* distinguished by disk shaped body, long thickset tail, and gills

* body is composed of a disk (head, trunk and pectoral fins )

* The ventral side (underside) is the location of the mouth and five pairs of gill slits.

* Attached at the posterior end is the tail. Along the dorsal side contains 1- 3 rows of highly poisonous serrated spines

* small pelvic fins on either sides of the anus

* Located behind the eyes are two spiracles. Spiracles are the 1st gill slits and the only ones located on the dorsal side.

* eyes are located dorsally

* The small mouth on the underside is incapable of opening widely and can only swallow a small bite.

* sheds its spines and replaces them approximately every 2- 3 months

* cartilaginous

* extremely small species ( varying not much more than 30 cm ( 12 in ) in size

* greatest defense mechanism is its ability to camouflage itself on the bottom of the river

* has spots and patterns varying with the species