Photo: Astacoides, Creative Commons
Terminal Creek
Signal Crayfish
(Pacifastacuc leniuscuslus)
On this Page
by Bob Turner
Until I stuck my facemask into Terminal Creek, I had no idea we had crayfish on Bowen Island.
But there it was, a reddish brown fresh-water cousin of the lobster, crawling out from under a rock, claws held high. Signal crayfish are BC’s only native crayfish. They range from southern BC to northern California and east to the Rockies.
Crayfish are fascinating crustaceans, cousins of shrimp, prawns and crabs. They live inside hard exoskeletons that they shed and rebuild (molt) as they grow, leaving them vulnerable during the molting process. They are omnivores, eating a variety of foods such as decaying roots, leaves, stream bottom insects, smaller crayfish, and fish.
Signal crayfish are solitary animals, living alone in crevices or in burrows under rocks. They breathe through feather-like gills, have compound eyes on the ends of long stalks, feel their way along with antennae, walk on their many feet, but can dart quickly if alarmed, with a flick of their tail.
Adult crayfish are on the lookout for predatory mink and otter, while juvenile crayfish can be prey to larger crayfish, merganser ducks, and larger trout. The presence of crayfish in Terminal Creek is a sign that the water quality is good, as crayfish are very sensitive to pollution.