Si and Khairuman, SP Agromedia Pustaka, 2008

Cultured of Aquaculture Species Milkfish (Chanos Chanos)

Information on the culture of the milkfish (Chanos chanos) from the FAO Cultured Aquatic Species Information Programme.

biological features

Body fusiform, elongated, moderately compressed, smooth and streamlined. Body colour silvery on belly and sides grading to olive-green or blue on back. Dorsal, anal and caudal fins pale or yellowish with dark margins. Single dorsal fin with two spines and 13-17 soft rays. Short anal fin with two spines and 8-10 soft rays, close to caudal fin. Caudal fin large and deeply forked with large scale flaps at base in adults. Pectoral fins low on body with axillary (inner basal) scales. Pelvic fins abdominal with axillary scales and 11 or 12 rays. Scales cycloid, small and smooth, 75-91 on lateral line. No scutes (modified pointed scales) along belly. Transparent 'adipose' tissue covers eye. Mouth small and terminal without teeth. Lower jaw with small tubercle at tip, fitting into notch in upper jaw. No bony gular plate between arms of lower jaw. Four branchiostegal rays supporting underside of gill covers. Gill rakers fine and numerous. Attains typical length of one metre but may reach maximum length of 1.8 m (male).

Profile

Historical background

Milkfish farming in Indonesia, Taiwan Province of China and the Philippines started about four to six centuries ago. Culture methods in a variety of enclosures are constantly being improved upon. Since the 1970s, large investments have been made in the Philippines (as well as in Taiwan Province of China, Indonesia and Hawaii) in terms of infrastructure, research, credit and training in support to the milkfish industry. For example, the Southeast Asian Fisheries Development Center (SEAFDEC) Aquaculture Department (AQD) was established in Iloilo, Philippines in 1973 with a special remit to find solutions for milkfish aquaculture problems. Government agencies and fisheries institutions were also involved in a national effort to intensify milkfish farming from the mid 1970s until now. In this work, research and development on farming systems, breeding and fry production technologies was carried out. There was no attempt at genetic improvement but fry translocation and trade occurred between Indonesia, Taiwan Province of China and the Philippines and geographic variations and heterogeneity were documented. More recently, unconfirmed reports indicate that milkfish are now being cultured to fingerling or juvenile size in the South Pacific Islands and in Singapore as tuna bait.

Milkfish farming was previously a traditional industry, with little emphasis on producing sexually mature, reproductively active fish in captivity. The traditional milkfish industry depended totally on an annual restocking of farm ponds with fingerlings reared from wild-caught fry. As a result, the industry suffered from regional, seasonal and annual variations in fry availability. These variations are generally unpredictable, and may be quite large over short periods of time.

Thus, the central problem faced by the international milkfish industry was to find a way to produce a reliable, adequate, high quality supply of milkfish fry that was not subject to large unpredictable variations in time and space. During the past decade, much progress has been made, particularly in regard to milkfish propagation and the mass production of fry by private hatcheries, research institutions and government agencies. Instead of relying on wild-caught fry, milkfish farms in the Philippines, Taiwan Province of China and Indonesia now obtain the majority of their fry from hatcheries, mainly due to the significant shortage of wild-caught fry.

Habitat and biology

Milkfish (Chanos chanos) is the only species in the Family Chanidae. Its distribution is restricted to either low latitude tropics or the subtropical northern hemisphere along continental shelves and around islands, where temperatures are greater than 20 °C (Red Sea and South Africa to Hawaii and the Marquesas, north to Japan and south to Victoria, Australia; and in the Eastern Pacific from San Pedro, California to the Galapagos).

Adults occur in small to large schools near the coasts or around islands. They are well developed, migratory, large (up to 1.5 m and 20 kg), and mature sexually in five years. Milkfish only spawn in fully saline waters. The activity is most often correlated with the new or full moon phases, takes place mostly in the night and, in most regions, has one or two seasonal peaks. In the natural environment, spawning takes place near coral reefs during the warm months of the year, and populations near the equator spawn year-round. Juveniles and adults eat a wide variety of relatively soft and small food items, from microbial mats to detritus, epiphytes and zooplankton.

Milkfish is a heterosexual fish; hermaphrodism has not been reported. In natural spawning stocks the sex ratio is almost equal, with a slightly higher amount of females. The determination of sex is very difficult, because there are no easily identifiable morphological differences between males and females; however, the pheromone PGF2a (prostaglandin) has been found to be an effective way to identify mature male milkfish.

Milkfish eggs (1.1-1.2 mm in diameter) and larvae (3.5 mm at hatching) are pelagic and stay in the plankton for up to 2-3 weeks. Egg division begins an hour after and hatching occurs 35-36 hours after spawning. In the wild, eggs are probably released in deeper oceanic waters and in the outer reef region. Older larvae migrate onshore and settle in coastal wetlands (mangroves, estuaries) during the juvenile stage, or occasionally enter freshwater lakes. The larvae eat zooplankton and can thrive and grow in water as warm as 32 °C. They then migrate onshore and where they can be caught by fine-mesh nets operated along sandy beaches and mangrove areas; these 'fry' are 10-17 mm long and are used as seedstock in grow-out ponds, pens and cages. In the wild, juveniles are found in mangrove areas and coastal lagoons, and even travel upriver into lakes; they go back to sea when they get too large for the nursery habitat, or when they are about to mature sexually.

Milkfish can reach a maximum size of 180 cm SL (male/unsexed) and 124 cm SL (female). The maximum recorded weight and age is 14.0 kg and 15 years respectively. Resilience is low, with a minimum population doubling time of 4.5 - 14 years. Its fisheries importance is highly commercial, especially in aquaculture, and it is also used in game fish as bait. It is especially valued as a food fish in Southeast Asia.

Production

Production systems

Seed supply

Milkfish fry can either be obtained through collection from coastal areas or littoral waters or can be produced in captivity. The supply of wild fry is often unpredictable; catches in recent years have diminished and cannot satisfy the demand from ongrowing farms.

Fry from captive broodstock and spawners

To develop broodstock under captive conditions, large juvenile milkfish may be stocked, fed and maintained in floating sea cages in protected coves or in large, deep, fully saline ponds (as practiced in the Philippines), or in large deep concrete tanks on land (as practiced in Indonesia and Taiwan Province of China), until they reach sexual maturity with an average body weight of at least 1.5 kg. Land-based broodstock facilities are entirely dependent on fresh pumped seawater supplies and are often integrated with a hatchery.

Broodstocks reach maturity in five years in large floating cages, but may take 8-10 years in ponds and concrete tanks. On average, first-spawning broodstocks tend to be smaller than adults caught from the wild. As a result, first-time spawners produce fewer eggs than wild adults, but larger and older broodstocks produce as many eggs as wild adults of similar size. Broodstocks of about 8 years old and averaging 6 kg produce 3-4 million eggs.

Breeding milkfish in captive conditions and the mass production of fry, as practised in Taiwan Province of China, Indonesia and the Philippines, is mostly dependent on natural spawning, which assures high survival rates. Artificial induction is not normally used. On days when natural spawning occurs, the fish may feed less than usual but show increased swimming activity and exhibit chasing, occasional leaping, and water-slapping activities from late noon to early evening. Spawning usually takes place around midnight but daytime spawning sometimes occurs.

Wild-caught fry

Wild-caught fry are collected with fine-mesh seines and bag nets of various indigenous designs in the Philippines, Taiwan Province of China and Indonesia. The most commonly used gear are push net 'sweepers' and dragged seines.

Hatchery production

Milkfish hatcheries consist of larval rearing tanks, culture tanks for rotifers (Brachionus) and green algae (e.g. Chlorella) and hatching tanks for brine shrimp (Artemia). Larval rearing may be either operated in outdoor or indoor systems, depending on the specific conditions in the countries where fry are being produced.

Hatchery operations utilise either intensive (high stocking density, high volume tanks, daily feeding and water exchange) or semi-intensive (low stocking density, high volume tanks, minimal water exchange, feeding with mixed diet) systems, with an average survival rate of 30 percent (from stocked newly-hatched larvae). After hatching, the larvae are ideally kept at 50/litre in hatchery tanks (either concrete, fibreglass, canvas or polypropylene-covered earthen tanks) maintained with Chlorella and fed with rotifers during the early stages and later with copepods or brine shrimp for a total of 3-4 weeks. Following this, their size ranges between 2-3 cm and they are ready for transport to nurseries.

The fry may change hands two or more times before being used for grow-out; each time this happens, they are sorted and counted, transported, and stored for different periods of time. Fry are a highly perishable commodity and some of them die during gathering, storage, transport, nursery rearing and grow-out. The technologies for fry storage and transport are generally effective, although perhaps not yet optimised. Fry are stored in a cool place in plastic basins or clay pots at 100-500/litre, in water of 10-25 per cent, which is renewed daily. Dealers may store fry for 1-7 days, depending on the demand. Fry can be maintained on wheat flour or cooked chicken egg yolk for 1-2 weeks but soon begin to die, despite continued feeding. Recently, micro-encapsulated feeds have become commercially available for finfish but the cost compared to conventional live feeds is higher.

Nursery

Nursery operations in milkfish producing countries vary according to established cultural practices.

In Taiwan Province of China, where commercial hatchery and nursery productions are integrated enterprises, milkfish fry are generally grown in either earthen ponds or elevated canvas or concrete tanks at intensive stocking densities of >2 000/litre.

In Indonesia, a well established backyard-type nursery is used. This consists of a series of elevated canvas or concrete 1-2 tonnes tanks and similar stocking densities to those used in Taiwan Province of China are employed.

In the Philippines, milkfish nurseries are integrated with grow-out facilities, where wild-caught or hatchery-reared fry are first acclimated into nursery compartments which comprise one third to one quarter of the total area of the Brackish water pond. Fry are stocked at a density of up to 1 000/litre and are fed with a naturally-grown micro-benthic food known as 'lab-lab' which grows on the fertilised pond bottom. Nursery rearing has also been carried out in hapa type suspended nylon nets installed in Brackish water ponds or lagoons and in freshwater lakes within the grow-out compartments, a traditionally practice in the Philippines. When natural food is becoming depleted, artificial feeds such as rice bran, corn bran, and stale bread or formulated feeds are provided. In about 4-6 weeks, the fry grow to 5-8 cm juveniles, which is the ideal size for releasing into grow-out ponds or pens. Depending on the desired grow-out period, juveniles or fingerling size milkfish are kept in nurseries or transition holding tanks up to the required stocking size of 30-40 g. Nursery rearing from fry to fingerling size normally achieves 70 percent survival.

Ongrowing techniques

Milkfish may be ongrown in ponds, pens or cages. Pond culture

Culture of milkfish in ponds may be in shallow or deep water systems.

Shallow water culture is practiced mainly in Indonesia and the Philippines. Milkfish are traditionally cultured in shallow Brackish water ponds in which the growth of benthic algae is encouraged through inorganic or organic fertilisation. Milkfish will survive on benthic algae alone only if the productivity of the algae exceeds the grazing rate of the fish; otherwise, supplemental commercial feeds are applied. The 'lab-lab' culture system in the Philippines is equivalent to shallow water culture in Taiwan Province of China. 'Lab-lab' is the term used in this country for the algal mat (and all micro-organisms associated with it) in the ongrowing ponds.

Brackish water ponds in the Philippines were mostly excavated from 'nipa' and mangrove areas. Shallow water pond design generally consists of several nursery and production ponds with a typical area of 2 000 m² for nursery ponds and 4 ha for production (ongrowing) ponds. Typically, ponds have a depth of 30-40 cm and are provided with independent water supplies.

The average yield of a typical integrated nursery, transition and shallow grow-out system that produces 3 crops a year is 800 kg/ha. Modified modular pond designs consisting of a series of grow-out compartments with a maximum of eight crops a year have been shown to increase yield to a high as 2 000 kg/ha.

Deep water culture was developed in the mid 1970s in response to the decline of profitability of shallow water culture, and the limited and increasing value of land and manpower resources. Deep-water ponds provide a more stable environment and extend the grow-out period into the winter season. Most deep-water milkfish ponds have been created by converting either shallow water ponds or freshwater ponds, with a depth of 2-3 m. Production from these systems has sharply increased in Taiwan Province of China, having expanded from 23 percent of the total production in 1981 to 75 per cent in 1990.

Most milkfish ponds in the Philippines and Indonesia are of the extensive and semi-intensive type, with large shallow pond units, tidal water exchange, natural food, minimal use of fertiliser alternating with commercial feeds and other inputs, and low to medium stocking rates (50 000-100 000/ha). The Taiwanese method of production, on the other hand, employs intensive stocking densities (150 000-200 000/ha). Few diseases or infestations have been recorded so far in milkfish grow-out farming in these Asian countries.

Pen culture

This system was introduced in the Philippines in 1979 in the Laguna Lake. At that time, the lake had a very high primary productivity, which met the nutritional needs of milkfish. Because of the low rate of input and the high rate of return, the pen culture area increased sharply from 1973 to 1983, and exceeded more than 50 percent of the total lake surface, which is 90 000 ha. As the primary production of the lake could not meet this sudden expansion of aquaculture, and feeding became necessary to meet the nutritional requirements of the cultured fish, the pen culture practices developed in lakes were later introduced into inter-tidal areas in the Philippines along coves and river estuaries as well. Pen operators stock fingerlings at 30 000-35 000/ha and provide supplemental commercial diets. However, disease spreads among culture pens and causes mass mortality. Government regulations are now being considered to maintain sustainable yields from this type of farming.

Cage culture

Fish cages are smaller and more restricted enclosures that can be staked in shallow waters or set-up in deep water with appropriate floats and anchors. Cage farming of milkfish is commonly carried out in marine waters along coastal bays. Stocking rates (in the Philippines) are quite high, from 5 up to 30/m^³.

Feed supply

In the past, traditional feeding practices for milkfish grow-out production have consisted of natural food ('lab-lab') or a combination of phytoplankton and macroalgae (Enteromorpha intestinales, Cladophora spp. or Chaetomorpha linnum) encouraged by fertilisation. In the 1980s however, special commercial feeds for milkfish were developed and became almost exclusively used. As cage and pen culture technology proliferated in the 1990s, both in marine and inland waters, extruded milkfish feeds were further developed into floating and semi-floating forms, while sinking forms were used for pond and tank-based grow-out. Feed supplies are now manufactured commercially in the form of starters, growers and finishers, which are administered according to the production stage of the milkfish.

Harvesting techniques

Milkfish are normally harvested at sizes of 20-40 cm (about 250-500 g). There are three known methods used for harvesting milkfish:

• Partial harvest. Selective harvest of uniformly grown milkfish from grow-out facilities (i.e. cages, pens, ponds, tanks) using seine or gillnets, retaining the undersize fish and harvesting only the commercial sized stocks, with an average body weight of 250 g or larger.
  
  
• Total harvest. Complete harvest in one crop period from grow-out facilities (i.e. total draining of ponds by gravity or pump, hauling of the entire net cage structure, seining or the use of gillnets in pens). The harvest size at this stage may vary from 250-500 g.
  
  
• Forced harvest. Emergency harvesting, regardless of fish size or grow-out stage, which is carried out during 'fish kills' due to oxygen depletions that are attributed to algal blooms, red tide occurrence, pollution or other environmental causes.

Handling and processing

200-400 g milkfish are harvested and marketed mostly fresh or chilled, whole or deboned, frozen, or processed (e.g. fresh frozen deboned, fresh frozen deboned descaled, and smoked fish deboned). In general, all marketed milkfish are produced in farms, only a few being caught from natural waters. In some countries (e.g. the Philippines) fishing for adult milkfish is officially banned in order to protect the natural broodstocks.

There are two known post-harvest processing techniques for milkfish, which are the traditional (i.e. drying, fermentation and smoking) or non-traditional methods (i.e. bottling, canning and freezing) and value-added products such as 'surimi' and deboned products as practiced in Taiwan Province of China and in the Philippines.

Regulations and standard protocols for manufacturing milkfish products exist for both domestic consumption and export, as follows:

• Good Manufacturing Practices (GMPs). Plant construction.
• Personnel hygiene and sanitation.
• Standard Sanitary Operating Procedures (SSOPs).
• HACCP compliance.

Production costs

Milkfish farming is a centuries-old industry in Indonesia, Taiwan Province of China and the Philippines. It has been slow to modernise and now faces challenges from competing aquaculture species and current economic realities. The domestic market is large and the export market has globally expanded. Milkfish price and personal income affect the amount of milkfish consumed in the countries of origin. Studies conducted in Taiwan Province of China and the Philippines concluded that price and income had a negative and positive elasticity coefficient, respectively.

The following are the major determining factors affecting the cost of production in milkfish:

• Type of culture system: costs are lowest in systems dependent only on natural food; costs increase as artificial feed is introduced; costs are highest in systems dependent totally on commercial feeds.
• Increasing production: with milkfish production steadily increasing and culture practices becoming more intense, a big surplus of this commodity is foreseen in the near future.
• Cost of feed: feeds account for 60 to 80 percent of the total production cost.
• Low farm-gate prices: on average, the farm-gate price for milkfish is only about USD 2.00/kg in the Philippines. As the supply of milkfish is expected to increase way above demand, fish farmers cannot demand a higher farm-gate price even though they may be spending heavily to cover production costs.
• Lack of post-harvest facilities for value-adding and processing

Diseases and control measures

The major diseases affecting milkfish are included in the table below. In some cases antibiotics and other pharmaceuticals have been used in treatment but their inclusion in this table does not imply an FAO recommendation.

DISEASE	AGENT	TYPE	SYNDROME	MEASURES
Nematode infestation	Capillaria sp.	Parasitic nematode	Emaciated, although shows good appetite in early stage, then weakens, becomes listless, loses appetite & colour pattern darkens; fin & tail rot and skin patches/sores; faeces white & stringy/slimy; scrapes belly against bottom or may start to tremble; larval stage of parasite located in muscle tissue & can be seen through skin, appearing either coiled up or rod-like	Administer trichlorfon (with caution for small fish); niclosamide, levamisole or mebendazole mixed in feed
Anchor worm disease	Lernaea cyprinacea	Parasitic copepod	Parasite visible on skin, head embedded deep in the tissues of the host; haemorrhages and open wounds at site of infection; weight loss; respiratory difficulties; sluggishness; red areas; ulcers; scale loss; fin damage; scraping and sometimes hanging vertically or belly up; parasite length 5 to 22 mm	KMnO4 bath or 0.8-1.1 per cent NaCl (KMnO4 may be lethal to small fish at dosages required to kill Lernaea)
Trichodinosis	Trichodina sp.	Protozoan parasite	Slime covers skin like fog, fins clamped and denuded of tissue	250 ml/litre formalin bath for 15 min
Scolex infestation	Scolex pleuronectis	Helminth parasite	Infestation occurs commonly in the intestine	None stated
Cryptobia Infestation	Cryptobia sp.	Protozoan parasite	Dark coloration; increased mucus build-up; occasional appearance of skin lesions followed by scale loss; difficult or rapid breathing; reduced appetite and weight loss; secondary bacterial infections in advanced stage leading to pale and/or red skin patches and skin & fin rot	Treat with formaldehyde (250 ml/litre) or 10mg/litre malachite green; place infected fish in freshwater bath or treat with effective antibacterial agents
Caligus infestation	Caligus longipedis	Parasitic copepod	Loss of appetite; lethargic swimming; excess mucus production; lumpy body surface	Dip infected fish in freshwater (makes transparent parasite visible); bathe in 150 ppm H2 02 for 30 minutes

Suppliers of pathology expertise

The following are examples of locations where expertise can be accessed:

• Bureau of Fisheries and Aquatic Resources .
• The Southeast Asian Fisheries Development Center.

Statistics

Global annual aquaculture production of milkfish has increased every year since 1997; by 2005 it had risen to nearly 595 000 tonnes, with a value of almost USD 616 million. The most important producers at this time were the Philippines (289 000 tonnes), Indonesia (254 000 tonnes) and Taiwan Province of China (50 000 tonnes).

Market and trade

Producers of milkfish do not usually sell fish directly to consumers, but supply them through cooperatives, brokers, dealers, collectors or wholesalers, and retailers. In general, the majority of fish products are sold in auction markets through dealers, brokers, wholesalers or cooperatives to smaller dealers, and then retailers.

Increasingly, more of the milkfish harvest is processed into value-added forms: smoked, dried, marinated (brined, sweetened), fermented with rice, and canned or bottled in various styles (salmon style, sardine style, Spanish style, smoked in oil, etc.). Some companies in the Philippines now produce frozen prime cuts of milkfish bellies and backs, and even of heads and tails. Milkfish is exported in different product forms: quick-frozen, dried, canned, smoked or marinated.

The Philippines recorded an export of over 17 040 kg of milkfish products to the EU in 2002, valued at USD 58 000. While Taiwan Province of China concentrates on processed and value-added products for export to the USA, Indonesia has strengthened its export of hatchery-reared seedstock to the rest of the Asia-Pacific region for tuna bait and for grow-out.

Status and trends

Research and development

Successful induced spawning and larval rearing of milkfish were first accomplished at SEAFDEC/AQD in 1976-1978. The first generation cycle of milkfish in captivity was completed at AQD when the offspring of a wild female induced to spawn in 1978 in turn spawned in 1983. Since then, milkfish have matured and spawned in floating cages, ponds, and concrete tanks in the Philippines, Taiwan Province of China, Hawaii, and Indonesia. Since the successful completion of larval rearing technology in 1984, fry production has increased significantly, which has not only provided milkfish farmers in Taiwan Province of China with ample supply but also opened an export market to neighbouring countries.

To date no substantial technical and scientific research has been documented from major milkfish producing countries other than the policy and management related research being conducted by the WorldFish Center, the SEAFDEC Aquaculture Department and the Bureau of Agricultural Research and BFAR of the Philippine Department of Agriculture.

Taiwan Province of China, however, has recently developed an improved strain of milkfish through selective breeding process resulting in a golden coloured F1 pioneered by a private farmer; this would accordingly command a better price than the original silvery coloured strain, once introduced in the market.

Development perspectives

The development of more efficient culture systems has resulted in higher milkfish production, which continues to increase.

Diversification of aquaculture in Taiwan Province of China, however, has paved the way for prioritising other high valued commercial marine species of fish, which has affected the growth of the milkfish industry.

Based on current trends, production in the Philippines (which has expanded its traditional land-based milkfish farming from Brackish water fishponds to marine cages in coastal communities through the establishments of mariculture parks) is expected to rise from 289 000 tonnes in 2005 to 369 000 tonnes in 2010. Assuming that the population of the Philippines reached 84 million by the year 2005, at per capita milkfish consumption of 2.5 kg/yr the total milkfish requirement would reach 210 000 tonnes. With the actual milkfish production recorded as of 289 000 tonnes in 2005, there would have been an estimated supply surplus of 79 000 tonnes.In Indonesia backyard hatchery production of milkfish seeds has become a rural industry at the village level. The majority of these hatcheries have further shifted to fry production of high-value species of marine finfish.

Market perspectives

Marketing of milkfish products contribute a lot to the sustainability of the industry in the major milkfish producing countries - Indonesia with its seed production exports, Taiwan Province of China with value-added milkfish products and the Philippines with whole fresh and processed products both for domestic and export markets.

The General Agreement on Tariffs and Trade GATT/WTO impositions of trade restrictions and the EU/US bio-safety and quality control standards are considerably affecting the producing countries and are foreseen to be an added burden among production costs.

Although HACCP from farm to product processing are now strictly observed (for both domestic and export markets) in the major producing countries, farmers and processors view this as another trade barrier that has been set by the importing industrialised countries.

Recommendations

The following recommendations are suggested:

• Opening up markets, both locally and abroad, for value-added products including boneless milkfish would be valuable. The Philippines is the only country in the world to produce boneless milkfish to date. Improving the distribution flow for boneless fish for local markets would also be useful.
• Investment in feed formulation to cut down production costs. Rationing the exact daily feed biomass requirements to reflect actual feed requirements is needed.
• Trimming down marketing layers. Through cooperatives, producers should be encouraged to market production directly to retailers, thereby bypassing the traditional market layers.
• Making public investments for post-harvest facilities.

Main issues

The main issues in milkfish farming can be summarised as follows:

• Producers and consumers have benefited from new technology; however, broodstock technology is still unreliable and fry supply is not fully controlled.
• Milkfish will remain a traditional foodfish in the Philippines, Indonesia and Taiwan Province of China; however, the younger generation tends to avoid eating milkfish because of their bony flesh; thus new markets will be difficult to create.
• High land values and the relatively low value of milkfish mean that farmers will have to introduce new technology to increase unit productivity.
• Milkfish aquaculture will no longer rely only on natural productivity; the use of formulated feed will become the norm.
• More hatcheries, especially in Indonesia and Taiwan Province of China, are expected to come on-stream. This, and improved spawning technology, is expected to decrease fry costs.
• New product forms need to be developed, advertised and marketed.
• As mass production of milkfish fry in hatcheries expands, more fingerlings will become available for the baitfish industry.
• Further research and development on the marketing and processing of milkfish is desirable.

Responsible aquaculture practices

Due to global market demand, major milkfish producing countries have recently been promoting management practices that address food quality and safety issues. At the farm level for example, the Philippines complies with the minimum aquaculture HACCP requirements, from hatchery production to harvest, before milkfish products are processed for export. Taiwan Province of China has introduced product eco-labelling in order to export quality branded processed milkfish products, while Indonesia ensures the quality of milkfish fry when exporting to neighbouring Asian countries and accompanies them with health certificates. Traceability in the use of antibiotics and unregulated drugs is already strictly imposed in these countries.