Order TORPEDINIFORMES
Electric rays
Batoids with pectoral fins greatly expanded and fused
with head and trunk, forming a large, oval disc. A pair of
unique, kidney-shaped electric organs in front of disc,
usually visible through skin as pattern of hexagonal markings. The electric organs can produce a powerful and
dangerous electric shock when these rays are disturbed .
Dorsal fin(s) present or absent; tail thick but short; caudal
fin functional in swimming. Adults about 10-183 cm.
Ovoviviparous. Circumtropical and temperate inshore to
deep-water benthic batoids. Two or 4 families , depending
on the classification used; 11 genera and 42 species.
Family No. 23: TORPEDINIDAE
by L.J.V. Compagno
Electric rays
Drilvisse
Head , body and pectoral fins form a rounded, soft and
flabby disc, usually slightly wider than long. Electric rays
(Torpedinidae, Narkidae and 2 extralimital families) are
unique in having 2 large, kidney-shaped electric organs in
the disc on either side of the head. These organs are capable
of generating strong electric shocks which are administered
al will. Nasal flaps form broad , short nasal curtain ; mouth
broadly arched. Five pairs of gill openings on underside of
disc. Jaws with small cuspidate teeth. Two moderate-sized
dorsal fins and a large caudal fin present ; tail short and
strong.
Small to moderately large batoid fishes, largest possibly
over 2 m long. Large pectoral fins are not used for swimming; fish is slowly propelled by caudal pedunde and caudal
fin. Electric rays stun both small and large fishes on bottom
or in midwater with shocks, and can jolt the unwary angler,
trawlerman or swimmer that encounters them . Worldwide
in all tropical and temperate seas, inshore and in deep water
near the bottom . One genus, Torpedo Houttuyn , 1764 with
several species, 3 in our area.
KEY TO SPECIES
la Margins of spiracles smooth ; C height about equal
to distance from upper C origin to first D origin ......... T. nobiliana
I b Margin of spiracles with short tentacles or papillae ;
C height much less than distance from upper C origin
to first D origin .......... .. .. .. .. .. ..... ....... .. ... ..... ...... ...... .. ... ...... 2
2a Dorsal surface grey , uniform or with numerous white
fl ecks or pale to dark brown spots .. .. ....... ...... .... T. Juscomaculata
2b Dorsal surface bright red or brown , with pale
reticulated pattern ..... .. .......... ............ .. ....... .. .... T. sinuspersici
112
23.1 Torpedo fuscomaculata
Peters, 1855
PLATE 5
Drilvisse
Blackspotted electric ray
Swartspikkel-drilvis
Torpedo Juscomaculata Peters, 1855: 278 (Mozambique); Smith &
Smith , 1966: 34*; Wallace , 1967: 49*. Torpedosmithii Gunther, 1870: 451
(South Africa). Torpedo marmorata: (non Risso, 1810): Smith, SFSA
No. 91* (Fig. only) ; Smith & Smith , 1966: 34*.
Greyish , dull-coloured in comparison to T. sinuspersici.
Attains 64 cm TL. Knysna to southern Mozambique in 64 -
439 m; also Seychelles, Mauritius, Madagascar and Zanzibar. Not very common.
23.2 Torpedo nobiliana
Bonaparte, 1835
Atlantic electric ray
Atlantiese drilvis
Torpedo nobiliana Bonaparte, 1835: Fig. (pp. not numbered; Italy) ;
Barnard , 1925: 89; Smith, SFSA No. 92.
Uniformly dark chocolate or purplish brown to black
above, white below. Attains at least 122 cm TL in our area,
to at least 180 cm elsewhere. Western North Atlantic,
Mediterranean Sea and eastern Atlantic; western Cape
coast to Algoa Bay, in 110 - 457 m. Trawl-caught rays are
usually exhausted and incapable of powerful shocks, but
can deliver up to 220 volts when rested.
" .
,
23.2 Torpedo nobiliana: 30.5 em wide female (off Orange River), dorsal view .
Electric rays
Batoids with pectoral fins greatly expanded and fused
with head and trunk, forming a large, oval disc. A pair of
unique, kidney-shaped electric organs in front of disc,
usually visible through skin as pattern of hexagonal markings. The electric organs can produce a powerful and
dangerous electric shock when these rays are disturbed .
Dorsal fin(s) present or absent; tail thick but short; caudal
fin functional in swimming. Adults about 10-183 cm.
Ovoviviparous. Circumtropical and temperate inshore to
deep-water benthic batoids. Two or 4 families , depending
on the classification used; 11 genera and 42 species.
Family No. 23: TORPEDINIDAE
by L.J.V. Compagno
Electric rays
Drilvisse
Head , body and pectoral fins form a rounded, soft and
flabby disc, usually slightly wider than long. Electric rays
(Torpedinidae, Narkidae and 2 extralimital families) are
unique in having 2 large, kidney-shaped electric organs in
the disc on either side of the head. These organs are capable
of generating strong electric shocks which are administered
al will. Nasal flaps form broad , short nasal curtain ; mouth
broadly arched. Five pairs of gill openings on underside of
disc. Jaws with small cuspidate teeth. Two moderate-sized
dorsal fins and a large caudal fin present ; tail short and
strong.
Small to moderately large batoid fishes, largest possibly
over 2 m long. Large pectoral fins are not used for swimming; fish is slowly propelled by caudal pedunde and caudal
fin. Electric rays stun both small and large fishes on bottom
or in midwater with shocks, and can jolt the unwary angler,
trawlerman or swimmer that encounters them . Worldwide
in all tropical and temperate seas, inshore and in deep water
near the bottom . One genus, Torpedo Houttuyn , 1764 with
several species, 3 in our area.
KEY TO SPECIES
la Margins of spiracles smooth ; C height about equal
to distance from upper C origin to first D origin ......... T. nobiliana
I b Margin of spiracles with short tentacles or papillae ;
C height much less than distance from upper C origin
to first D origin .......... .. .. .. .. .. ..... ....... .. ... ..... ...... ...... .. ... ...... 2
2a Dorsal surface grey , uniform or with numerous white
fl ecks or pale to dark brown spots .. .. ....... ...... .... T. Juscomaculata
2b Dorsal surface bright red or brown , with pale
reticulated pattern ..... .. .......... ............ .. ....... .. .... T. sinuspersici
112
23.1 Torpedo fuscomaculata
Peters, 1855
PLATE 5
Drilvisse
Blackspotted electric ray
Swartspikkel-drilvis
Torpedo Juscomaculata Peters, 1855: 278 (Mozambique); Smith &
Smith , 1966: 34*; Wallace , 1967: 49*. Torpedosmithii Gunther, 1870: 451
(South Africa). Torpedo marmorata: (non Risso, 1810): Smith, SFSA
No. 91* (Fig. only) ; Smith & Smith , 1966: 34*.
Greyish , dull-coloured in comparison to T. sinuspersici.
Attains 64 cm TL. Knysna to southern Mozambique in 64 -
439 m; also Seychelles, Mauritius, Madagascar and Zanzibar. Not very common.
23.2 Torpedo nobiliana
Bonaparte, 1835
Atlantic electric ray
Atlantiese drilvis
Torpedo nobiliana Bonaparte, 1835: Fig. (pp. not numbered; Italy) ;
Barnard , 1925: 89; Smith, SFSA No. 92.
Uniformly dark chocolate or purplish brown to black
above, white below. Attains at least 122 cm TL in our area,
to at least 180 cm elsewhere. Western North Atlantic,
Mediterranean Sea and eastern Atlantic; western Cape
coast to Algoa Bay, in 110 - 457 m. Trawl-caught rays are
usually exhausted and incapable of powerful shocks, but
can deliver up to 220 volts when rested.
" .
,
23.2 Torpedo nobiliana: 30.5 em wide female (off Orange River), dorsal view .