Dipturus acrobelus (lat.) Is a species of cartilaginous fish of the rhombus family of rays of the order of stingrays. They live in the eastern Indian and southwestern Pacific . They are found at a depth of 1328 m. Their large, flattened pectoral fins form a rhombic disk with an elongated and pointed snout. The maximum recorded length is 137.1 cm. Eggs are laid. They are not the target fishing target [1] [2] [3] .
| Dipturus acrobelus |
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| No rank : | Bilateral symmetrical |
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Dipturus acrobelus Last , WT White & Pogonoski , 2008 |
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Least ConcernedIUCN 3.1 Least Concern : 195444 |
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The species was first scientifically described in 2008 [4] . The holotype is an 84 cm long immature male, caught off the coast of Tasmania ( ) at a depth of 905–990 m. Paratypes: females 21.4 long —135 cm, an adult male more than 89 cm long and immature males 24.2–41.3 cm long, caught there at a depth of 770–1328 m; 46.4 cm immature male caught in the Gulf of Australia at a depth of 876–923 m; females with a length of 50.6-105.5 cm and an immature male 21.3 cm long, caught in the waters of New South Wales at a depth of 485-925 m; females 20.2-57.4 cm long, caught off the coast of Victoria at a depth of 502-1060 m and a male and female 21.9 cm and 21.4 cm long, caught off the coast of South Australia at a depth of 800-820 m [5] .
These bathydemersal rays are endemic to the waters of Australia (Victoria, South Australia, Tasmania, New South Wales, Western Australia ). They are found at a depth of 446 to 1328 m. Mostly between 800 and 1000 m [2] .
The wide and flat pectoral fins of these rays form a rhombic disk with a rounded snout and rounded edges. On the ventral side of the disc are 5 gill slits, nostrils and mouth. On the long tail there are lateral folds. These skates have 2 reduced dorsal fins and a reduced caudal fin [1] .
The width of the disk is 1.1-1.2 times the length and equal to 66-71% of the length of the body. The knotted and pointed snout forms an angle of 60–74 °. The length of the tail is 0.7-1 distance from the tip of the snout to the cloaca. The tail is thin, has a rounded cross section, in the middle part it expands slightly. The width of the tail in the middle part is 1.6–1.8 of its height and 1.4–1.8 at the base of the first dorsal fin. The distance from the tip of the snout to the upper jaw is 24–27% of the body length and is 3–3.4 times greater than the distance between the nostrils. The length of the head along the ventral side is 35–38% of the body length. The length of the snout is 5.4–7 times greater, and the diameter of the eye is 55–92% of the interorbital space. The height of the first dorsal fin is 1.2–2.1 times the length of its base. The distance between the beginning of the base of the first dorsal fin and the tip of the tail exceeds 3-4 times the length of its base and 2.6-3.5 times the length of the caudal fin. The ventral fins are medium sized. The front edge of large individuals (> 135 cm), regardless of gender, is covered with a barbed strip. There are 1-3 spines in the occipital region, malar spines are well developed, in males the tail is covered with 1-3 rows of spines (lateral rows developed worse than the central one). Females have additional dorsolateral and sometimes ventrolate rows of spines (for a total of up to 7 rows). The pectoral fins are formed by 83–88 rays. The number of vertebrae is 130-141. On the upper jaw there are 35–41 dentitions. The dorsal surface of the disc is brown or gray. The ventral surface is dark brown or blackish, sometimes speckled. The snout tip is darker than the main background. The upper lip usually has a black border. The sensitive pores located on the ventral side of the disc are very small, with slightly dark edges. In small individuals (<57 cm), the dorsal and caudal fins, the tip of the tail, the edges of the ventral fins and the posterior edge of the pectoral fins are black [4] . The maximum recorded length is 137.1 cm [4] .
Like other rhombic, these stingrays lay eggs enclosed in a rigid horn capsule with protrusions at the ends. Embryos feed exclusively on yolk [3] . Males reach puberty with a length of 89–95 cm. The smallest free-swimming individual was 20.2 cm long [2] .
These skates are not subject to targeted fishing. Potentially by- catch . Previously caught skates were thrown overboard, but due to increased demand, large individuals are kept for sale in local markets. The International Union for Conservation of Nature has assigned the conservation status of “Least Concerns” [2] .
- ↑ 1 2 Froese, Rainer, and Daniel Pauly, eds. Family Rajidae - Skates (Neopr.) . FishBase
- ↑ 1 2 3 4 Dipturus acrobelus (English) . The IUCN Red List of Threatened Species .
- ↑ 1 2 Dipturus acrobelus (English) in the FishBase database.
- ↑ 1 2 3 Last P., White WT & Pogonoski JJ New skates of the genus Dipturus (Rajoidei: Rajidae) from Australian Seas // CSIRO Marine and Atmospheric Research Paper. - 2008 .-- Vol. 21. - P. 9-52.
- ↑ Dipturus acrobelus (neopr.) . Shark-References. Date of treatment May 26, 2016.
