Meeting Abstract

88.2  Friday, Jan. 7  Reproductive indices of male snow crab Chionoecetes opilio from the eastern Bering Sea ZALESKI, M.A.F.*; TAMONE, S.L.; Univ. of Alaska Fairbanks; Univ. of Alaska Southeast mfox30@alaska.edu

Research regarding the reproductive biology of snow crabs Chionoecetes opilio, a commercially important species in the eastern Bering Sea, is predominantly focused on females with little known about male physiology. A management assumption is each male mates once before being harvested, however newly molted males may not have restored sufficient spermatophores to actively participate in reproduction. Male snow crab terminally molt, shown through an allometric change in chela height compared to carapace width. Terminally-molted males are called “large-claw” (LC) while males that will molt at least once more are called “small-claw” (SC). Newly molted males are referred to as “new-shell” while males that have not molted in at least one year are considered “old-shell”. Molting and reproduction are regulated hormonally, in part, by ecdysteroids (molting) and methyl farnesoate (MF, mating). High levels of MF correlate with reproductively active male crustaceans; we propose MF levels will be lower in newly molted snow crabs. The purpose of this study is to measure reproductive hormones, structures, and behaviors in SC and LC males, comparing new- and old-shell males. Hemolymph was sampled for ecdysteroid and MF analysis. Gonadosomatic index (GSI) was measured as a proxy for reproductive fitness by dividing gonad weight by the whole crab wet weight. In both SC and LC males, GSI was significantly lower in new-shell males compared to old-shell males (ANCOVA, p<0.05). With lower reproductive capacity, recently molted crabs may be harvested before contributing reproductively to the population.