Paratrygon

Paratrygon
Paratrygon aiereba at Shedd Aquarium, showing its underside and concave snout (to the right on photo)
Conservation status
Data Deficient  (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Chondrichthyes
Subclass:	Elasmobranchii
Order:	Myliobatiformes
Family:	Potamotrygonidae
Genus:	Paratrygon A. H. A. Duméril, 1865
Species:	P. aiereba
Binomial name
Paratrygon aiereba (Müller & Henle, 1841)

Paratrygon is a monotypic genus of the cartilaginous fish in the family of Potamotrygonidae. The sole currently recognized species is Paratrygon aiereba, the discus ray, manzana ray or ceja ray, from the Amazon and Orinoco basins in South American. Genetic evidence suggests that P. aiereba as presently defined is a species complex.

Appearance

This freshwater ray has small eyes and a disc shaped roughly like a lily pad (the snout is slightly concave). It is brownish above with a dark vermiculated or reticulated pattern. It reaches up to 1.6 m (5.2 ft) in disc width and 110 kg (240 lb) in weight, making it one of the largest species in the family. There are unconfirmed claims of much larger individuals, but these are considered highly questionable. Most individuals do not surpass a disc width of 1.3 m (4.3 ft). Males reach maturity at a disc width of about 60 cm (2.0 ft) and females at about 72 cm (2.4 ft).

Behavior

It mainly feeds on fish, but also take invertebrates such as insects and crustaceans, and it is a top predator in its habitat. Adults are found in relatively deep waters in main river channels, but move to shallower waters to feed at night. After a nine-month gestation, the female give birth to an average of two young with a disc width of about 16 cm (6.3 in). Juveniles are found in relatively shallow waters at sandy beaches and in creeks.