Fluvitrygon signifer

Fluvitrygon signifer
	Fluvitrygon signifer
Systematics
Subclass :	Plate gill (Elasmobranchii)
without rank:	Stingray (batoidea)
Order :	Myliobatiformes
Family :	Stingrays (Dasyatidae)
Genre :	Fluvitrygon
Type :	Fluvitrygon signifer
Scientific name
	Fluvitrygon signifer
	( Compagno & Roberts , 1982)

Fluvitrygon signifer is a very rare stingray species found in the freshwater and estuary areas of rivers in Thailand , Sumatra and Borneo . It has been proven in the Kapuas in western Borneo, in the Indragiri in Sumatra, in the Perak in the west of the Malay Peninsula and in the lower Chao Phraya in Thailand.

features

The body disc of Fluvitrygon signifer is oval-rhombic and slightly longer than it is wide (the maximum measured length is around 60 cm). The whip-like tail is very long, so that the total length of the animals can be over 2 meters. The fish are brownish on top, the underside and the tail behind the two spines are whitish. A white band along the edge of the body disc is characteristic of the species. The muzzle protrudes and forms a triangular tip. The eyes are small, the injection holes are significantly larger than the eyes. The mouth is arched. In the upper jaw the animals have a total of 38 to 45 rows of teeth, in the lower jaw there are 37 to 46 rows of teeth. The teeth are arranged like a quincunx in both jaws . The teeth are blunt-conical with transverse cutting edges. The cutting edges are higher and serrated in the males, lower and blunt in the females.

Way of life

Little is known about the way of life of Fluvitrygon signifer . The species appears to be found above sandy soils and feeds on benthic invertebrates such as mussels and crustaceans. In specimens from the Kapuas, worms from the order of the little bristle (Oligochaeta) and insects were also found in the stomach . It also reproduces in fresh water and is ovoviviparous , the fry first feed on the yolk in the uterus, then on a protein-rich secretion that is released from special glands in the uterus. Stings from the stingray species can cause severe injuries and are extremely painful.

Systematics

The ray species was scientifically described for the first time in 1982 by the US marine biologists Leonard Compagno and Tyson R. Roberts under the name Himantura signifer . In 2016, the genus Fluvitrygon was introduced for three Southeast Asian freshwater ray species .

supporting documents

↑ Fluvitrygon signifer in the endangered Red List species the IUCN 2016 Posted by: Compagno, Hunting Association, 2005. Retrieved on November 11 of 2019.
↑ ^a ^b ^c ^d Compagno, LJV & TR Roberts (1982). Freshwater stingrays (Dasyatidae) of Southeast Asia and New Guinea, with description of a new species of Himantura and reports of unidentified species. Environmental Biology of Fishes. 7 (4): 321-339. doi: 10.1007 / BF00005567
↑ ^a ^b Fluvitrygon signifer on Fishbase.org (English)
↑ Last, PR, Naylor, GJP & Manjaji-Matsumoto, BM (2016): A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights. Zootaxa , 4139 (3): 345-368. doi: 10.11646 / zootaxa.4139.3.2 , page 360.

[IUCN-1] Fluvitrygon signifer in the endangered Red List species the IUCN 2016 Posted by: Compagno, Hunting Association, 2005. Retrieved on November 11 of 2019.

[Compagno-2] Compagno, LJV & TR Roberts (1982). Freshwater stingrays (Dasyatidae) of Southeast Asia and New Guinea, with description of a new species of Himantura and reports of unidentified species. Environmental Biology of Fishes. 7 (4): 321-339. doi: 10.1007 / BF00005567

[fishbase-3] Fluvitrygon signifer on Fishbase.org (English)

[Last-4] Last, PR, Naylor, GJP & Manjaji-Matsumoto, BM (2016): A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights. Zootaxa , 4139 (3): 345-368. doi: 10.11646 / zootaxa.4139.3.2 , page 360.