The biology of Gammarus (Crustacea, Amphipoda) in the northwestern Atlantic. XI. Comparison and discussion

• 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 1975
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; North Pole
• Online Access: http://dx.doi.org/10.1139/z75-131; http://www.nrcresearchpress.com/doi/pdf/10.1139/z75-131

Available data on some aspects of the biology of 10 species of Gammarus are summarized and compared. It is concluded that the main adaptation allowing these species to occupy their extensive geographic range from the North Pole to the Gulf of Mexico is variation in body size. The large size of northern species (G. wilkitzkii and G. setosus) results in the production of a single, large, well-timed brood, which is released within the short period of optimum conditions. The medium-sized species (G. oceanicus, G. duebeni, G. finmarchicus, and G. obtusatus) produce several medium-sized broods spread through the longer optimum season. The small species (G. lawrencianus, G. tigrinus, G. stoerensis, and G. mucronatus) can produce a large number of small broods per female and also mature second generations in the much longer and warmer optimum season characteristic of the southern environment.