Phenology in Calanus funmarchicus; hypotheses about control mechanisms

• Main Authors: Miller, Charles B., Cowles, Timothy J., Wiebe, Peter H., Copley, Nancy J., Grigg, Helen
• Format: Article in Journal/Newspaper
• Language: English; unknown
• Published: Inter Research
• Subjects: Calanus finmarchicus; North Atlantic
• Online Access: https://ir.library.oregonstate.edu/concern/articles/8910jw12x

Calanus finmarchicus (Gunnerus) stratify narrowly near 500 m depth during their fifth copepodite resting phase in North Atlantic Slope Water off southern New England, USA. They probably achieve this by migration to a specific, daytime isolume. Photoperiod information provided by light intensity at depth could serve as a cure for termination of the resting phase. Population data on tooth formation and gonad growth show that the resting stock prepares for termination in late winter and matures in February-March. Photoperiods are lengthening throughout that seasonal interval, and might cue arousal. An endogenous, 'long-range' timer that cues arousal after an interval of rest is another possible mechanism.