The biology of Gammarus (Crustacea, Amphipoda) in the northwestern Atlantic. IV. Gammarus lawrencianus Bousfield

• Published in: Canadian Journal of Zoology
• Main Authors: Steele, D. H., Steele, V. J.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1970
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Newfoundland
• Online Access: http://dx.doi.org/10.1139/z70-215; http://www.nrcresearchpress.com/doi/pdf/10.1139/z70-215

Gammarus lawrencianus is an endemic estuarine species of the northwestern Atlantic, found from Labrador south to the Gulf of Maine. Fifty percent maturity for the females occurs at 5.25 mm at Holyrood, Newfoundland, and at 4.4 mm at St. Andrews, N.B. In Newfoundland, females produce a series of broods between March and October, at which time they enter the resting stage. The oogonia begin to enlarge in January but are not released into the brood pouch until March. The young hatched in the spring mature during the summer and may produce several broods before October. The older generation disappears in the summer. The population rises quickly to a peak in August or September in the river water but declines rapidly in early winter. Only in the bottom of pools and in the barrachois pond do specimens apparently survive until spring.