Torpedinidae
by M. Stehmann and D. L. Burkel
Blunt-snouted rays of medium size (to 2 m TL), the disc, through greatly enlarged pectoral fins fused with sides of head, more or less circular, strongly depressed, but thick and fleshy towards its margins and more massive than in most other rays; snout short to extremely short, front margin emarginate or truncate; tail very massive, equal to or shorter than body, from which it is distinctly marked off. Spiracles close behind eyes, with smooth or tentaculated margins. Nostrils close to, but separate from mouth, their inner margins expanded and fused as a nasal flap reaching to the level of the mouth, which is small, curved and protractile; small, single-cusped teeth in bands, forming a pavement in both jaws. Two dorsal fins well developed, as also caudal fin. Skin soft and entirely naked (except in one species not found in area); two large and powerful electric organs, one on each side of head.
Benthic on soft bottoms in shallow coastal waters from temperate to tropical latitudes, locally common. Feeding on bottom invertebrates and fishes, often quite large; electric shocks of 10-220 volts used to stun prey, for defence and for sensory location. Ovoviviparous. Usually inactive on bottom, often buried in the substrate, sluggish when swimming. Occur singly or in groups, depending on species and/or growth stage.
Genus 1 (but up to 7 recognized by some authors).
Recent revisions: Bigelow and Schroeder (1953), Compagno (1973).