DISTRIBUTION OF THE CRAYFISH IN BRITISH ISLES 349
The Nomenclature, Bionomics and Distribution of
the Crayfish, Austropotambius pallipes (Lereboullet)
(Crustacea, Astacidae) in the British Isles
W. Thomas and Dr R. Ingle
University of London, Goldsmith's College
Introduction
The freshwater crayfish occurring in the British Isles has
been called variously, Cancer astacus by Pennant (1777),
Astacus fluviatilis by Bell (1853), Potamobius astacus by Leach
(1875), Potamobius pallipes by Duffield (1933) and Austropotamo-
bius (Atlantoastacus) pallipes pallipes by Bott (1950).
All these names refer to the only crayfish species indigenous
to the British Isles and distributed in rivers and lakes throughout
England, Wales and Ireland, but apparently absent from Scot-
land. The species also occurs in France, Germany and Switzer-
land, (Bott, 1950).
Duffield (1939) however, noted that crayfish from Europe
were introduced into rivers in Oxfordshire early in this century,
although he did not mention the particular species that was in-
troduced. Davies (1964) stated that in recent years imported
specimens of Astacus fluviatilis had colonised some rivers in
southern England. Davies was probably referring to Astacus
astacus (Linnaeus) but as yet we have failed to obtain samples of
this species from any British river.
The literature contains numerous references to our native
crayfish, chiefly to record the occurrence of the species, but none
refer to the breeding cycle and growth of crayfishes in British
rivers. There is only one account of the biology of A. pallipes
in German rivers (Smolian 1925). In addition the nomenclature
of this species is still in an unsatisfactory state.
We present here our views on the nomenclature of our native
crayfish, an account of a short bionomic study, and a summary
of the distribution of the species in the British Isles.
Nomenclature
In 1963 we had occasion to check the identification of cray-
fishes occurring in the River Darent, Kent. For this purpose we
used the keys and diagnoses of the European species of the family
Astacidae given by Bott (1950). We had difficulty in identifying
our specimens with Bott's figures and photographs of the species
that he designated as Austropotamobius (Atlantoastacus) pallipes
pallipes (Lereboullet) and listed as the only species occurring in