West African Torpedo Ray, Ringed Torpedo Ray, Mackay’s Torpedo Ray.
A small to medium-sized torpedo ray with a fairly thick circular disc that is slightly wider than long. Snout short. Anterior margin of disc almost straight in juveniles, somehat concave in adults, with a slightly protruding, central bulge. Pectoral fin apices evenly rounded. Eyes somewhat protruding, about the same size as, and well separated from spiracles. Spiracles smooth-edged; lacking papillae. Mouth arched. Nostrils with prominent nasal flaps. Electric organs more visible ventrally.
Pelvic fins relatively narrow, with angular apices and straight to slightly convex margins. Tail relatively long with a small lateral skin fold. Dorsal fins well separated; distance roughly equal to second dorsal base. First dorsal fin tall with broadly rounded apex and posterior margin. First dorsal origin over or slightly posterior to pelvic fin insertion. Second dorsal fin smaller and more slanted with a more narrowly rounded apex. Caudal fin large, sub-triangular, apices narrowly rounded, posterior margin slightly convex.
Dorsum greyish brown to reddish brown with many small white spots. Spots up to eye-sized in Juveniles, mostly concentrated centrally on disc. Adults with much smaller and more uniformly separated spots, reaching almost to disc margins. Spots in adults may be connected by diffuse fine lines that form an underlying honeycomb pattern, hence alternative common name ‘ringed torpedo ray’. Dorsal posterior margins pale. Ventrum off white.
Maximum length ~60cm.
The West African torpedo ray is caught in artisanal fisheries, but it is discarded in most countries; Senegal is a notable exception. Combined with sporadic incursions by larger scale international trawlers, Torpedo mackayana populations have been significantly depleted.
Sub-temperate to tropical seas. Benthic on soft sandy substrates. Reportedly 15-50m, but I have encountered many juveniles and at least one adult West African Torpedo Ray in N’gor Bay, Senegal, at 1m-4m right off the beach.
Eastern Atlantic. Senegal to Angola.
Poorly known but presumably aplacental viviparous. Numerous sightings of juveniles in extremely shallow water in Senegal suggests that gravid females may move into shallow bays to give birth.
Probably small benthic invertebrates.
Nocturnal; remains buried under sand during the day. Actively swims over the seabed in search of prey during the night.
Reaction to divers
Easy to approach but tends to start swimming away if uncovered or harassed. Eventually bolts or tries to re-bury if approached too aggressively. May try to shock divers when threatened.
There appears to be a nursery for West African Torpedo Rays in N’gor Bay in Senegal. In January 2024, I found between one and eight animals on every night dive. All but one were juveniles. They were extremely difficult to locate during the day.