The Coastrange sculpin (Cottus aleuticus) is a freshwater sculpin of the genus Cottus. They are commonly found near the ocean in western North America, namely Canada and the United States. It is also known as the Aleutian sculpin.
The Coastrange sculpin can be distinguished from other species due to several unique traits. It only has one pore under its chin, no palatine teeth, and no distinct gap between the two dorsal fins. Adults can grow to be as long as 17 cm, although their average length is only 6 cm. Their maximum reported life span is 8 years. Breeding female Coastrange sculpins are generally larger than males. Breeding males are almost entirely black with a tiny bit of orange trim on the first dorsal fin.
The Coastrange sculpin is found exclusively along the Pacific coast of North America. They range from Bristol bay and the Aleutian islands of Alaska, south to Santa Barbara County, California, Though they can also be found sporadically in streams as far south as Mendocino County There are also isolated populations in Alaska's Kobuk river, Lake Washington of Washington state, and British Columbia's Cultus Lake.
Living mostly in rivers and streams, Coastrange sculpins are found in riffles and glides with coarse or cobble stone bottoms from.20m to 1.0m in depth. At night, they move into shallower, calmer waters on the edges of rivers. It occurs in virtually the same habitats as the Prickly sculpin (Cottus asper) and the two species encounter one another and interact regularly. They also tend to encounter salmon and the Three-spined stickleback as well.
Coastrange sculpins are solitary, nocturnal carnivores and known to eat nymphs and larvae of insects such as mayflies, stoneflies, and chironomids (and other aquatic invertebrates). They are also known to eat the eggs and fry of the pink and chum salmon. Their larvae are free swimming/floating and feed mostly on plankton, however they become bottom dwellers after they transform and eat the same diet as the adults, except that they take smaller organisms as prey. They are also eaten by coastal cutthroat trout, coho and sockeye salmon, and Dolly Varden trout.
