Wide Urolof [1] ( lat. Urolophus expansus ) is a species of the genus Urolophus of the family of short-tailed stingrays of the order of the caudate . It is endemic to the southwest coast of Australia . It occurs at a depth of up to 420 m. The pectoral fins of these slopes form a diamond-shaped disk, the width of which exceeds the length. The dorsal surface of the disc is painted gray-green, with dull lines behind the eyes. Between the nostrils is a rectangular fold of skin. The short tail ends with a leaf-like caudal fin. A jagged spike is located in the middle of the caudal peduncle. Dorsal fins absent. Maximum recorded length 52 cm.
| Wide urolof |
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| Scientific classification |
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| No rank : | Bilateral symmetrical |
| Family: | Short-tailed Stingers |
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| International scientific name |
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Urolophus expansus McCulloch , 1916 |
| Security status |
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Least ConcernedIUCN 3.1 Least Concern : 60092 |
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Propagated by egg production . The diet consists mainly of isopods and polychaetes . Not an object of target fishing. By- catch is regularly caught in commercial fisheries [2] [3] .
Content
The species was first scientifically described by the Australian ichthyologist Alan Riverstone McCallock in 1916 on the basis of an individual caught by the Endivore research vessel in the Great Australian Gulf [4] . Species epithet comes from the word lat. expansus is “expanded” [5] and is associated with the disk width of these slopes.
Broad urolofs inhabit the southwestern coast of Australia from Perth , Western Australia to Port Lincoln , South Australia [6] . These fish are found on the outer edge of the continental shelf and in the upper part of the continental slope at a depth of 130 to 420 m. Most often they can be found between 200 and 300 m on the sandy bottom. Probably, there is some segregation by sex and age [2] [6] .
The wide pectoral fins of these slopes merge with the head and form a diamond-shaped disk, the width of which is much greater than the length. The “wings” are rounded, the front edge of the disk is slightly curved, the pointed fleshy snout forms an obtuse angle and protrudes beyond the edges of the disk. Behind large eyes are comma- shaped sprays . There is sometimes a protrusion on the posterior edge of the nostrils, and between the nostrils lies a leather flap with a shallow-edged posterior edge. The medium-sized mouth contains small teeth with oval bases. At the bottom of the oral cavity there are 6-9 finger-shaped processes, the same processes cover the lower jaw. On the ventral side of the disk there are 5 pairs of short gill slits . Small ventral fins rounded [6] [7] .
The length of the short tail is 71–93% of the total length. It is flattened, folds of skin lie on both sides of the caudal stem. The tail narrows and turns into a long and low lanceolate caudal fin. A notched spike is located on the dorsal surface of the tail in the central part. Dorsal fins absent. The skin is devoid of scales . The maximum recorded length is 52 cm. The color is dull green, two bluish transverse stripes are located behind the eyes, similar inclined lines are in front of the eyes. The ventral surface is white or beige with dark spots at the tail. In young individuals, the tail is dark [6] .
Broad urolofs prey mainly on isopods and polychaetes. Like other caudate-like, these rays are reproduced by ovipositor production. Litter is probably small. Males reach puberty with a length of 30-36 cm at the age of 7 years, their maximum recorded life expectancy is 11 years. Females mature at a length of 40 cm [2] [6] . Acanthobothrium tapeworms parasitize Urolophus bucculentus [8] .
These stingrays are not targeted, although their meat is edible. By- catch are regularly found in commercial fisheries. Caught fish are thrown overboard, the survival rate among them is probably low, since they are raised from great depths. The International Union for Conservation of Nature has assigned this species a conservation status of “Least Concerns” [2] .
- ↑ Reshetnikov Yu.S. , Kotlyar A.N. , Russ T.S. , Shatunovsky M.I. The Bilingual Dictionary of Animal Names. Fish. Latin, Russian, English, German, French. / edited by Acad. V. E. Sokolova . - M .: Rus. Yaz., 1989 .-- P. 44 .-- 12,500 copies. - ISBN 5-200-00237-0 .
- ↑ 1 2 3 4 Urolophus expansus (English) . The IUCN Red List of Threatened Species .
- ↑ Wide urolof in the FishBase database.
- ↑ McCulloch, AR (October 31, 1916). "Report on some fishes obtained by the FIS" Endeavor "on the coasts of Queensland, New South Wales, Victoria, Tasmania, South and South-Western Australia." Biological Results Endeavor. Part IV 4 (4): 169-199.
- ↑ Large Latin-Russian Dictionary. (unspecified) . Date of treatment April 9, 2014.
- ↑ 1 2 3 4 5 Last, PR; Stevens, JD Sharks and Rays of Australia. - (second ed.). - Harvard University Press, 2009. - P. 414-415. - ISBN 0—674-03411—2.
- ↑ Last, PR and LJV Compagno. Myliobatiformes: Urolophidae ". In Carpenter, KE and VH Niem. FAO identification guide for fishery purposes: The living marine resources of the Western Central Pacific. - Food and Agricultural Organization of the United Nations, 1999. - P. 1469-1476. - ISBN 92-5-104302-7.
- ↑ Campbell, RR and I. Beveridge (2002). "The genus Acanthobothrium (Cestoda: Tetraphyllidea: Onchobothriidae) parasitic in Australian elasmobranch fishes." Invertebrate Systematics 16 (2): 237–344.
- Species Wide urolof (English) in the World Register of Marine Species .
