Carps, the most popular fish

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Carp aquaculture originated in ancient China

Oracle bones – 1,500 B.C.

First aquaculture text – Fan Lee – “treatise of pisculture”

Carp species diversity

-Carp form the largest family (cyprinidae) of all fish

-Carp species vary in size > 6 ft., to < 1” in length

-Many of the smaller cyprinids, i.e. “goldfish” (domestic strains of carassius auratus) are important as ornamentals

- The common carp (Cyprinus carpio) is he most popular for culture and is farmed throughout the world where the temperature is appropriate

Koi (domesticated carp in Japan)

-Koi (domestic carp) is the most popular fish in Japan because of its gorgeous, magnificent, and colorful style.

-In Japanese culture, the Koi represents strength, courage and success in life.

-On international Children’s Day (June 1), Carp windsocks are flown from each home. This tradition symbolizes the parents wishing success for their children’s lives in the future.

Common carp (cyprinus carpio)

1.     Temperature optimum; 20-33 C

2.     Survives 4C (overwintering, metabolic depression)

3.     Tolerates low oxygen levels but optimal growth at > 3 ppm DO (dissolved oxygen)

4.     Algal crashes and resulting complete oxygen depuration are a common cause of carp mortalities

Carp reproduction

1.     Collection of eggs and milt for artificial fertilization

2.     Natural spawning (Dubisch method)

3.     Small (120 – 300 m2) shallow ponds (30 – 60 cm deep) kept grass-covered and dry when not used

4.     When the temperature warms to 18-20C ponds are flooded to 25-3 cm deep

5.     Ponds are then stocked with spawners (broodstock = 2-3 females and 4-5 males)

6.     Spawning occurs within 1-2 days and fertilized eggs are collected from substrate

Lowering egg adhesiveness after Artificial Fertilization

1.     Mixing ration ~1 part milt (sperm) : 100 parts eggs (weight not numbers!)

2.     Urea .3% plus sodium choloride .4% is used as a saline solution for multiple washes, 1 part solution : 10 parts fertized eggs, over a period of 1.5 hours to remove the “stickness” from eggs

3.     A final rinse uses tannin to complete the process lowering adhesiveness of the eggs

Eggs are incubated in upwelling jars (10 I) for 3-3.5 days at 24C

Aftering hatching larvae are reared in upwelling tanks (200 I) 3-4 days at 20-24C

During this time the air bladder inflates and swimming commences

Rearing of carp fry

Fry ( post-yolksac larvae) are reared in small ponds

-If outside, then Predator removal

-Quicklime (pH > 11) CaCO3 + H2O -> Ca(OH)2 + CO2

-Bleach

Pond fertilization

-2 weeks prior to stocking to promote algal growth (food source)

-3:1 to 6:1 N:P ratio

Stocking of fry

-200-400 larvae/m^2

-grow in 30 days to fingerling size

Grass carp (Ctenopharyngodon Idella)

1.     Also known as the White Amur carp

2.     Herbivorous, fry feed on plankton, change to vegetation at ~6’’

3.     > 20 C grass carp feed continuously eating several times their body weight in plant material daily

4.     Rapid growth; live for as long as 10 years

5.     Meat quality is very high and preferred over other carp

Omnivore = Common Carp, bighead carp

Herbivore – Grass carp, silver carp

Carnivore –  Black carp

Bighead carp

1.     Omnivorous fish / they feed on phytoplankton and zooplankton and or pellets

2.     Fourth most important carp species

3.     Very fast growing

4.     Native to Asia

5.     Highly invasive species in the us

6.     Eyes on bottom

Black Carp (Mylopharyngodon Piceus)

1.     Native to Eastern Asia

2.     Introduced to the US in the 1970’s

3.     Black carp are carnivores (meat eater)

4.     They feed on molluscs

5.     Similar to grass carp but gill rakers are fused and hardened to enable crushing of mollusk shells

Intensification of carp monoculture

-Natural production 150 – 300 kg/ha/yr

Fertilization 500 – 800 kg/ha/yr

Supplementary feeding 1-4 mt/ha/yr (soaked grains)

Complete feeds 5-10 metric tons/ha/yr

Polyculture – Tang Dynasty (618-907) A.D.

Polyculture: Rich-fish aquaculture

Advantages

1.     Rich production improved

2.     Additional source of protein and/or revenue

3.     More sustainable, less waste

Disadvantages

1.     Not useful with high-yielding, short stem rice varieties needing shallow water

2.     Not useful with multiple rice cropping; fish growth limited

3.     Need to provide refuges during rich field drainage

4.     Limited use of common insecticides and herbicides

Polyculture: Rice-Azolla-carp aquaculture

1.     Azolla is an aquatic fern (duckweed), that floats on the water surface

2.     It can assimilate atmospheric nitrogen owing to the nitrogen fixation by symbiotic cyanobacteria (blue green alga)living in cavities of azollaleafs

3.     Less nitrogen fertilizer is needed for carp culture