Origins
Origins
The crayfish are of the variety Pacifastacus Leniuculus, commonly known in the U.K. as the Signal Crayfish. They are trapped by us from clear waters all over the U.K. e.g. gravel pits and rivers. The fish are held in purging tanks for one week prior to export or delivery.
Up to 30cm in length from tip of rostrum to end of telson. More often 15cm. The rostrum is smooth and more or less parallel. Apex very pointed with prominent shoulders. Central ridge smooth. The body is smooth, generally bluish-brown to reddish brown in colour. Two pairs of post-orbital ridges.
No spines on shoulders of carapace behind cervical groove. The claws are smooth on both surfaces. Underside red in colour. Single tubercle (small nodule) on fixed side claw. White-turquoise patch on top of junction of claw (hence common name - signal). An aggressive, invasive species. Will burrow extensively into suitable substrates. Lives in similar habitats to native species. Distribution widespread, particularly in the south of England.