Field Identification of Five Species of Californian Beach Hoppers (Crustacea: Amphipoda)

Abstract

While studying the correlations between the distribution of five species of beach hoppers of the genus Orchestoidea and the physical and biotic factors of their sandy beach habitat, it became necessary to identify with certainty the animals collected from the many beaches sampled up and down the Californian coast. Since it was desirable tentatively to name the hoppers captured in the field, I made an effort to find characters which were easily observed on the beach and would allow such identification. As a result of my examination of many thousands of animals from over a hundred collecting localities, I evolved a recognition of the five species mainly on the basis of pigmentation patterns, elements of which are relatively consistent in spite of the many variations to be found in the total pigmentation.