Blackline Prickleback, Acantholumpenus mackayi

The blackline prickleback is one of the eight shannies that inhabit Canadian waters. Because they so closely resemble each other, their distribution is often used to distinguish them. Specifically, the blackline prickleback is found off the Arctic coast of Canada in the Beaufort Sea, south to the Bering Sea and Japan. The numbers of rays in the various fins can also be used as characteristics of identification. Its dorsal fin has 59 rays and is widest halfway down the back, while the caudal fin is rounded, and the anal fin has two spines and 41 soft rays. Otherwise, the features of this fish are typical of shannies: a long eel-like body, a heavily built head, and large fan-like pectoral fins. This species can reach a length of 70 cm. Its body is yellowish-brown with a solid black line along the base of its dorsal fin and 2 other dashed lines running along the length of its body. Its pectoral fins are orange while the roof of the mouth is black.

It has been estimated that the blackline prickleback can live for at least 16 years. Spawning likely occurs in the fall as females caught in Tuktoyaktuk Harbour, NWT, in August were nearly ripe. It has been caught at depths of no more than 60 m and ranges all the way to the shoreline. Food seems to consist of anything that will fit in its mouth and can include worms, crustaceans, young sea urchins, small clams, and snails.