Rosette rays
| Rosette rays | ||||||||||||
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Rosette ray ( Leucoraja garmani ) |
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Leucoraja garmani | ||||||||||||
| ( Whitley , 1939) |
The rosette ray ( Leucoraja garmani ) is a species of the family of real rays (Rajidae), which occurs in the northwestern Atlantic off the eastern US coast. It is a deep sea ray and a fairly small representative of this genus.
features
This ray has a blunt snout and rounded pectoral fins, the upper edges are slightly arched forward. It is pale brown and has different shades and dark spots. These spots are usually arranged in six rosettes around a central spot and are dark brown or black. These spots can be found on their shoulders and pectoral fins, and it is from them that this ray got its name. The spots can be used to distinguish them from other species. The ventral side is white or pale yellow.
They grow to a maximum of 26 centimeters wide and their tail is 17.5 centimeters long. Overall, they are about 45 centimeters long. With a length of approx. 40.5 centimeters, males reach sexual maturity, while females reach sexual maturity a little earlier.
They have small spines on their snouts, around their eyes, on their tail and shoulders. Young animals have a rough skin with small spines that are lost over time.
The upper jaw of the rosette ray contains 46 to 52 rows of teeth, the lower jaw a few fewer. Older males have sharper teeth than females.
distribution
The rosette ray can be found along the US east coast, from Nantucket in Massachusetts to Dry Tortugas south of Florida . However, little information is currently available on the population south of Cape Hatteras , South Carolina .
Way of life
The rosette ray can be found above sandy or muddy ground at depths of approx. 33 to 530 meters, most often between 74 and 274 meters. Juvenile specimens that are less than 18 inches long are found along the outer continental shelf throughout the year. The preferred water temperature is between 5 and 15 ° C.
The food is similar to the other species of rays found in this environment. It feeds on invertebrates such as shrimp, crayfish, crab, octopus, and small fish. This ray is hunted by larger fish including sharks. Very little is known about parasites that attack this species.
Reproduction
This type of ray lays eggs . Amber-colored capsule-like eggs contain embryos. These have small stiff horns at each of the four corners with which they are attached to sand or mud. They are very small with a length of approx. 3.4 to 4.3 centimeters and a width of approx. 2.6 to 3 centimeters. Because these eggs are so small they can be distinguished from those of the other species of rays. These rays reproduce all year round, with more eggs appearing in the summer months.
Danger
This species is unintentionally caught by bottom trawls as bycatch . It is used as lobster bait or its pectoral fins are sold. There is no evidence of directed fishing in this way. Currently this species is not considered overexploited and there are no major threats to Leucoraja garmani . That is why the rosette ray is classified as not endangered by the IUCN .
supporting documents
- ↑ Rosette Ray on Fishbase.org (English)
- ↑ a b c d Cathleen Bester: Rosette Skate. Florida Museum of Natural History, accessed August 10, 2017 .
- ↑ a b c d Leucoraja garmani in the Red List of Threatened Species of the IUCN 2017-1. Posted by: Gedamke, T., 2008-12-01.
