Spotted Ratfish
Spotted ratfish
Scientific Name Hydrolagus colliei
Conservation Status Least Concern
Family Chordata
Habitat Northeast Pacific rim
Food Crustaceans and bivalves

The spotted ratfish, Hydrolagus colliei, is a chimaera found in the north-eastern Pacific Ocean. Often seen by divers at night in the Pacific Northwest, this harmless shark relative gets its characteristic name from a pointed rat-like tail. The ratfish lays leathery egg cases on the bottom of sandy/mud areas which are often mistaken by divers as something inanimate. While mainly a deep-water species, it occurs at shallower depths in the northern part of its range.

The spotted ratfish can be found in the north-eastern Pacific Ocean. They can most commonly be found between the Pacific Northwest. The range of depths in which this fish is found extends from 0 to 3,000 feet (0 to 910 m) below sea level. Near 115° N. longitude and further north, the spotted ratfish lives close to the shore. On the southern end of their range, they live in deeper waters. Ratfish tend to move closer to shallow water during the spring and autumn, then to deeper water in summer and winter. Spotted ratfish can most commonly be found living near the bottom of sand, mud or rocky reefs of the ocean floor. Unlike most of its relatives which are entirely restricted to deep waters, the spotted ratfish has been held in public aquaria.

The spotted ratfish swims slowly above the seafloor in search for food. Location of food is done by smell. Spotted ratfish are particularly drawn to crunchy foods like crabs and clams. Besides crabs and clams, the spotted ratfish also feeds on shrimp, worms, small fish, small crustaceans, and sea stars. Species known to predate on the spotted ratfish include soupfin sharks, dogfish sharks, Pacific halibut, and Pigeon Guillemots. Their usual hunting period is at nighttime, when they move to shallow water to feed.