Elasmobranchii (sharks and rays) > Myliobatiformes
(Stingrays) > Dasyatidae
Etymology: Dasyatis: Greek, dasys = rough, dense (Ref. 45335); garouaensis: Named for its geographical localization (Ref. 39828).
Environment / Climate / Range
Freshwater; demersal. Tropical, preferred ?
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).
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 40.0 cm WD male/unsexed; (Ref. 3497)
Morphology | Morphometrics
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).
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).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Exhibit ovoviparity (aplacental viviparity), with embryos feeding initially on yolk, then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus, fat or protein through specialised structures (Ref. 50449). Distinct pairing with embrace (Ref. 205).
Compagno, L.J.V. and T.R. Roberts, 1984. Dasyatidae. p. 4-5. In J. Daget, J.P. Gosse and D.F.E. Thys van den Audenaerde (eds.) Check-list of the freshwater fishes of Africa (CLOFFA). ORSTOM, Paris and MRAC, Tervuren. Vol. 1. (Ref. 3497)
IUCN Red List Status (Ref. 109396)
CITES (Ref. 94142)
Threat to humans
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01202 (0.00490 - 0.02951), b=3.03 (2.81 - 3.25), based on LWR estimates for this (Sub)family-body shape (Ref. 93245
Trophic Level (Ref. 69278
): 3.7 ±0.2 se; Based on size and trophs of closest relatives
Resilience (Ref. 69278
): Very Low, minimum population doubling time more than 14 years (Assuming Fec<10).
Vulnerability (Ref. 59153
): Very high vulnerability (90 of 100) .