Variation in Body Size of Two Species of Supralittoral Talitrids (Amphipoda, Talitroidea) from the Gulf of Mexico and Atlantic Coasts of North America

Abstract

AbstractPopulations of Platorchestia platensis (Krøyer, 1845) and Orchestia grillus Bosc, 1802 (Amphipoda, Talitroidea) show variations in body size throughout their range in the Gulf of Mexico and along the Atlantic coast of North America. For each species we describe an intraspecific correlation between median body size and degrees of latitude north, such that in populations progressively further north from the equator, the median body size becomes larger. This growth and development pattern is consistent with the metabolic theory of ecology and appears to be general among Talitridae, with a few exceptions.