Stingrays

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Stingrays
Blue-spotted ray (Taeniura lymma)

Blaupunktrochen ( Taeniura lymma )

Systematics
Class : Cartilaginous fish (Chondrichthyes)
Subclass : Euselachii
Subclass : Plate gill (Elasmobranchii)
without rank: Stingray (batoidea)
Order : Myliobatiformes
Family : Stingrays
Scientific name
Dasyatidae
Jordan , 1888

The piercing - sting - or Whiptail rays (Dasyatidae) are a family of rays . The family includes almost 20 genera with over 100 species .

features

Depending on the species, stingrays are small to very large (22 to 260 cm wide). The back side is monochrome or patterned to a greater or lesser extent and is usually darker than the belly side. The body is flattened to varying degrees and, together with the pectoral fins, oval, approximately round or rhombic. The head is fully integrated into the body disc. The snout is angular or blunt, sometimes very elongated. The skirt-like nasal membranes around the nostrils are well developed. Stingrays have five gill slits. The tail can be short and strong but also more or less long with a slim base, sometimes very long and whip-like. The back of the fish is smooth or very prickly and has thorny placoid scales or tubercles. Often there is a central band of thorns. The dorsal and caudal fins are absent. The tail has one to four spines and in the middle on the underside, sometimes also on the top, a skin fold of varying degrees of development.

The tail spines are partially barbed and covered by glandular tissue that contains poison. Like the teeth of rays, these stings are regularly replaced every one to two years. The spiked tail is mainly used for defense and is thrown forward over the body in case of danger.

distribution

The distribution area of ​​the stingrays mainly includes the Indo-Pacific area between the Red Sea and East Africa to the reefs off the Australian coast, but there are also occurrences in the Atlantic, such as the American stingray ( Dasyatis americana ) from the Canaries to the American coasts between New Jersey and Brazil or the common stingray ( Dasyatis pastinaca ) from the North Sea to the Canary Islands . Most species live exclusively in the sea.

In contrast to the representatives of the freshwater stingray family , which occur exclusively in the river systems of South America, there are also species of stingrays that migrate from the sea up the rivers, such as the feather-tailed stingray ( Pastinachus sephen ). Only a few species, such as the Laos stingray ( Hemitrygon laosensis ), live exclusively in rivers.

Sting of a stingray

Systematics

About 90 species are counted among the stingrays, which are grouped into 19 genera and four subfamilies. In addition, there are some known but previously undescribed species.

Remarks

  1. ↑ Sister species of a clade from the freshwater stingray (Potamotrygonidae) and the American round stingray (Urotrygonidae). Is only provisionally assigned to the Dasyatidae.

literature

Individual evidence

  1. ↑ a b 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
  2. ↑ Petean, FF, Naylor, GJP & Lima, SMQ: Integrative taxonomy identifies a new stingray species of the genus Hypanus Rafinesque, 1818 (Dasyatidae, Myliobatiformes) from the Tropical Southwestern Atlantic. Journal of Fish Biology, August 2020, doi: 10.1111 / jfb.14483

Web links

Commons : Stingrays  - Collection of images, videos and audio files