Spotted angel shark
| Spotted angel shark | ||||||||||||
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| Squatina punctata | ||||||||||||
| Marini , 1936 |
The spotted angel shark ( Squatina punctata ) is a ground-dwelling shark found off the South American coast.
Appearance and characteristics
The spotted angel shark reaches a maximum body length of up to 90 cm. As with other angel sharks, the body is strongly flattened with very broad pectoral fins , which makes the animals look more like long rays in shape . However, the pectoral fins are clearly separated from the trunk, while in most rays they merge seamlessly into the body. They have two dorsal fins and no anal fin . The body has a dark brown back color with small, irregular black spots. The ventral side is white. There may be white-bordered eye spots . Enlarged short thorns are located in small groups in the snout area and in the area of the eyes, on the back there is a single row of small dorsal spines.
The eyes are on the top of the head with a broad, concave surface between the eyes, the mouth is terminal, the outer nostrils are provided with short barbels . The injection holes are large. The number of lateral, lower gill openings is five. The nasal flaps are only slightly fringed or smoothly edged, the barbels are not fingered.
distribution
The distribution area of the spotted angel shark is in the western Atlantic in the coastal area of South America off Brazil , Uruguay and Argentina .
It lives on the outer edge of the continental shelf at depths between 10 and 80 meters.
Way of life
Little data is available on the biology of this shark. He feeds mainly on small bony fish, cephalopods and crabs . Like all angel sharks, it is ovoviviparous - the eggs are hatched in the mother before the young are born alive. For birth, the females go to shallower areas near the coast in spring. The young animals are three to eight centimeters long at birth and stay in shallow water for about a year. The sharks reach sexual maturity at a body length of around 70 to 80 centimeters.
Danger
The International Union for Conservation of Nature (IUCN) classifies this shark as endangered ("Endangered"). As with other species on the South American coast, the classification was based on the comparatively low reproduction rate and the risk of overfishing caused by the use of ground and trawl nets in the range of the species. Angel sharks are heavily fished in southern Brazil in particular, so a sharp decline has been recorded here in particular: The peak of angel shark fishing (also affects the Argentine angel shark ( S. argentina ) and the Guggenheim angel shark ( S. guggenheim )) was between 1986 and 1989 and in 1993 at around 2,000 tons per year, before falling to 900 tons by 2003. In addition, the shark is a common bycatch species in commercial fisheries, which primarily aim to catch the anglerfish species Lophius gastrophysus . Research catches from 1986/87 and 2001/02 could show that the stocks of the Guggenheim angel shark have decreased by 85%. In addition, the sharks seem to get their young in special shallow water areas below 30 meters deep, where the fishing pressure is particularly high.
supporting documents
- ↑ a b Squatina punctata in the endangered Red List species the IUCN 2010. Posted by: IUCN Shark Specialist Group, 2007. Retrieved on December 28 of 2010.
- ↑ Squatina argentina in the endangered Red List species the IUCN 2010. Posted by: Vooren, CM & Chiaramonte, GE, 2006. Retrieved on December 18 of 2010.
literature
- Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World . Princeton University Press , Princeton and Oxford 2005, pp. 145. ISBN 978-0-691-12072-0 .
Web links
- Spotted angel shark on Fishbase.org (English)