There are dozens of species of skates. According to the Florida Museum of Natural History, the common skate is the largest skate species - it can reach over 8 feet in length. At only about 30 inches, the starry skate is the smallest skate species.
Like stingrays, skates have a long, whip-like tail and breathe through spiracles. Breathing through spiracles allows the skate to rest on the ocean bottom and get oxygenated water through openings in their head, rather than breathing in water and sand from the ocean bottom. Skates may also have a prominent dorsal fin (or two fins) near the end of their tail, while rays usually do not.
While many fish propel themselves by flexing their bodies and using their tail, skates move by flapping their winglike pectoral fins.
Skates are a type of cartilaginous fish. They are classified in the order Rajiformes, which contains a dozen families, including the families Anacanthobatidae and Rajidae, which include skates and smooth skates.
Habitat and Distribution:
Reproduction is another way that skates differ from rays. Skates bear their young in eggs, while rays bear live young.
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' - and then are deposited onto the ocean floor. These mermaids purses sometimes wash up on beaches. The egg cases may sit on the ocean floor, or attach to seaweeds.
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:
Unlike stingrays, skates do not have a stinging barb on their tail, and are harmless to humans.
Skates are commercially harvested - most often using otter trawls - for their wings, which are considered tasty (Skate Wing With Butter, anyone?). The flesh of a skate's wing is said to be similar to the taste and texture of scallops.Skate wings have also been used for lobster bait, and to make fish meal and pet food.
In addition to commercial fisheries, skates 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 in the U.S. to protect skate populations through methods such as fishing trip limits, and possession prohibitions.
Below are some examples of skate species found in the U.S.:
- Barndoor Skate (Dipturus laevis)
- Big Skate (Raja binoculata)
- Longnose Skate (Raja rhina)
- Thorny Skate (Amblyraja radiata)
- Winter Skate (Leucoraja ocellata)
- Little Skate (Leucoraja erinacea)
- Bester, Cathleen. Ray and Skate Basics (Online). Florida Museum of Natural History: Icthyology. Accessed September 12, 2011.
- Canadian Shark Research Lab. 2007. Skates and Rays of Atlantic Canada: Reproduction. Canadian Shark Research Lab. Accessed September 12, 2011.
- Coulombe, Deborah A. 1984. The Seaside Naturalist. Simon & Schuster.
- Sosebee, Kathy. Skates - Status of Fishery Resources off the Northeastern US. NOAA NEFSC - Resource Evaluation and Assessment Division. Accessed September 12, 2011.
- World Register of Marine Species (WoRMS). WoRMS Taxon List. Accessed September 10, 2011.