Styracura
| Styracura | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Styracura pacifica |
||||||||||||
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name of the subfamily | ||||||||||||
| Styracurinae | ||||||||||||
| Carvalho et al., 2016 | ||||||||||||
| Scientific name of the genus | ||||||||||||
| Styracura | ||||||||||||
| Carvalho , Loboda , Da Silva , 2016 |
Styracura is a genus of rays from the family of freshwater stingrays (Potamotrygonidae). In contrast to all other species of this family, the two species of this genus do not live in South American fresh waters, but near the coast in the sea, Styracura pacifica on the Pacific side of Central America and northern South America from Costa Rica to the Galapagos Islands and Styracura schmardae on the Caribbean side from the southern Gulf of Mexico (Bay of Campeche) over the West Indies to Suriname and the immediately adjacent area of Brazil. Both belonged to the genus Himantura in the family of stingrays (Dasyatidae)until October 2016.
features
The rays are up to 1.5 ( Styracura pacifica ) or 2 meters ( Styracura schmardae ) long. Your body disc is round to slightly rhombic, just as wide as it is long or slightly wider. At the front the edge of the body disc is only slightly sloping, at the back it is broadly rounded. The snout is short and wide and barely protrudes over the body disc, and the pelvic fins barely protrude. The posterior ends of the body disc are slightly removed from the base of the tail. The eyes are small and only a third to half the size of the injection holes . They don't stand out much. The tail is very long and slender, its rear half is whip-like. The tail length is usually twice the distance between the cloaca and the tip of the snout. Low lateral folds of skin extend from the pelvic fins up to half the distance to the tail spine. There is no dorsal ridge on the tail, but short and low ventral folds are present. They reach from the tail sting to just behind it. The tail base is narrower than the eye relief. The tail spine lies directly behind the front third of the tail. It is long, usually twice the distance between the eyes, and well developed. The tail spine is narrow and only as wide as the tail at the level of the spine. The placoid scales are star-shaped, relatively large and blunt. Each individually has patterns of radially arranged ridges. They stand close together, partially overlap, and are evenly distributed on the top of the body disc and on the top of the tail. Smaller scales with a single point and a star-shaped base plate are found on the edges of the body disc and in the rear tail area. In the shoulder region there are two large placoid scales that are also star-shaped but have well-developed longitudinal ridges. The pelvic fins and the ventral side are scaly. However, there are small sharp scales on the underside of the tail behind the tail sting. The rays of the genus Styracura are monochrome gray, gray-brown or olive-brown to purple-brown in color. The pelvic fins and tail are darker.
species
- Styracura pacifica (Beebe & Tee-Van, 1941)
- Styracura schmardae (Werner, 1904)
literature
- Carvalho, MRd, Loboda, TS & Silva, JPCBd (2016): A new subfamily, Styracurinae, and new genus, Styracura , for Himantura schmardae (Werner, 1904) and Himantura pacifica (Beebe & Tee-Van, 1941) (Chondrichthyes: Myliobatiformes). Zootaxa , 4075 (3): 201-221. doi: 10.11646 / zootaxa.4175.3.1