Crayfish

Crayfish are crustaceans which can be regarded as the freshwater counterparts of the marine lobster. Those in the northern hemisphere belong to the family Astacidae, those in the southern hemisphere to the family Parastacidae. The word may also be used to describe the spiny lobster so that one is on safest ground if you describe the subjects of this entry as ‘freshwater crayfish’. The word crawfish is an American variation from the 19th century.

The name ‘crayfish’ prompted remarks by the English zoologist T. H. Huxley (1880):

It might be readily supposed that the word ‘cray’ had a meaning of its own and qualified the substantive ‘fish’—as ‘jelly’ and ‘cod’ in ‘jellyfish’ and ‘codfish’. But this certainly is not the case. The old English method of writing the word was ‘crevis’ or ‘crevice’, and the ‘cray’ is simply a phonetic spelling of the syllable ‘cre’ in which the ‘e’ was formerly pronounced as all the world, except ourselves, now pronounce that vowel. While ‘fish’ is the ‘vis’ insensibly modified to suit our knowledge of the thing as an aquatic animal.