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

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 469:279-296 (2012) - DOI: https://doi.org/10.3354/meps09793 Effects of temperature on size-at-terminal molt and molting frequency in snow crab Chionoecetes opilio from two Canadian Atlantic ecosystems Earl G. Dawe1,*, Darrell R. Mullowney1, Mikio Moriyasu2, Elmer Wade2 1Fisheries and Oceans Canada, Northwest Atlantic Fisheries Centre, PO Box 5667, St. John’s, Newfoundland and Labrador, A1C 5X1 Canada 2Fisheries and Oceans Canada, Gulf Fisheries Centre, PO Box 5030, Moncton, New Brunswick, E1C 9B6 Canada *Email: earl.dawe@dfo-mpo.gc.ca 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. KEY WORDS: Snow crab · Terminal molt · Molting frequency · Size · Temperature · Atlantic Canada Full text in pdf format PreviousNextCite this article as: Dawe EG, Mullowney DR, Moriyasu M, Wade E (2012) Effects of temperature on size-at-terminal molt and molting frequency in snow crab Chionoecetes opilio from two Canadian Atlantic ecosystems. Mar Ecol Prog Ser 469:279-296. https://doi.org/10.3354/meps09793 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 469. Online publication date: November 26, 2012 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2012 Inter-Research.