Second Occurrence and Persistence of the Amphipod Orchestia bottœ M. Edwards in Britain

Abstract

THE amphipod Orchestia bottœ" M. Edwards was first recorded in Britain by Gordon¹, who found it on the banks of the Thames at Richmond in 1942. This species, from the Mediterranean area, appears to be spreading and invading the freshwater systems of Europe. Dr. Gordon quotes records of its being taken in France (Cambrai, Nancy), Holland (80 km.from the sea), Belgium and Germany. The object of this note is to record that in July 1946 we found it in large numbers, adult and very young, in the damp roots of grass just above the water on the right bank of the Thames at Oxford., about half-way between Folly Bridge and Ifney Bridge ; this is 92 miles upstream from the first lock (Teddington). In July 1947, one of us (A.J.C.) found it again in the same spot, still quite abundant though perhaps less so than in 1946. The severity of the spring had not apparently affected it.