Barndoor skate

The barndoor skate is one of the largest species in the Rajidae family, at five to six feet (1 1/2 to 2 meters) long and 40 pounds (18 kilograms). It can descend to the bottom in water as deep as 1,410 feet (430 meters).

Kingdom: Animalia

Phylum: Chordata

Class: Chondrichthyes

Order: Rajiformes

Family: Rajidae

Genus: Raja

Species: Laevis

It is not certain how this flat-bodied fish received its name, but one possibility may be its large, broad, diamond-shaped body with its wing-like pectoral fins. Because of its size, someone may have once said that the skate was as large as a barndoor. It is one of the largest species in the family, growing to five to six feet (1 1/2 to 2 meters) long, and almost as wide between its fin tips. An adult may weigh nearly 40 pounds (18 kilograms).

A barndoor skate has a long, fleshy, thick tail with three rows of spines running nearly its entire length. Two small dorsal fins line the back surface of the tail near the tip. The tail is able to produce a small electrical charge of four volts, but it is not known what purpose this serves. Its body and tail are brown on the back side and usually have small dark spots. The underside is white with gray patches and tiny, black pores, or openings, for mucus.

The barndoor skate has openings called spiracles behind its eyes. These are the openings with which the skate breathes when it is lying in the sand or mud. Its mouth, nostrils, and gills are on its underside. If the skate were to use these while hiding, it would breathe sand and mud. Water drawn into the spiracles passes over the gills, which remove the oxygen. The rest of the water is then pumped out through the five sets of gill openings. When the skate is swimming it is able to breathe through its mouth and nostrils.

All species of skates belong to the class of cartilaginous fish, which includes the sharks, rays, and chimaeras. These fish do not have bones in their bodies but have cartilage instead. This tissue is softer than bone but still keeps the form of the fish's bodies.

The barndoor skate lives along the eastern coast of the United States, as far north as Newfoundland and as south as Florida. Their habitat is along the continental shelf in the sandy or muddy sea bottom. They can live in depths of up to 235 fathoms, or 1,410 feet (430 meters). During the warm summer months in the south, the skate may move from shallower to deeper waters.

The diet of the barndoor skate includes mollusks, crabs, lobsters, small squid, shrimp and other crustacea, and some species of fish. It hunts during both night and day and uses its sense of smell more than its good vision to find its prey. Prey is taken either as the skate swims or by surprise as the skate buries itself beneath the sand and then grabs food within reach.

Predators are not known, except that the skate has a reputation for biting fishermen's hooks.

After mating, a female barndoor skate lays an egg case on the bottom of the ocean. The case may contain one or more babies, which take six to nine months, or maybe even a year, to hatch. The egg case is often called a sea or mermaid's purse. It is brown or blue, rectangular, and has a leather-like surface. From each corner hangs a thin strand to anchor it to a rock or weed along the bottom of the sea.

The average lifespan of a barndoor skate is between 13 and 16 years.

Barndoor skates are listed as endangered on the International Union for Conservation of Nature (IUCN). However, there are conflicting opinions in the conservation community as to whether or not the barndoor skate is actually at risk of extinction.

Bibliography

“Barndoor Skate Fact & Information Guide.” American Oceans, 6 Sept. 2023, www.americanoceans.org/species/barndoor-skate/. Accessed 30 Mar. 2024.

“Barndoor Skate.” Oceana, 23 June 2023, oceana.org/marine-life/barndoor-skate/. Accessed 30 Mar. 2024.

Basta, Jennifer. “Dipturus Laevis (Barn-Door Skate).” Animal Diversity Web, animaldiversity.org/accounts/Dipturus‗laevis/. Accessed 30 Mar. 2024.