Pacific Torpedo Ray: Tetronarce californica

Family: Torpedinidae

Common name(s)

Pacific Torpedo Ray, California Torpedo Ray.

Identification

A very large torpedo ray with a broad sub-circular disc. Snout straight across or weakly convex. Pectoral fin apices broadly rounded. Eyes small; smaller than spiracles. Spiracles sub-oval without papillae or raised margins. Mouth strongly arched. Nostrils large and round.
Pelvic fins very wide, margins broadly rounded. Tail short and broad based. Dorsal fins tall with broadly rounded apices and posterior margins. First dorsal insertion level with pelvic fin insertion. Caudal fin sub-triangular and large, with tall dorsal and ventral lobes, apices narrowly rounded, posterior margin convex.

Colour

Dorsum and fins bluish grey to greyish brown, with scattered small black flecks. Ventrum white.

Size

Maximum length 137cm. Size at birth unknown.

Habitat

Temperate seas. Benthic on soft bottoms, and rocky reefs, sometimes within kelp forests, and on continental shelf. From 5-275m.

Distribution

Eastern and northwestern Pacific. In the eastern Pacific from Baja California to Haida Gwaii, British Columbia. Possibly also off Japan.

Conservation Status

LEAST CONCERN

The Pacific Electric Ray (Torpedo californica) is targeted for its electric organs by the biomedical industry in very low numbers, and is also bycatch in commercial fisheries. While the population trend for this particular species is unknown, landings data suggest that it is rarely encountered in commercial fisheries in north and central California, and recreational catch is limited. Little is known about this species biology and ecology, but it is estimated to have a generation time of 12.5 years. Given that landings of skates and rays are stable where data are available, and that this species appears to be relatively uncommon in reported landings, Pacific Torpedo is assessed as Least Concern throughout its range.

Citation

Neer, J.A., Freedman, R.M., Lowe, C.G & Jang, J.J. 2015. Tetronarce californica. The IUCN Red List of Threatened Species 2015: e.T39396A80672988. https://dx.doi.org/10.2305/IUCN.UK.2015-4.RLTS.T39396A80672988.en. Downloaded on 04 June 2021.

Reproduction

Aplacental viviparous. Litter size up to 17.

Diet

Diet consists exclusively of small fishes.

Behavior

The Pacific torpedo ray immobilizes prey by stunning them while buried under sand. It also hunts fishes in open water.
Moves inshore during the summer months.

Reaction to divers

Easy to approach. Even when encountered while free swimming, the Pacific torpedo ray is quite nonchalant when in close proximity to divers and may even bump into them.

Diving logistics

Although rarely encountered throughout much of its range, the Pacific torpedo ray is quite common around Catalina Island in Southern California. Animals are occasionally spotted at dive sites such as the shore dive at Casino Point right in Avalon, but the best spot to see this species is at Farnsworth Bank on the west side of the island. Unless you have your own boat, this is a difficult spot to reach because the weather has to be perfect to dive there so Catalina dive companies seldom go.