unit 10 carps

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Carps

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Carps• Family: Cyprinidae • Oldest history of culture of all finfish and shellfish• The common carp can be considered domesticated food

fish, also used as sport fish• Low-value fish, suited for large scale production to feed

poor communities in rural areas• Fresh water fish, but can tolerate salinities up to 10-11

(sometimes even grow better at salinities of 5)• Carps have good sense of hearing due to Weberian

apparatus.

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Ostariophysi

milkfish

Common carp, cyprinus carpio

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Ostariophysicharacteristics:• Weberian apparatus• alarm response

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Ostariophysi

specialized bones connect the swimbladderwith the inner-ear (Weberian ossicles)

characteristics:• Weberian apparatus• alarm response

lateral (side) viewdorsal (top) view

skull / inner ear

swimbladder

Weberian aparratus

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Ostariophysicharacteristics:• Weberian apparatus• alarm response

What is the advantage of this connection?

better sound detection (sensitivity)at low frequencies (1-1000Hz)

e.g. sound produced by tail beats of other fish• neighbours in a school• attacking predators)

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Ostariophysicharacteristics:• Weberian aparratus• alarm response

involves• production of an alarm substance (Schreckstoff )

• is given off when specialized dermal cells are ruptured (e.g. biting by a predator)

• behavioural reaction to the presence of the alarm substance in the water (Schreckreaktion )

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Three groups of cultured carps:

Chinese carpsCommon carpIndian carps

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Low input, low cost aquaculture• Low input, low cost aquaculture production of protein food for

domestic consumption and cash income.

• World carp production from aquaculture in 1999 was 14.9 million tonnes, which was 44.7% of the world total aquaculture production in the same year.

• Eight of the top 10 aquaculture finfish in single species production are carps (the other two are tilapia and Atlantic salmon).

• In many industrialized countries, like Australia, carps are regarded as pests. In many populous counties in Asia they are the strategic species for securing rural livelihood and national food security through freshwater aquaculture.

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Chinese carpsHave become more important than common carpSpecies cultured:

• Grass carp Ctenopharyngodon idella• Silver carp Hypophthalmichthys molitrix• Bighead Aristichthys nobilis• Black carp Mylopharyngodon piceus• Mud carp Cirrhina molitorella

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Ctenopharyngodon idella Hypophthalmichthyes molitrix

Aristichthys nobilis Mylopharyngodon piceus

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Niches• mud carp: detritus, role restricted: not large, essentially a

subtropical species, but esteemed by consumers

• silver carp: plankton, mainly phytoplankton

• bighead: macroplankton

• grass carp: herbivorous, macrovegetation (grass, aquatic plants)

• black carp: snails and other molluscs at the bottom, important role in controlling growth of molluscs

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Spawning

Chinese carp don’t spawn naturally in ponds

• larvae and fry are collected from natural spawning grounds

• or through induced breeding

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Collecting wild seed

• Commercial dealers• Eggs and fry caught in rivers with fine mesh nets

in wooden frames• Eggs hatch in fine netting cages after 2-3 days• Fry sorted into species by experts• Transported for sale

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Induced spawning

• Induce spawning by cultured fish through the injections of certain chemicals

• Ripe fish are collected from the farm and are injected– Crude extract of carp pituitary gland (or those

of other mature fish species close to carp)– Partially purified human chorionic

gonadotropin = hypophysation

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Spawning to fry

• Injected fish is placed into spawning ponds or• Netting cages (two males , one female)• Spawning within 12 hours• Eggs collected to hatchery facility• Hatching within 24-30 hours• Larvae use up yolk sac within 3-6 days• Then transfer to nursery pond

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Common carpThree recognized varieties of

common carp:• Orange colored scale carp

(Cyprinus carpio var. flavipinnis)• Partially scaled mirror carp

(Cyprinus carpio var. specularis)• Scale-less leather carp (Cyprinus

carpio var. nudus)

==> scale and mirror carp: faster growth rates

Carp with scales

Mirror carp

Carp with single row of scales

Leather carp

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Common carp• Originates in eastern Europe and western Asia and the

watersheds of the Black, Caspian, and Aral seas.• Can function in an environment with high level of

turbidity because of highly developed hearing and smelling senses.

• Many races and strains by breeding programs e.g. Heyuan carp: grows 30% faster than wild carp, greater disease resistance.

• Cultured in: Asia, Europe, Near and Middle East, parts of Africa and Latin-America (esp. Brazil)

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Feeding

omnivorous:• young carps (< 10 cm): protozoa, zooplankton• larger: benthic organisms, vegetable matter• sucking food organisms from mud:

=> muddy water, weakens base of pond dikes=> addition of artificial feedstuffs

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Indian carpMajor cultured species:• catla Catla catla• rohu Labeo rohita• mrigal Cirrhina mrigala• calbasu Labeo calbasu Catla catla

Labeo rohila Cirrhina mrigala

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Catla catla

• Lives in rivers in Northern India, Pakistan, Bangladesh and Burma

• Zooplankton (= water column) feeder• Fastest growing of the Indian carps: ~350 g in 1rst year• First maturity in the 2nd year of life (~2kg)

Catla catla

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Labeo rohita

• Lives in rivers in north and central India, Pakistan, Bangladesh, Nepal and Burma

• Bottom and column feeder (plant material)• First maturity at the end of 2nd year (~280-500 g)

Labeo rohila

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Cirrhinus mrigala

• Rivers in north India, Pakistan, Bangladesh and Burma• Detritus feeder• Growth rate: ~250 g in the 1rst year (fast growing during

the first four years!)• First maturity at the end of 1rst year

Cirrhina mrigala

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Spawning

• Fry collected from the wild⇒ polyculture

• Artificial spawning⇒ in special „bundh„ types of ponds

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Culture techniquesMost common: ponds• Stagnant or semi-stagnant ponds (small ponds, pools

with running water sometimes used in Japan and Indonesia)

• Sizes: large variety, up to several hectares• Breeding at farm: brood ponds• Common carp: brood- and spawning ponds• For rearing fry: nursery pondsOther systems: experimentally or commercially on small

scale: cage-, rice-field culture, stocking of open water

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CultureMonoculture• Common carpPolyculture• Chinese and Indian carps• Trend towards increasing number of species (China,

India)

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What is Polyculture

Polyculture utilizes natural foods efficiently.

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Polyculture - plankton feeders

Silver carp feed primarily on phytoplankton. Bighead carp feed primarily on zooplankton.

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Polyculture - herbivores

Country/Region Local Name Scientific NameAfrica tilapia Tilapia rendalliIndia rohu Labeo rohita

Cauvery carp Labeo kontiusreba Cirrhinus reba

Indochina ca ven Megalobrama bramulaIndonesia giant gourami Osphronemus goramySE Asia tawes Puntius gonionotusworld wide Zillis tilapia Tilapia zillii

Grass carp feed on aquatic vegetation.

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Polyculture- Bottom feedersCountry/Region Local Name Scientific NameChina mud carp Cirrhinus molitorella

black carp Mylopharyngodon piceuscha cham Mylopharyngodon aethiopsstriped mullet Mugil cephalus

India mrigal Cirrhinus mrigalCauvery carp Labeo kontiusreba Cirrhinus rebanagendram fish Oteochilus thomassi

SE Asia belinka Barbus belinkalampai Barbus lampaimata merah Barbus orphoidestambra Labeobarbus tambroides

Taiwan milkfish Chanos chanosWorldwide nile tilapia Oreochromis niloticus

blue tilapia Oreochromis aureusblack tilapia Oreochromis mossambicus

Common carp are bottom feeders

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Piscivorous fish

Various predator fishes used in polyculture.

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Factors affecting species selection and stocking rates

1. Water temperature2. Market value of fish3. Pond fertilization practises4. Feeding habits of fish5. Tolerance to pond conditions6. Potential of uncontrolled spawning in grow-out

ponds

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Stocking ratesSPECIES CHINA INDIA MALAYSIA T H A I L A N D PANAMA

SIERRA LEONE

Bighead carp 1 - 1 3 10 -Silver carp 12 - 1 3 - -Grass carp 2 - 3 3 - -Common carp 17 - 1 6 10 -Tawes - - - 63 - -Rohu - 38 - 6 - -Mrigal - 6 - - - -Catla - 19 - - - -Tilapia - - - 63 100 160Ophicephalus - - - - - -Cichlasoma - - - - 20 -Notopterus - - - - - 16

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Problems to be solved

• Too specialised feeding habits• Limited choice of species

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Other Culture SystemsOpen water stocking• Chinese-, Indian carps, common carpRice field culture• common carp, in some countries replaced by tilapia and

othersCage culture• experimental• traditional in Indonesia, on small scale in China & Japan

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Breeding season

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Natural spawningOnly common carp spawns naturally in ponds• Done in large grassy ponds• Stock 2-3 males per female per 3-4 hectares• Success is weather dependent• Method: Dubisch method• Maintain proper water temperature (18-22°C),• Maintain correct DO (dissovled oxygen level)• Pond has a grass-covered center for spawning• Need fish of both sexes• Catching wild Carp when they are ready to spawn• Strip eggs and sperm immediately• Fertilize eggs artificially• Transport eggs to incubation area

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Systems used for breeding

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Semi-artificial propagation• Spawners are injected with a single dose of

gonadotropic hormones or Carp pituitary:– Females: 1rst injection 0.3 mg/kg, 2nd 3.5 mg/kg– Males: 2.0 mg/kg

• Stock in newly filled ponds• Spawning takes place within 2 days• Use of hapas: 1 x 1 x 2 m cloth enclosures• Breeding takes placed in hapas• Breeders are then removed• Larvae hatch in hapas

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Artificial Propagation• Requires 2 injections of gonadotropic hormones• Hand-strip eggs and sperm• Perform artificial propagation• Remove stickiness, supervise incubation• Supervise hatching• Transport young fry to rearing ponds• Advantages

– Need for males reduced– Better protection of eggs– Better protection of newly hatched larvae– Good control of first feeding– Better preparation of stocking ponds

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Ripe carp- Gonad

maturation

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Sorting male and female

carp

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Hatching and larval rearing• Hatchlings: transferred to indoor nursery tanks• ==> Desirable to rear the hatchlings undercontrolled

conditions up to fry stage– Stocking rates (20 m2 tank, 0.5 m deep):– 1 million fry (water exchange rate 1 l/ min x m2)

• Natural food, manufactured starter feeds (first hard-boiled eggs, then switch to plankton-rich ponds after 1.5 days.

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StockingMultisize stocking• Stocking of fry, fingerlings and young adults of different

sizes for efficient utilization of different food resources.Multistage stocking• Stocking fish in progressively larger ponds as they grow

in size, reducing the stocking rates as required.Stocking rates

– 4000-5000 fingerlings of 2.5-5 cm length/ha– 2000-3000 fingerlings of 5-10 cm length/ha==> With intensive feeding and aeration higher

ratespossible

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Grow-out timeMonoculture

Europe:– market size: 1 - 2 kg weight– required time: 3 years, South Europe: 2 yearsTropical, semi-tropical regions:– market size: 0.6 - 1 kg– required time: < 1 year

Polyculture: 1-2 years

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Growing carp - Indonesia• Ponds or hapas for spawning• Fry reared in ponds and often sold to fingerling growers• Fingerling sometimes sold at 200g• Grown in rice fields or ponds

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Growing carp - China• Often cultured in polyculture• Common carp often minor component• heavily fed, fertilized and stocked ponds

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Growing carp - Japan• irrigation ponds, small fishponds, running-water ponds,

and floating net cages • stocked in spring (April-May) with 40–100 g fingerlings at

a rate of about one fish per square metre and fed pellets or silkworm pupae 4–5 times daily.

• Fish are sold in the autumn (October or November) at about 800 g average size