5: SQUALIDAE (DOGFISHES)
5.7 Centroscymnus obscurus: 59 cm female (NW Africa; after Vaillant. 1888). T & d (from 62 cm specimen from Natal) as in 2.1.
5.7 Centroscymnus obscurus
Vaillant, 1888
Centroscymnus obscurus Vaillant, 1888: 67, PI. 2, Fig. 2 (off north-west
Africa). Scymnodon ?obscurus: Bass et aI., 1976: 35*.
Snout length subequal to mouth width; P distinctly longer than V.
Colour blackish. Attains 88 cm? Northwest Africa,
Madeira, Iceland-Faroe Rise and southern Brazil. South
African record based on 4 semi-digested sharks from the
stomach of a sperm whale killed off Durban.
Genus Deania Jordan & Snyder, 1902
Head depressed; body and caudal peduncle compressed.
Teeth unicuspid, dissimilar in upper and lower jaws; cusps
of lower teeth in adult males erect, those of females and
juveniles more oblique. Denticles erect, shaped like a
three-pronged pitchfork, sometimes with smaller accessory
cusps on the prongs. Snout long and flattened, its length in
front of mouth more than 50% of head length (to level of P
origins). Probably only 3 wide-ranging species; all 3 are
found in our area. The shape of the snout, teeth and dentic1es varies considerably within each species.
01J1:]J
~
T
5.8 Deania calceus: 84 cm male (off Algoa Bay). N, T & d as in 2.1.
KEY TO SPECIES
1a Low flap of skin along ventral midline behind V;
length of 1st D base usually somewhat less than distance
between D bases ........................................... D. profundorum
1b No midventral flap behind V; 1st D base either longer
or much shorter than distance between D bases ....................... 2
2a Distance from origin of exposed part of 1 st
D spine to tip of fin reaches from tip of fin past origin
of 2nd D spine; distance between D bases less than that
from snout tip to mouth ........................................... D. ca/ceus
2b Distance from origin of 1st D spine to tip of fin
reaches from tip of fin to a point well in front of
2nd D spine; distance between D bases more than snout
length ....................................................... D. quadrispinosus
5.8 Deania calceus
(Lowe, 1839)
Acanthidium ca/ceus Lowe, 1839: 92 (off Madeira). Deania ca/cea: Bass
et aI., 1976: 36*.
First D height 2.5-4.0 in distance from spine to rear end of base; interdorsal distance 9-14% TL; adpressed P falls short of vertical through 1st D
spine by a distance equal to interorbital space.
Grey-brownish. Males mature at 75-80 cm; attains 111
cm. Eastern North Atlantic, New Zealand and Japan; reported from west of Cape Point and off Algoa Bay in depths
of 400 - 500 m.
f
"
53
5.7 Centroscymnus obscurus: 59 cm female (NW Africa; after Vaillant. 1888). T & d (from 62 cm specimen from Natal) as in 2.1.
5.7 Centroscymnus obscurus
Vaillant, 1888
Centroscymnus obscurus Vaillant, 1888: 67, PI. 2, Fig. 2 (off north-west
Africa). Scymnodon ?obscurus: Bass et aI., 1976: 35*.
Snout length subequal to mouth width; P distinctly longer than V.
Colour blackish. Attains 88 cm? Northwest Africa,
Madeira, Iceland-Faroe Rise and southern Brazil. South
African record based on 4 semi-digested sharks from the
stomach of a sperm whale killed off Durban.
Genus Deania Jordan & Snyder, 1902
Head depressed; body and caudal peduncle compressed.
Teeth unicuspid, dissimilar in upper and lower jaws; cusps
of lower teeth in adult males erect, those of females and
juveniles more oblique. Denticles erect, shaped like a
three-pronged pitchfork, sometimes with smaller accessory
cusps on the prongs. Snout long and flattened, its length in
front of mouth more than 50% of head length (to level of P
origins). Probably only 3 wide-ranging species; all 3 are
found in our area. The shape of the snout, teeth and dentic1es varies considerably within each species.
01J1:]J
~
T
5.8 Deania calceus: 84 cm male (off Algoa Bay). N, T & d as in 2.1.
KEY TO SPECIES
1a Low flap of skin along ventral midline behind V;
length of 1st D base usually somewhat less than distance
between D bases ........................................... D. profundorum
1b No midventral flap behind V; 1st D base either longer
or much shorter than distance between D bases ....................... 2
2a Distance from origin of exposed part of 1 st
D spine to tip of fin reaches from tip of fin past origin
of 2nd D spine; distance between D bases less than that
from snout tip to mouth ........................................... D. ca/ceus
2b Distance from origin of 1st D spine to tip of fin
reaches from tip of fin to a point well in front of
2nd D spine; distance between D bases more than snout
length ....................................................... D. quadrispinosus
5.8 Deania calceus
(Lowe, 1839)
Acanthidium ca/ceus Lowe, 1839: 92 (off Madeira). Deania ca/cea: Bass
et aI., 1976: 36*.
First D height 2.5-4.0 in distance from spine to rear end of base; interdorsal distance 9-14% TL; adpressed P falls short of vertical through 1st D
spine by a distance equal to interorbital space.
Grey-brownish. Males mature at 75-80 cm; attains 111
cm. Eastern North Atlantic, New Zealand and Japan; reported from west of Cape Point and off Algoa Bay in depths
of 400 - 500 m.
f
"
53