Live specimen of C. latens for the shell selection experiment preferred the shell type which was the most abundant in the field. But the field specimen did not use the most abundant shell type. Although the intertidal and subtidal groups of C. latens used different shell types, the means of crab and shell parameters were not significantly different. In addition, the crab-shell regression lines were also not significantly different between these two C. latens groups, suggesting that they belonged to the same population. The crab-shell regression lines of subtidal groups of C. latens and C. gaimardii were not significantly different, but they preferred different shell types. It seems that competition between these two species takes place which leads to segregation of their shell utilization.

    The result of shell adequacy test showed that most crabs lived in adequate shell at least by internal volume. However, shell selection experiment proved that crabs would select larger shells if they were available. The most correlative shell parameter of intertidal C. latens, subtidal C. latens, subtidal C. gaimardii, and laboratory C. latens was shell length, shell width, shell weight, and aperture width, respectively. These results may be responded to their environmental stress or may be due to species competition. Principal component analysis of shell parameters showed that the first principal component (PC 1) had high positive correlation with each shell parameters. PC 1 may represent each size parameters efficiently, thus can explain the relationship between crab and shell parameters more concisely.