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| Effect of Sediment on Growth and Mortality of Red Swamp Crayfish Procambarus clarkii |
| ZHOU Feng,DONG Chao,ZHENG You,HUANG Cheng |
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Abstract The red swamp crayfish (Procambarus clarkii) was divided into three categories by size ,small size of crayfish (post -larvae ,with body weight of 4 .23 ± 0 .258 mg) ,middle size of crayfish (2 .69 ± 0.410 g) and large size of crayfish (7 .55 ± 0 .415 g) .The small size of crayfish(30 caryfish each aquarium) w as raised in a small aquarium (45 cm × 35 cm × 20 cm ) in w hich 1 kg sediment w as tiled .T he middle (18 crayfish each aquarium) and large (6 crayfish each aquarium) size of crayfish were raised in a large aquari-um (80 cm × 52 cm × 25 cm) in which 8 .5 kg sediment was tiled .In the control group ,there was no sedi-ment in the aquarium with five replicates each treatment .The growth ,mortality ,and resistance to hypox-ia and high temperature and the effect of sediment on dissolved oxygen level were tested in the crayfish raised in 5~6 weeks at water temperature from 18 ℃ to 25 ℃ .The results showed that there were signifi-cantly higher specific grow th rate in the crayfish [small sized (7 .82% /d) and the middle sized (0 .90% /d) P<0 .01 ,the large sized (0 .92% /d)] (P<0 .05) in the aquaria with sediment than that in the control aquaria (5 .56% /d ,0 .20 % /d ,and 0 .59% /d for small ,middle and large crayfish) .The small sized cray-fish in the aquaria with sediment had significantly lower mortality than the crayfish in the control aquaria did (P<0 .05) and very significantly great resistance to high temperature than that in the control aquaria (P<0.01) ,without significant differences with the other groups (P>0 .05) .Sediments led to significant-ly enhance the resistance of various sizes of crayfish to hypoxia (P<0 .01) ,even though the sediments re-duced the level of dissolved oxygen .
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Received: 25 December 2015
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