Skate Characteristics and Information

Skates are a type of cartilaginous fish—fishes with skeletons made of cartilage, rather than bone—that are characterized by flat bodies and wing-like pectoral fins attached to their heads. (If you can picture a stingray, you know basically what a skate looks like.) There are dozens of species of skates. Skates live throughout the world, spending most of their time on the ocean bottom. They have strong teeth and jaws, allowing them to easily crush shells and feed on shellfish, worms, and crabs. According to the Florida Museum of Natural History, the common skate—which can reach over eight feet in length—is the largest skate species, while at only about 30 inches, the starry skate is the smallest skate species.

How to Tell a Skate From a Ray

Like stingrays, skates have a long, whip-like tail and breathe through spiracles, which allows the skate to rest on the ocean bottom and receive oxygenated water through openings in their heads, rather than breathing in water and sand from the ocean bottom.

While many fish propel themselves by flexing their bodies and using their tails, skates move by flapping their wing-like pectoral fins. Skates may also have a prominent dorsal fin (or two fins) near the end of their tails; rays usually do not, and unlike stingrays, skates lack venomous spines in their tails.

Skate Reproduction

Reproduction is another way that skates differ from rays. Skates are oviparous, bearing their offspring in eggs, while rays are ovoviviparous, meaning their offspring, while beginning as eggs, remain in the mother's body after hatching and continue to mature until they're eventually born live.

Skates mate at the same nursery grounds each year. Male skates have claspers that they use to transmit sperm to the female, and eggs are fertilized internally. The eggs develop into a capsule called an egg case—or more commonly, a "mermaid's purse"—which are deposited on the ocean floor.

The egg cases either remain where they're deposited or attach to seaweed, although they sometimes wash up on beaches and are easily recognized by their distinctive appearance (a small, flat, near-rectangular "headless animal" with its arms and legs outstretched). Inside the egg case, a yolk nourishes the embryos. The young may remain in the egg case for up to 15 months, and then hatch looking like miniature adult skates.

Conservation and Human Uses

Skates are harmless to humans. They are commercially harvested for their wings, which are considered a delicacy, said to be similar in taste and texture to scallops. Skate wings can also be used for lobster bait, and to make fish meal and pet food.

Skates are usually harvested using otter trawls. In addition to commercial fisheries, they may also be caught as bycatch. Some U.S. skate species, such as the thorny skate, are considered overfished, and management plans are in place to protect their populations through methods such as fishing trip limits, and possession prohibitions.

Sources

• Bester, Cathleen. "Ray and Skate Basics". Florida Museum of Natural History: Ichthyology. 
• "Skates and Rays of Atlantic Canada: Reproduction". Canadian Shark Research Lab. 2007
• Coulombe, Deborah A. "The Seaside Naturalist". Simon & Schuster. 1984
• Sosebee, Kathy. "Skates—Status of Fishery Resources off the Northeastern US". NOAA NEFSC—Resource Evaluation and Assessment Division.
• World Register of Marine Species (WoRMS). WoRMS Taxon List.