The Distribution of Amphipods in the Severn Estuary and Bristol Channel

DURING the course of a biological survey of the intertidal fauna of the Severn Estuary and Bristol Channel a good deal of attention has been paid to the distribution of the abundant and widespread genus of Amphipods-Gammarus. As with all the fauna, the actual records of the 54 species of Amphipods have already been presented (Bassindale, 1941). Mr G. M. Spooner has identified all the Amphipods taken in the collections, and it was he who suggested that collections made in summer and winter might show a seasonal shift of populations. The present account deals with the commonest species (excluding sand-hoppers), but particularly with species of Gammarus and Marinogammarus. Of the Gammarus species taken, G. zaddachi is the most abundant. There are two notable absentees-G. duebeni Lilljeborg and G. chevreuxi Sexton. 2. DISTRIBUTION IN THE SEVERN ESTUARY