MEPS 323:213-222 (2006)  -  doi:10.3354/meps323213

Seasonal timing and duration of brachyuran larvae in a high-latitude fjord

Jennifer L. Fisher*

Moss Landing Marine Laboratories, 8272 Moss Landing Road, Moss Landing, California 95039, USA Present address: Bodega Marine Laboratory, University of California at Davis, PO Box 247, Bodega Bay, California 94923, USA

ABSTRACT: The present study describes the seasonal distribution and abundance of brachyuran crab larvae from 5 families in lower Glacier Bay (SE Alaska, USA), and is one of the few field studies describing the entire pelagic phase of brachyuran larvae in Alaska. The larvae of most brachyuran species in Glacier Bay exhibited a highly seasonal pattern of abundance, which when first observed coincided with the onset of oceanographic conditions favorable to survival (high water temperature and abundant food supply). During May, larval abundance of Cancer magister increased by 63% relative to the first sampling date, that of C. oregonensis by 92%, Fabia subquadrata by 69%, Pugettia spp. by 73%, and Majidae by 77%. The seasonal timing and larval duration of C. magister and 4 other species in Glacier Bay were compared with the same species at lower latitudes to substantiate the hypothesis that larval release time and duration are later and longer, respectively, with increasing latitude. The initial occurrence of zoeae is delayed by 3 to 4 mo relative to published release times in California, Oregon and Washington for these species. Further, the pelagic larval duration for C. magister is approximately 30 d longer in SE Alaska than published larval durations in lower latitudes, suggesting that both these phenomena are a function of the cool water temperatures found in the former region.

KEY WORDS: Larval duration · Timing · High latitude · Cancer magister · Cancer oregonensis · Larvae · Fjord

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