The pointed tail [1] ( Dasyatis zugei (Latin) ) is a species of the tails from the family of the caudal tail detachment of the tails of the colostrals above the detachment of skates . They inhabit the tropical waters of the eastern Indian Ocean and in the northwestern and western parts of the Pacific Ocean . They are found at a depth of up to 100 m. The maximum recorded width of the disk is 29 cm. The pectoral fins of these rays grow together with the head, forming a diamond-shaped disk. Snout elongated and pointed. The tail is longer than the disc. Behind the spike on the caudal stem are the lower and upper skin keels. Coloring of a dorsal surface of a disk of dark chocolate color. Like other caudal-like, sharp-tailed caudal duplicates reproduce by egg production . Embryos develop in the womb, feeding on the yolk and histotrophs . In litter 1-3 newborns. The diet consists of small crustaceans and fish. Not targeted, but caught by- catch . Meat is used in food [2] [3] .
Pointed tails |
|
Scientific classification |
---|
No rank : | Bilateral symmetric |
|
International Scientific Name |
---|
Dasyatis zugei JP MΓΌller and Henle |
Synonyms |
---|
- Trygon crozieri Blyth, 1860
- Trygon zugei MΓΌller & Henle, 1841
- Dasyatis cheni Teng, 1962
- Amphotistius zugei (MΓΌller & Henle, 1841)
|
Security status |
---|
Close to VulnerabilityIUCN 3.1 Near Threatened : 60160 |
|
Content
Taxonomy and phylogenesisFor the first time a new species was scientifically described in 1841 by German biologists Johann Muller and Friedrich Henle as Trygon zugei [4] . Subsequent authors have recognized the genus Trygon as synonymous with the genus Dasyatis [5] . The specific epithet is derived from the Japanese name for this tail bone Jap. γ° γ¨ γ€ . Earlier spiny tails were confused with Dasyatis acutirostra , however, these species differ ( Dasyatis acutirostra has large eyes, dorsal fold on the tail is almost invisible, larger radial rays of the pectoral and pelvic fins and a greater number of turns of the spiral valve ). In 1988, a study was published, [3] . confirming these differences, and a new lectotype of the species of acute tails was appointed [6] .
In 2001, a phylogenetic analysis of 14 species of tailings, based on morphology , was published. In it, the pointed tails, Dasyatis margaritella and Himantura gerrardi were recognized as closely related species, forming a clapboard with a smooth butterfly slope , as root species . These data reinforce the view that neither the tailing species nor the tailings-himanture genus is monophyletic [7] .
Habitat and habitatSharp tails are widespread throughout the Indian Ocean right up to the western Pacific Ocean. They live off the coast of Bangladesh , Cambodia , China , India , Indonesia , Malaysia , Myanmar , the Philippines , Sri Lanka , Taiwan , Thailand and Vietnam . These slopes are found on the continental shelf at a depth of up to 100 m. Often they swim in the estuaries of rivers. Prefer sandy bottom [3] [2] .
DescriptionThe pectoral fins of these rays grow together with the head, forming a rhomboid flat disk, whose width exceeds the length, with rounded fins (βwingsβ). The front edge is strongly extended and forms a triangular pointed snout. Behind the small eyes are sprinklers that exceed their size. On the ventral surface of the disk are 5 gill slits, mouth and nostrils. Between the nostrils runs a skin flap with a fringed lower edge. The mouth is curved in the form of an arc; there are no processes at the bottom of the mouth. The teeth are staggered and form a flat surface. Unlike females and immature individuals, the teeth of males are pointed. In the mouth of 40-55 dentitions in the upper and lower jaws [6] [8] . Pelvic fins have a triangular shape. The whipped tail is much longer than the disc. Like other caudal tails on the dorsal surface in the central part of the caudal stem is a serrated spike, connected by ducts with a poisonous gland. Sometimes skates have 2 spikes. Periodically, the spike breaks off and a new one grows in their place. Behind the spike on the caudal stem are ventral and dorsal skin folds. The skin of young stingrays is devoid of scales. In adults, there are 5-6 plaques in front of the thorn. Coloring of the dorsal surface of the disc smooth chocolate brown. The ventral surface of the disc is white with a dark border around the edge [6] . The maximum recorded length is 75 cm, and the width of the disk is 29 cm, while on average the disk is no wider than 18β24 cm [6] .
BiologyLike the other caudate-like, sharp-tailed caudal tails, they belong to the egg- breeding fish. Embryos develop in the womb, feeding on the yolk and histotrophs. In the litter 1-3 newborns 8-10 cm wide across the disk. Males and females reach sexual maturity with a disc width of 18 and 19 cm, respectively [3] . The diet of these skates consists mainly of benthic crustaceans, as well as small fish [2] [3] . Acute worms are parasitized by tapeworms Acanthobothrium zugeinensis [9] , ochthaus ohl ohns ohm ohm oh oh ohm oh oh oh hryvΓ‘v Δ±n Δ± h Δ± h Δ± h Δ± th p th o f o h Δ± th Δ± th o f th y th o th y o p th o p ho p p th o p p p us th o p ho p th o p p p us p us p th ΠΈ ΠΈ P. P. P. P. P. P. P. P. P. P. P. P. P. Poly Poly Poly Poly Poly Poly raoi [16] , Tylocephalum singhii [17] and Uncibilocularis indiana and U. veravalensis [18] [19] and monogenes Trimusculotrema schwartzi [20] .
Human interactionBecause of their small size, pointed tailings are not the object of target fishing, however, they are caught in large numbers as by-catch in commercial fishing in the Gulf of Siam , the Java Sea and off the coast of India . Meat is eaten. The International Union for Conservation of Nature has assigned the status of βClose to a vulnerable positionβ to this species, although it is approaching the status βVulnerableβ [3] .
Notes- β Reshetnikov Yu. S. , Kotlyar A. N. , Russ T. S. , Shatunovsky M. I. Pyatiazychny dictionary of animal names. Fish. Latin, Russian, English, German, French. / edited by Acad. V.E. Sokolova . - M .: Rus. lang., 1989. - 733 p. - 12 500 copies - ISBN 5-200-00237-0 .
- β 1 2 3 pointed tails (English) in FishBase database.
- β 1 2 3 4 5 6 Dasyatis zugei (English) . The IUCN Red List of Threatened Species .
- β MΓΌller, J. & Henle, FGJ (1841) Systematische Beschreibung der Plagiostomen. Berlin, Veit, pp. 1β200
- β Jordan, DS and HW Fowler. A review of the elasmobranchiate fishes of Japan // Proceedings of the United States National Museum. - 1903. - Vol. 26, No. 1324 . - P. 593-674. - DOI : 10.5479 / si.00963801.26-1324.593 .
- β 1 2 3 4 Nishida, K. and K. Nakaya. A new species of the genus Dasyatis (Elasmobranchii: Dasyatididae) from Southern Japan and lectotype designation of D. zugei // Japanese Journal of Ichthyology. - 1988. - Vol. 35, No. (2) . - P. 115-123.
- β Rosenberger, LJ; Schaefer, SA Phylogenetic Relationships within the Stingray Genus Dasyatis (Chondrichthyes: Dasyatidae) // Copeia. - American Society of Ichthyologists and Herpetologists, 2001. - No. 3 . - P. 615-627. - DOI : 10.1643 / 0045-8511 (2001) 001 [0615: PRWTSG] 2.0.CO; 2 .
- β Nishida, K. and K. Nakaya. Taxonomy of the genus Dasyatis (Elasmobranchii, Dasyatididae) from the North Pacific. = in Pratt, HL, SH Gruber and T. Taniuchi. Elasmobranchs as living resources: advances in biology, ecology, systematics, and behavior, NOAA Technical Report // NMFS. - 1990. - Vol. 90. - P. 327-326.
- β Yang, WC and YG Lin. Two new species of Acanthobothrium cestodes (Tetraphyllidea: Onchobothriidae) from saltwater fishes in Xiamen, South Fujian, China // Journal of Xiamen University Natural Science. - 1994. - Vol. 33, No. 33 (4 Supplement 121) . - P. 532-536.
- β Jadhav, BV and GB Shinde. A review of the genus Balanobothrium Hornell, 1912 with four new species // Helminthologia. - 1982. - Vol. 19, no. (3) . - P. 185-194.
- β Muralidhar, A., GB Shinde and BV Jadhav (1987). Pithophorus zugeii sp. nov. (Cestoda: Phyllobothridae) from a marine fish at Madras, India. Indian Journal of Helminthology 39 (1): 47β50. Jump up Jadhav, BV, GB Shinde and DV Sarwad
- β Jadhav, BV, GB Shinde and DV Sarwade (1986). Polypocephalus ratnagiriensis sp. nov. (Cestoda: Lecanicephalidae) from Trygon zugei, India. Indian Journal of Helminthology 38 (2): 88β92.
- β Vankara, AP, C. Vijayalakshmi and J. Vijayalakshmi (December 2007). Polypocephalus visakhapatnamensis sp. nov. (Lecanicephalidea: Polypocephalidae) from Himantura uarnak (Forsskal) and Dasyatis (Amphotistius) zugei (Mueller & Henle) from Visakhapatnam coast. Journal of Parasitic Diseases 31 (2): 152-154.
- β Wang, YH and WC Yang. Rhinebothrium xiamenensis n. sp. (Eucestoda: Tetraphyllidea) in Dasyatis zugei from the coast of Xiamen, China // Journal of Parasitology. - 2001. - Vol. 87, No. (1) . - P. 185-187. - DOI : 10.1645 / 0022-3395 (2001) 087 [0185: RXNSET] 2.0.CO; 2 .
- β Jadhav, BV, GB Shinde and RA Deshmukh (1981). On a new cestode Shindeiobothrium karbharae gen. n. sp. n. from a marine fish. Rivista di Parassitologia 42 (1): 31-34.
- β Deshmukh, RA and GB Shinde (1979). Three new species of Tetragonocephalum Shipley and Hornell, 1905 (Cestoda: Tetragonocephalidae) from the marine fishes of the west coast of India. Bioresearch (Ujjain) 3 (1): 19-23.
- β Jadhav, BV and GB Shinde (1981). A new species of the genus Tylocephalum Linton, 1890 (Cestoda: Lecanicephlidea) from an Indian marine fish. Indian Journal of Parasitology 5 (1): 109-111.
- β Jadhav, BV, GB Shinde, A. Muralidhar and AD Mohekar (1989). Two new species of the genus Uncibilocularis Southwell, 1925 from (Cestoda: Onchobothriidae) India. Indian Journal of Helminthology 41 (1): 14β20.
- β Jadhav, BV and GB Shinde (1981). Uncibilocularis veravalensis n. sp. (Cestoda: Onchobothriidae) from an Indian marine fish ". Indian Journal of Parasitology 5 (1): 113-115.
- β Dyer, WG and WJ Poly. Trimusculotrema schwartzi n. sp. (Monogenea: Capsalidae) Dasyatis zugei (Elasmobranchii: Dasyatidae) off Hong Kong, China // Systematic Parasitology. - 2002. - Vol. 51, No. (3) . - P. 217-225. - DOI : 10.1023 / A: 1014538529942 . - PMID Dyer, WG and WJ Poly (March 2002). "Trimusculotrema schwartzi n. Sp. (Monogenea: Capsalidae) Dasyatis zugei (Elasmobranchii: Dasyatidae) off Hong Kong, China." Systematic Parasitology 51 (3): 217β225. doi: 10.1023 / A: 1014538529942. PMID 11912347 .
Links- Species The pointed tails (Eng.) In the World Register of Marine Species .