Relative Growth of Three Chionoecetes Crabs (decapoda, Majidae) in the East Sea, Korea

Snow crabs, Chionoecetes spp., are among the commercially most important species of Decapoda in the world, and proper stock assessment and management are required for their sustainable use. In the present study, morphological characteristics of three snow crabs, Chionoecetes japonicus, Chionoecetes opilio and a hybrid form exhibiting characteristics intermediate between those of the parent species, Chionoecetes japonicus/opilio, have been compared. The ratio of carapace length including rostral horn (CL(RL)) to carapace width (CW) in C. japonicus, C. opilio, and the C. japonicus/opilio hybrid was 0.973 ± 0.020, 0.983 ± 0.019, and 0.956 ± 0.019, respectively. The only significant difference in regression slope among the three crabs, was between CW and chela height (CH), indicating that at a given size, the hybrid form is the fastest in the growth of chela height in relation to carapace width. In C. japonicus and C. opilio, the relationship between CW and total weight (TW) was significantly negatively allometric, while in the hybrids, it was significantly positively allometric. This indicates that at a given size, the hybrid form is heavier than the others.