Effect of temperature on growth and maturity of the king crabs <i>Paralithodes brevipes</i> and <i>P. camtschaticus</i> in the laboratory

Abstract

The effect of temperature on growth and maturity was studied for the king crabs Paralithodes brevipes (Pb) and P. camtschaticus (Pc) in the laboratory. Molting and growth were examined individually in cultured first instar juveniles of Pb and Pc and in 2 and 3 y-old Pb collected in the wild (wild Pb). Crabs were fed mussels daily. Two temperature regimes were used, ambient (AT: -1 to 17°C) and controlled (CT: +11 to 13°C). After 4 y, Pb had reached instars 17-19 (71mm carapace length [CL], 330g) at AT, and instars 22-23 (95mm CL, 770g) at CT. Pc had reached instars 18-19 (82mm CL, 380g) at AT, and instars 20-21 (109mm CL, 1050g) at CT. Female 4 y-old Pc cultured at CT spawned after mating with 4 y males. Female Pb cultured at CT were not mature at 4 y although 4 y males did mate with 6 y females (wild Pb cultured from 2 to 6 y at AT). Thus, the growth pattern was similar between Pb and Pc, but CT had different effects on the maturation schedules of the females of the two species. At AT, no crabs were mature at 4 y.