The biology of Gammarus (Crustacea, Amphipoda) in the northwestern Atlantic. II. Gammarus setosus Dementieva

• Published in: Canadian Journal of Zoology
• Main Authors: Steele, V. J., Steele, D. H.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1970
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Northwest Atlantic
• Online Access: http://dx.doi.org/10.1139/z70-124; http://www.nrcresearchpress.com/doi/pdf/10.1139/z70-124

Gammarus setosus is a circumpolar species found as far south as the Bay of Fundy region in the northwest Atlantic. Under laboratory conditions (3 °C) sexual maturity is reached in the 13th molt, at 14 mm in the males and at 12 mm in the females. In the field 50%, maturity is attained at 13.5 mm in the females. Mature females annually produce a single autumn brood, which is released in late winter or early spring. They then enter an obligatory resting period. In the laboratory at 12 °C they can have more than one brood annually. Fecundity increases with the size of the Female. The large size at maturity, continued growth, and long life with resulting high fecundity partially compensate for the production of but one brood per year.