| Family: |
Dasyatidae (Stingrays), subfamily: Urogymninae |
| Max. size: |
40 cm WD (male/unsexed) |
| Environment: |
demersal; freshwater |
| Distribution: |
Africa: Benue River in Cameroon and Nigeria, and Niger River downstream from its confluence with the Benue River (Ref. 3497, 81259). Also reported from Lagos Lagoon, Cross River and Sanaga River (Ref. 81259, 81625). |
| Diagnosis: |
Vertebrae: 120-131. Diagnosis: A moderately large and thin-bodied freshwater dasyatid; disc flatter than in any other West African dasyatid, its depth only 8.7-11.0% of disc width vs. 11.0% or more in other species; denticles on dorsal surface of disc highly variable, sometimes absent, always restricted to central portion; pearl spine absent or represented by 2-3 low denticles (Ref. 26277). It is most similar to the small marine species Dasyatis margaritella and the larger marine species Dasyatis margarita, both of which have well-developed pearl spines and shorter snouts (Ref. 26277).
Description: Disc oval, strongly flattened and broadly rounded at corners; tip of snout projecting as a small triangular process beyond anterior disc margin (Ref. 31256, 81259, 81625). Mouth slightly arched; upper jaw with 5-7 and lower jaw with 7-9 functional tooth series; a total of 32-40/37-45 rows of jaw teeth; teeth in males with a central cusp, blunt in females; a transverse row of five elongated fleshy mouth papillae (Ref. 26277, 81259, 81625). Nasal curtain posteriorly fringed, eyes and spiracles adjacent (Ref. 81625). Pelvic fins mostly concealed by disc in dorsal view (Ref. 81625). Tail long and thin, whip-like, with a denticulate sting at base, a short dorsal ridge behind the sting, and a ventral fold; tail base oval in cross-section with greatest width at base not as great as interorbital distance; caudal sting markedly lender (Ref. 81259, 81625). Skin armour variable: disc smooth in juveniles, the dermal denticles appearing with growth; the granulation remains restricted to the central disc area, sometimes including a nacreous tubercle, and usually a longitudinal row of 2-4 rounded or heart-shaped tubercles (Ref. 81259).
Colouration: Back of disc and pelvic fins uniformly brownish- to greyish-beige or gray-brown above, without spots or prominent markings, although some specimens have diffuse dark marblings; white below and without dark margins; tail brownish, darker or blackish behind the sting, lighter below (Ref. 26277, 81259, 81625). |
| Biology: |
Dasyatis garouaensis is restricted to fresh waters (Ref. 81625). Its conservation status is uncertain, given its restricted distribution in a region with known habitat degradation; this species has apparently become less common after the construction of a dam on the Benue River (Ref. 81625). Ovoviviparous (Ref. 50449). |
| IUCN Red List Status: |
Critically Endangered (CR); Date assessed: 04 August 2020 (A2cd) Ref. (130435)
|
| Threat to humans: |
harmless |
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