Abstract
Relative growth of the chelae of the Japanese mitten crab Eriocheir japonica during the juvenile stages was investigated by laboratory rearing. Regression of chela propodus height (CPH) on carapace width (CW) suggested that two growth phases are present in juveniles (CW<40 mm) of both sexes. These two phases are separated by an inflection at approximately 11 mm CW in both sexes. Between the first and second phases, there are significant differences in the slope and Y-intercept of the regression lines for each sex. Significant differences between sexes were not detected for the first phase, but were detected for the second phase. With the addition of data for sub-adult and adult stages a complete growth pattern of E. japonica chela could be estimated. In addition to the first phase three other phases in the males and two phases in females were observed.
