Elasmobranchii (sharks and rays) > Torpediniformes
(Electric rays) > Torpedinidae
Etymology: Torpedo: Latin, torpere = be sluggish (Ref. 45335).
Environment: milieu / climate zone / depth range / distribution range
Marine; brackish; reef-associated; depth range 2 - 370 m (Ref. 4430). Subtropical; ? - 20°C (Ref. 10011); 60°N - 34°S, 19°W - 36°E (Ref. 114953)
Eastern Atlantic: northern UK (less common in southern North Sea and Kattegat) to Cape of Good Hope, South Africa. Also in the Mediterranean Sea.
Length at first maturity / Size / Weight / Age
Maturity: Lm ?, range 39 - 49 cm
Max length : 100.0 cm TL male/unsexed; (Ref. 27000); common length : 60.0 cm TL male/unsexed; (Ref. 114953); max. published weight: 3.0 kg (Ref. 35388)
Morphology | Morphometrics
soft rays: 0;
Vertebrae: 104 - 108. Disc-width around the same as its length, length and width 1,50 to 1,70 times in total length; dorsal fins more or less rounded, its base 1,50 times in its height (Ref. 39215).
Occurs in seagrass areas, rocky reefs, and adjacent soft bottoms (Ref. 12951). Avoids temperatures above 20°C (Ref. 10011). Nocturnal, usually burying itself during the day with only the eyes and spiracle jutting out (Ref. 12382). Feeds on small benthic fishes Trachurus, Mugil, Mullus, Dicentrarchus, Spondyliosoma, Boops, Labrus, Dascyllus, Pomacentrus) and crustaceans (Ref. 10011). Females outlive males; viviparous, neonates measuring 10-14 cm at birth (Ref. 10426). Produces 2-32 pups in a litter after a 10-month gestation (Ref. 12951, Ref. 114953). Males reaches maturity at ca. 30 cm TL, females at ca. 40 cm TL; born at 10-14 cm TL (Ref. 114953). Electrocytes start developing when the embryo weighs about 1 g; electric organs functional before birth and newborns can use their electric organ discharge (EOD) in capturing prey (Ref. 10428). Can produce electric discharges of up to 200 volts; EOD frequency up to 600 Hz. Jumps on fast-moving prey, paralyzing it with its EOD (Ref. 27000).
Exhibit ovoviparity (aplacental viviparity), with embryos feeding initially on yolk, then receiving additional nourishment from the mother by indirect absorption of uterine fluid enriched with mucus, fat or protein through specialised structures (Ref. 50449).
Stehmann, M. and D.L. Bürkel, 1984. Torpedinidae. p. 159-162. In P.J.P. Whitehead, M.-L. Bauchot, J.-C. Hureau, J. Nielsen and E. Tortonese (eds.) Fishes of the north-eastern Atlantic and Mediterranean. UNESCO, Paris. Vol. 1. (Ref. 2803)
IUCN Red List Status (Ref. 119314)
CITES (Ref. 115941)
Fisheries: of no interest; aquarium: public aquariums
ReferencesAquacultureAquaculture profileStrainsGeneticsAllele frequenciesHeritabilityDiseasesProcessingMass conversion
Estimates of some properties based on models
Preferred temperature (Ref. 115969
): 10.1 - 19.2, mean 14.1 (based on 392 cells).
Phylogenetic diversity index (Ref. 82805
= 0.5005 [Uniqueness, from 0.5 = low to 2.0 = high].
Bayesian length-weight: a=0.01862 (0.01412 - 0.02456), b=2.94 (2.86 - 3.02), in cm Total Length, based on LWR estimates for this species (Ref. 93245
Trophic Level (Ref. 69278
): 4.5 ±0.0 se; Based on diet studies.
Resilience (Ref. 69278
): Low, minimum population doubling time 4.5 - 14 years (Fec=5-32).
Vulnerability (Ref. 59153
): High to very high vulnerability (69 of 100) .