Classification / Names
Common names | Synonyms | Catalog of Fishes(genus, species) | ITIS | CoL | WoRMS | Cloffa
Elasmobranchii (sharks and rays) > Myliobatiformes
(Stingrays) > Potamotrygonidae
(River stingrays) > Potamotrygoninae
Etymology: Potamotrygon: Greek, potamos = river + Greek, trygon = a sting ray (Ref. 45335); rex: Name from Latin 'rex' meaning king; referring to its large, bulky size and striking color pattern, king of the rio Tocantins Potamotrygon species; noun in apposition.
Environment: milieu / climate zone / depth range / distribution range
Freshwater; benthopelagic. Tropical
South America: Rio Tocantins, Brazil.
Size / Weight / Age
Maturity: Lm ?  range ? - ? cm
Max length : 75.0 cm WD male/unsexed; (Ref. 115938)
Reported stomach contents in this species include fishes, insects and insect larvae, mollusks, and crustaceans, with predominance of insect larvae. Ontogenetic dietary shifts occur in species of this genus. Sexual maturity for males at about 58.0 cm TL (37.5 cm DL, 35.6 cm DW, MZUSP 120369, claspers almost fully calcified). Specimens greater than 100 cm in TL can easily weigh 20 kg. Great disparity in the largest sizes achieved by males and females (Ref. 115938).
Life cycle and mating behavior
Maturity | Reproduction | Spawning | Eggs | Fecundity | Larvae
Carvalho, M.R., 2016. Potamotrygon rex, a new species of Neotropical freshwater stingray (Chondrichthyes: Potamotrygonidae) from the middle and upper rio Tocantins, Brazil, closely allied to Potamotrygon henlei (Castelnau, 1855). Zootaxa 4150(5):537-565. (Ref. 115938)
IUCN Red List Status (Ref. 123251)
Threat to humans
Common namesSynonymsMetabolismPredatorsEcotoxicologyReproductionMaturitySpawningSpawning aggregationFecundityEggsEgg development
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingNutrientsMass conversion
Estimates based on models
Phylogenetic diversity index (Ref. 82805
= 0.5000 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01000 (0.00244 - 0.04107), b=3.04 (2.81 - 3.27), in cm total length, based on all LWR estimates for this body shape (Ref. 93245
Trophic level (Ref. 69278
): 3.2 ±0.4 se; based on size and trophs of closest relatives
Vulnerability (Ref. 59153
): High to very high vulnerability (70 of 100) .