Effects of temperature on size-at-terminal molt and molting frequency in snow crab Chionoecetes opilio from two Canadian Atlantic ecosystems

Marine Ecology Progress Series

Mikio Moriyasu¹  Earl G. Dawe¹  Darrell R. Mullowney¹  Elmer Wade¹ 

关键词: Snow crab;    Terminal molt;    Molting frequency;    Size;    Temperature;    Atlantic Canada;   

DOI  :  10.3354/meps09793

学科分类：海洋学与技术

来源: Inter-Research

【 摘 要 】

ABSTRACT: The effect of temperature on molting frequency and size-at-terminal molt of the snow crab Chionoecetes opilio was investigated and compared between 2 Canadian Atlantic ecosystems based on spring and summer surveys. We found that the size-at-terminal molt was directly related to temperature but that the effect of temperature was much clearer and occurred at smaller sizes for females than for males. By focusing on recently molted (new-shelled) crabs, we showed that size-at-terminal molt is conditioned by temperature over a variable number of instars and intermolt periods leading up to the terminal molt. Crabs of both sexes larger than about 50 mm carapace width (CW), on annual molting schedules, sometimes skipped a molt. The frequency of skip-molting differed between the areas and sexes, and was directly related to size and inversely related to temperature. We develop a hypothesis to explain the relationships of terminal size with temperature and molting frequency that is consistent with life-history theory and snow crab bioenergetics and considers differences between the sexes. The implications to natural mortality and recruitment to fisheries are also discussed.

【 授权许可】

Unknown