The Panama Long- Mouth Shark [1] ( Rhizoprionodon longurio ) is one of the species of the long- snout sharks ( Rhizoprionodon ), a family of gray sharks ( Carcharhinidae ). These sharks live in the tropical waters of the eastern Pacific. Found at a depth of up to 100 m. The maximum recorded length is 154 cm. Propagated by live birth. They feed on small bony fish, cephalopods and crustaceans . Of little interest to commercial fishing [2] [3] .
| Panama Long-Mouth Shark |
 |
| Scientific classification |
|---|
| No rank : | Bilateral symmetrical |
| View: | Panama Long-Mouth Shark |
|
| International scientific name |
|---|
Rhizoprionodon longurio (DS Jordan & CH Gilbert , 1882) |
| Synonyms |
|---|
Carcharias longurio Jordan and Gilbert, 1882
Scoliodon longurio Jordan and Gilbert, 1882) |
| Area |
|---|
|
| Security status |
|---|
Not enough data IUCN Data Deficient : 161662 |
|
The species was first scientifically described in 1882 [4] . Species epithet comes from the word lat. longus . - "long". The lectotype is a male 79.2 cm long, caught off the coast of Mazatlan , Mexico [5] .
Panamanian long-nosed sharks are common in subtropical waters of the eastern Pacific Ocean between 33 ° C. w. and 16 ° s. w. off the coast of California , Mexico , Guatemala , El Salvador , Honduras , Nicaragua , Costa Rica , Panama , Colombia , Ecuador and Peru . They are kept at a depth of 27 m [6] to 100 m [2] .
The maximum size is 1.1 m (male) and 1.54 m (female). Panamanian long-nosed sharks have a thin body with a long, pointed muzzle. Large, round eyes with a blinking membrane. The distance from the tip of the snout to the nostrils is 4.5-6% of the total length. There are grooves in the corners of the mouth on the upper and lower jaws. The length of the upper labial groove is 2.1-2.6% of the total length. Under the edges of the lower jaw, as a rule, there are 8-15 enlarged pores on each side. The number of dentitions is 26–29 on each jaw. The edges of the teeth are slightly jagged [6] .
Wide, triangular pectoral fins begin under the third or fourth branchial fissure. The base of the first dorsal fin begins above or slightly behind the free ends of the pectoral fins. The second dorsal fin is significantly smaller than the first and is located above the last third of the anal fin. The anterior margin of the pectoral fins is usually equal in length or shorter than the first dorsal fin from the beginning of the base to the free tip. The crest between the dorsal fins is absent. The lower lobe of the caudal fin is well developed; at the tip of the upper lobe there is a ventral notch. Coloring of the dorsal surface of the body of an even gray or gray-brown color, the belly is white. The margins of the pectoral fins are lighter than the main background, the tips of the dorsal fins are dull [6] .
Panamanian long-nosed sharks reach puberty with a length of 58–69 cm [6] . Like other representatives of the family of gray sharks, they breed live births; developing embryos receive nutrition through placental communication with a mother formed by an empty yolk sac [7] . The length of the newborns is 33–34 cm. Pregnancy lasts 10–12 months [8] . Females are likely to breed each year [9] . Males and females are kept apart from each other. The diet consists of bony fish , cephalopods and crustaceans [8] .
This species is an object of artisanal fisheries in coastal waters during the winter and spring months. In summer and autumn, these sharks move to greater depths. They are caught as by- catch using gillnets, longlines, trawls and traps. The meat of Panamanian long-nosed sharks is used for food and for the production of fishmeal . These sharks suffer from overfishing and habitat pollution. They do not pose a danger to humans. Data for assessment by the International Union for Conservation of Nature are not sufficient for the conservation status of the species [3] .
- ↑ Reshetnikov Yu.S. , Kotlyar A.N. , Russ T.S. , Shatunovsky M.I. Fish. Latin, Russian, English, German, French. / edited by Acad. V. E. Sokolova . - M .: Rus. Yaz., 1989 .-- S. 31 .-- 12,500 copies. - ISBN 5-200-00237-0 .
- ↑ 1 2 Panama Long-Mouth Shark in the FishBase database.
- ↑ 1 2 Rhizoprionodon longurio (English) . The IUCN Red List of Threatened Species .
- ↑ Jordan, DS & Gilbert, CH (1882) Description of four new species of sharks, from Mazatlan, Mexico. Proceedings of the United States National Museum, 5: P. 102-110
- ↑ Rhizoprionodon longurio (neopr.) . Shark references.
- ↑ 1 2 3 4 Compagno, Leonard JV Sharks of the World: An Annotated and Illustrated Catalog of Shark Species Known to Date. - Rome: Food and Agricultural Organization, 1984. - S. 528-529. - ISBN 92-5-101384-5 .
- ↑ Dulvy, NK and JD Reynolds. Evolutionary transitions among egg-laying, live-bearing and maternal inputs in sharks and rays // Proc. R. Soc. Lond., Ser. B: Biol. Sci .. - 1997. - Vol. 264. - P. 1309-131.
- ↑ 1 2 Castillo-Géniz, JL 1990. Contribución al conocimiento de la biología y pesquería del cazón bironche, Rhizoprionodon longurio, (Jordan y Gilbert, 1882) (Elasmobranchii, Carcharhinidae), del sur de Sinaloa. B.Sc. Thesis. Universidad nacional Autonoma de México.
- ↑ Pérez-Jiménez, JC, Sosa-Nishizaki, O., Furlong-Estrada, E., Corro-Espinosa, D., Venegas-Herrera, A. and Barragán-Cuencas, OV 2005. Artisanal Shark Fishery at “Tres Marias” Islands and Isabel Island in the Central Mexican Pacific. Journal of Northwest Atlantic Fisheries Science 35 (5): P. 333—343
