Raising yearling Astacus leptodactylus by mono-culture and polyculture method with Chinese carps hitting market size
2002
Ramin, Mahmoud, National Inland Water Aquaculture Center | DaneshKhoshAsl, A., National Inland Water Aquaculture Center | Karimpour, M., National Inland Water Aquaculture Center | Nosrati, M., National Inland Water Aquaculture Center | MousaviKomle, A., National Inland Water Aquaculture Center
Culture practices have been launched in 4 soil ponds with the surface 'Ó of 400/m with two tests ( treatment) ponds each test ponds with two replicates . In first test pond crayfish stocked with the dencity of 10 ind/m2, its average weight 10 g and lenghth 6.2 cm ( 100000 ind/ ha) also in second test pond by poly-culture practices , chines carps at the concentration of ( 3000 ind/ha) in proportion of 25% grass carp , silver carp 60% and bighead carp 15% and crayfish based on 10 ind/ m2(10g waighte and length6.2 cm ) which the latter replaced common carp in the present stocking management experiments. The Chinese carp stocking size by average were as foliowes : Grass carp 8.3 cm - 20 g , silver carp 6.1 cm -10 g and bighead carp 6cm - 10 g . Control pond with the surface of 1000/m2 stocked with 3000 Chinese carps fingerling at the rate of 10% common carp , silver carp 60%, bighead carp 10% and grass carp 20% (the latter stocking manegement adopted from private farmers in the region ). Crayfish in ponds fed by concentrated food , slaughter-house resdiue , rice bran, kilka , and for the stocked finger!ings fish pellet ,aquatic plants , live-feed which produced in ponds by organic manure . water quality criteria such as Phranged between 7.1-8.82 and Co2 ,ÑîÇ, ÍÑîÇ, N-NH4, and N-No3 were at desirable level in ponds . Water temprature measured 3 times a day the minimum 18.2 0 0 in November , maximum 28.34 0 c in August. Dissolved oxigen showed least in April ( 6.34 mg/1) and high level reached in July (9.93mg/1) . The culture crayfish in addition to artificial feed foraged aquatic plants such as Chara, Spirogyra etc . Biometric data gathered in every 45 days and the resultsobtained as folio wes : Crayfish in mono - culture : Average weight and length in first and second replicates measured 34.12g - 9.2cm and 49.69g-l 1.56cm respectively.
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