Little Skate (Leucoraja erinacea)
Alternate common names: Common Skate, Raja
Color: Light brown to gray on the back, paler toward the edges of the pectoral fins, white or grey belly; will change color to match bottom shading.
Size: Averages 16 to 20 inches long, 8 to 16 inches wide.
Habitat: Shallow water, sandy and muddy bottoms.
Seasonal appearance: Spring, summer, fall.
Like rays and sharks, skates belong to a family called elasmobranchs, which includes all fish with a skeleton made entirely of cartilage. One of the more common species of skate found in Rhode Island is the little skate. Its body is shaped like a flattened, rounded triangle and is well adapted for life on the bottom of the Bay. The little skate is armored with sharp spines along the back and tail that are used as a defensive measure of protection. Females have more spines than the males. Males are distinguished by two long claspers along their pelvic fins, which they use to hold onto the females and transmit sperm. The little skate has many rows of blunt teeth, resembling sandpaper, that help grind food between two well-developed jaw plates.
Life History and Behavior
Unlike bony fish, little skates lack a mechanism to pump oxygenated water over their gills. Because skates spend most of their lives on the bottom, they breathe through specialized organs called spiracles, which are slit-like openings near their eyes. Water is taken in through the spiracles, passes over the gills, and then leaves the body through five pairs of gill slits underneath the body.
Little skates feed on a diverse diet of shellfish, crabs, sea squirts, worms, amphipods, squid, and small fish. Little skates copulate many times in a year. The female lays two large eggs that develop inside a capsule, or egg case, which is often attached to seaweed. The empty black capsules wash ashore after the young have hatched. Resembling square coin purses with prongs at each corner, the capsules are commonly called "mermaid's purses."
Adapted from The Uncommon Guide to Common Life on Narragansett Bay. Save The Bay, 1998.