Understanding settlement tendencies and substrate preference is essential for king crab stock enhancement because structurally complex habitats provide red king crab juveniles with shelter and protect them from predat...Understanding settlement tendencies and substrate preference is essential for king crab stock enhancement because structurally complex habitats provide red king crab juveniles with shelter and protect them from predation and cannibalism during critical stages of their lives. The growth and survival rates of juvenile red king crab （Paralithodes carntschaticus） from the first juvenile instar stage after settlement from the free-swimming glaucothoe （stage C 1）, to the third juvenile instar （stage C3）, that were reared in aquaria with natural rock, shell, and artificial substrate from June 8 to July 15, 2008 at the Alutiiq Pride Shellfish Hatchery in Seward Alaska were evaluated. The percent of crabs surviving to the C3 juvenile stage was the highest （34%） for the artificial substrate, the lowest （24%） for the shell substrate, and intermediate （27%） for the rock substrate. No significant differences were found in the wet weight and carapace width （P〉0.05） among these three treatments, although the crabs were reared in the natural shell substrate, were heavier, （4.1±0.3 mg） than those reared in the natural rock （3.9±0.1 mg）, and artificial substrates （3.8±0.7 mg） and crabs reared in the natural rock substrate were larger （1.8±0.2 mm） than those reared in the natural shell （1.7±0.2 mm）, and the same as those in the artificial substrates （1.8±0.2 mm）. These results may be due to the short length of the experiment relative to the life cycle of the species. Further research is needed to understand the optimal environmental conditions for juvenile crabs and determine how their crucial habitats, which may be easily disturbed by human activities, can be conserved.展开更多
文摘Understanding settlement tendencies and substrate preference is essential for king crab stock enhancement because structurally complex habitats provide red king crab juveniles with shelter and protect them from predation and cannibalism during critical stages of their lives. The growth and survival rates of juvenile red king crab （Paralithodes carntschaticus） from the first juvenile instar stage after settlement from the free-swimming glaucothoe （stage C 1）, to the third juvenile instar （stage C3）, that were reared in aquaria with natural rock, shell, and artificial substrate from June 8 to July 15, 2008 at the Alutiiq Pride Shellfish Hatchery in Seward Alaska were evaluated. The percent of crabs surviving to the C3 juvenile stage was the highest （34%） for the artificial substrate, the lowest （24%） for the shell substrate, and intermediate （27%） for the rock substrate. No significant differences were found in the wet weight and carapace width （P〉0.05） among these three treatments, although the crabs were reared in the natural shell substrate, were heavier, （4.1±0.3 mg） than those reared in the natural rock （3.9±0.1 mg）, and artificial substrates （3.8±0.7 mg） and crabs reared in the natural rock substrate were larger （1.8±0.2 mm） than those reared in the natural shell （1.7±0.2 mm）, and the same as those in the artificial substrates （1.8±0.2 mm）. These results may be due to the short length of the experiment relative to the life cycle of the species. Further research is needed to understand the optimal environmental conditions for juvenile crabs and determine how their crucial habitats, which may be easily disturbed by human activities, can be conserved.
