Detailed studies of the vertical distribution and migration of the micronekton, plankton and sonic scattering layers in an oceanic environment off Fuertaventura in the Canary Islands were made from R.R.S. ‘Discovery’ during September to December 1965. A general account, including a statement of the objectives of the cruise, has been given by Currie, Boden & Kampa (1969). Foxton (1969) has described the biological sampling methods and techniques utilized. Results of sonic scattering investigations have been published by Blaxter & Currie (1967) and Boden & Kampa (1967). The present study deals only with the pelagic amphipods, and forms a contribution to a series (Angel, 1969; Clarke, 1969b; Baker, 1970; Foxton, 1970a, b; Badcock, 1970; Roe, 1972a, b, c, d; Pugh, 1974) dealing with the distribution and migration of the major taxa sampled during the investigation. An objective summary of the plankton data utilizing factor analysis and cluster analysis has been provided by Angel & Fasham (1973, 1974).