Brazilian Sharpnose Shark
| Brazilian Sharpnose Shark | ||||||||||||
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Brazilian Sharpnose Shark ( Rhizoprionodon lalandii ) |
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| Rhizoprionodon lalandii | ||||||||||||
| ( Müller & Henle , 1839) |
The Brazilian sharp-nosed shark ( Rhizoprionodon lalandii ) is a species of the sharp-nosed sharks ( Rhizoprionodon ) within the Requiem sharks (Carcharhinidae). The species is found in the tropical waters of the South American coast from Panama to Brazil.
Appearance and characteristics
The Brazilian sharp-nosed shark is a medium-sized shark with an average body length of around 50 to 70 cm and a maximum length of around 77 centimeters. He has a dark gray to gray-brown body color and a lighter belly region without pattern. The underside of the pectoral fins is also light, the dorsal fins gray. The muzzle is long and the mouth is broadly parabolic when viewed from below, the eyes are large and are located relatively high up on the head. The nostrils are narrow and elongated, compared to other species in the same range as the Caribbean Sharpnose Shark ( R. porosus ) and the Atlantic Sharpnose Shark ( R. terranovae ) with long labial folds.
It has an anal fin and two dorsal fins . The first dorsal fin is significantly larger than the second and lies slightly in front of or over the free ends of the pectoral fins, while the second only arises behind the anal fin. The anal fin is slightly larger than the very small second dorsal fin. The caudal fin has a relatively short lower and long upper lobe with a distinct end lobe. Like all species of the genus, the animals have five gill slits and no injection hole , the 4th and 5th gill slits are above the pectoral fin attachment.
Way of life
The Brazilian sharp-nosed shark is a shallow-water species and predatory feeds mainly on various fish from the shore zones, and it also hunts crustaceans , snails and cuttlefish . The sharks are viviparous and form a yolk sac placenta ( placental viviparous ). The females get between one and four young animals with a length of about 33 cm in one litter. With a body length of about 45 to 50 cm, the males, from about 54 cm, the females are sexually mature.
distribution
The Brazilian sharp-nosed shark is found in the western Atlantic in the tropical waters of the South American coast from Panama to Brazil. Its habitat is in the area of the continental shelf in water depths down to the bottom at a depth of 0 to 70 meters. It prefers sandy to muddy subsoil, and is rarely found in lagoons and estuaries .
literature
- Leonard Compagno , Marc Dando, Sarah Fowler: Sharks of the World. Princeton Field Guides, Princeton University Press , Princeton and Oxford 2005; P. 318, ISBN 978-0-691-12072-0 .
Web links
- Brazilian Sharpnose Shark on Fishbase.org (English)
- Rhizoprionodon lalandii inthe IUCN 2013 Red List of Threatened Species . Posted by: Rosa, RS, Gadig, OBF, Santos Motta, F. & Namora, RC, 2004. Retrieved December 4, 2013.