Friday, December 27, 2019

Winter Skate Characteristics and Information

The winter skate (Leucoraja ocellata)  is a fish - a type of  cartilaginous fish that has wing-like pectoral fins  and a flat body. Skates resemble a stingray, but have a thicker tail that doesnt have any stinging barbs. The winter skate is one of dozens of species of skates.  . Description: Skates are a diamond-shaped fish that spend most of their time on the ocean bottom. Their gills are on their ventral side, so they breath through spiracles  on their dorsal side. Through the spiracles, they receive oxygenated water. Winter skates have a rounded appearance, with a blunt snout. They look similar to little skates (Leucoraja erinacea).  Winter skates can grow to about 41 inches in length and up to 15 pounds in weight. On their dorsal side, they are light brown with dark spots, and have a lighter, translucent patch on each side of their snout on front of the eyes.   Their ventral side is light with brown blotches. Winter skates have 72-110 teeth in each jaw. Stingrays can protect themselves with stinging barbs on their tail. Skates do not have tail barbs, but have thorns in various places on their body. On young skates, these thorns are on their shoulders, near their eyes and snout, along the middle of their disc and along their tail. Mature females have large thorns on the posterior edge of their dorsal fins and spines on their tail, along the edges of their disk and near their eyes and snout.   So although skates cannot sting humans, they must be handled with care to prevent being punctured by the thorns. Classification: Kingdom: Animalia Phylum: Chordata Class: Elasmobranchii Order: Rajiformes Family: Rajidae Genus:  Leucoraja Species:  ocellata Feeding: Winter skates are nocturnal, so they are more active at night than during the day.   Preferred prey include polychaetes, amphipods, isopods, bivalves, fish, crustaceans and squid.   Habitat and Distribution: Winter skates are found in the North Atlantic Ocean from Newfoundland, Canada to South Carolina, U.S., on sand or gravel bottoms in waters up to 300 feet deep. Reproduction: Winter skates are sexually mature at 11-12 years. Mating occurs with the male embracing the female.It is easy to distinguish male skates from females because of the presence of claspers, which hang down from the males disk on either side of the tail. These are used  to transmit sperm to the female, and eggs are fertilized internally. The eggs develop in a capsule commonly called a mermaids purse - and then are deposited onto the ocean floor.   Once eggs are fertilized, gestation lasts for several months, during which time the young are nourished by the egg yolk.   When the young skate hatch, they are about 4-5 inches long and look like miniature adults.   The lifespan of this species is estimated at about 19 years.   Conservation and Human Uses: Winter skates are listed as endangered on the IUCN Red List. They take a long time (11-12 years) to become old enough to reproduce and produce few young at a time. Thus their population grows slowly and is vulnerable to exploitation.   Winter skates are harvested for human consumption, but are usually caught when fishermen are targeting other species.   References and Further Information: Bester, C. Winter Skate. Florida Museum of Natural History: Icthyology. Accessed February 27, 2015.Coulombe, Deborah A. 1984. The Seaside Naturalist. Simon Schuster. Kulka, D.W., Sulikowski, J. Gedamke, T. 2009.  Leucoraja ocellata. The IUCN Red List of Threatened Species. Version 2014.3.  Accessed February 27, 2015. Packer, D.B., Zetlin, C.A. and J.J. Vitaliano. Winter Skate, Leucoraja ocellata, Life History and Habitat Characteristics.  NOAA Technical Memorandum NMFS-NE-179. Accessed February 28, 2015.NOAA FishWatch. Winter Skate.  Accessed February 27, 2015.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.