Substrate Selection by Corophium Species: The Particle Size of Substrates

Marine invertebrates which live in sand or mud are often limited to sediments or 'substrates' having a particular range of particle size (Pirrie, Bruce & Moore 1932; Thamdrup 1935; Yonge 1953; Steven 1953; Anon. 1957; Wieser 1959; Aldrich 1961). The amphipods Corophium arenarium Crawford and C. volutator (Pallas) are no exception to this rule: the former lives in sand and the latter in mud (Hart 1930; Thamdrup 1935; Crawford 1937; Beanland 1940; Watkin 1941; Holme 1949; Segerstrale 1959; Stock & de Vos 1960; Gee 1961; Anon. 1963). Both species inhabit permanent U-shaped burrows. The experiments reported below are concerned with why the two species are found in markedly different substrates. They form part of a series which were designed to elucidate the factors affecting substrate selection by C. arenarium and C. volutator (Meadows 1964a, b). Their subject is the influence of particle size. Other characteristics of the substrate which Corophium react to include substrate depth (Meadows 1964b), and the nature of naturally occurring films on substrate particles (Meadows 1964a).