‘Numb, sluggish and lethargic’, the torpedo ray wasn’t named after the naval weapon but by the ancient Romans, whose physicians used them for some interesting treatments.
Torpedo rays are a group of electric rays in the family Torpedinidae, comprising 22 species spread across two genera, Torpedo and Tetronarce, the latter being larger and having smoother spiracles (body openings) than the former.
Torpedo rays are distributed globally, with the species pictured above – Torpedo panthera, or leopard torpedo – often encountered in the Red Sea, although so little is known of their populations that most species are listed as ‘data deficient’ by the International Union for Conservation of Nature.
Like other species of rays, torpedo ray females are ovoviviparous, producing eggs which hatch inside the body before birth. Unlike other rays, however, which use their ‘wings’ to swim, torpedo rays have caudal fins to propel themselves through the water like their distant shark cousins.
The name torpedo is not derived from the naval weapon (the origins of which probably referred to the fish, not the other way around), but was the name used by ancient Romans to refer to electric rays.
It is derived from the Latin torpere, meaning ‘to be numb, struck motionless, sluggish or lethargic’, presumably a reference to both the way the rays move and their ability to deliver an electric shock to stun their prey.
A torpedo ray’s electric shock is generated by modified muscles located on either side of its head. Most pose little threat to humans – in fact, Roman physicians used to shock patients with them as a treatment for headaches, gout and haemorrhoids.
The largest species, however, the Atlantic torpedo (Tetronarce nobiliana), can measure more than 1.5m in length and is capable of generating a charge of up to 220 volts, enough to knock a human unconscious.
