Paratrygon parvaspina Loboda, Lasso, Rosa & Carvalho, 2021

Family:  Potamotrygonidae (River stingrays), subfamily: Potamotrygoninae
Max. size:  54.3 cm WD (male/unsexed)
Environment:  demersal; freshwater
Distribution:  South America: endemic to the Orinoco basin (n middle portion of the Orinoco River and its main affluents, the Bita and Tomo rivers).
Diagnosis:  This species is distinguished by the following set of characters: spiracular process extremely short and reduced, slightly more developed in adults, and with few dermal denticles (vs. with large and knob shaped spiracular processes that almost cover the spiracle aperture in aiereba, and with short and straight spiracular process with developed dermal denticles in orinocensis); caudal sting very reduced, with mean of its length 6.2% DW [5.6-7.1% DW] (vs. longer caudal stings in aiereba and orinocensis with means and ranges, respectively, 11.3% DW [3-17.9% DW], and 11.9% DW [6.7-15.3% DW]); tail short, with means of the pre-caudal sting region and the distance between cloaca and tail tip, respectively, 21.1% and 50.4% DW (vs. longer tails in aiereba and orinocensis, with means of the pre-caudal sting region and the distance between cloaca and tail tip, respectively, 23.5% and 87.8% DW in aiereba, and 25.2% and 115.4% DW in orinocensis); anterior disc margin broadly rounded (vs. with well developed and visible concave anterior disc margins, especially the latter in aiereba and orinocensis; spiracles small and quadrangular, with mean length 5.2% DW [4.9-5.8% DW] (vs. larger spiracles with mean length 6% DW [4.4-11.6% DW] in aiereba, and with triangular and slightly smaller spiracles, with mean spiracle length 5.6% DW [4.5-7.9% DW] in orinocensis); rostral projection relatively large (vs. small or minute in aiereba and orinocensis, respectively); preorbital processes more laterally projected, externally exceeding level of nasal capsules (vs. preorbital processes less laterally projected, not exceeding level of nasal capsules in aiereba and orinocensis); lateral stay of synarcual cartilage long, exceeding the lateral level of anterior ventral condyle (vs. short and not exceeding the lateral level of anterior ventral condyle in aiereba and orinocensis); dorsolateral crest of scapular process not pronounced and not exceeding laterally the level of mesocondyle (vs. pronounced dorsolateral crests that laterally exceed the level of mesocondyle in aiereba and orinocensis); propterygium robust (vs. more slender in aiereba and orinocensis); concavity of the internal face of mesopterygium not so pronounced and curved (vs. very pronounced and curved in aiereba and orinocensis); metapterygium robust and highly curved (vs. metapterygium slender and more straight in aiereba and orinocensis) (Ref. 125391).
Biology: 
IUCN Red List Status: Not Evaluated (N.E.) Ref. (130435)
Threat to humans:  harmless


Source and more info: www.fishbase.org. For personal, classroom, and other internal use only. Not for publication.