247: GEMPYLIDAE (SNAKE MACKERELS)
3a C peduncle with a prominent lateral keel and 2
small supplemental keels above and below;
O2 8-11; LL single, markedly sinuous .................. Lepidocybium
3b No prominent keels on C peduncle, 0 1 more
than 12; LL simple, single or bifurcated, but not
markedly sinuous ............................................................ 4
4a Skin very rough; scales interspersed with spinous
bony tubercles; midventral keel on belly; LL
obscure ................................................................ Ruvettus
4b Body smooth; scales small, cycloid; no spiny tubercles;
no keel on belly; LL single or double and well developed ......... 5
5a V rudimentary (I,0-4) or absent .......................................... 6
5b V well developed (I,5) .................... . .............. ... ................ 9
6a LL single ....................................................................... 7
6b LL double ...................................................... ................ 8
7a A dagger-shaped spine followed by a minute
free spine almost embedded in front of A;
LL fairly straight ......................... Nealotus tripes Johnson, 1865
(Worldwide species known from off Kenya)
7b No free spines in front of A;
LL curved abruptly downward
anteriorly ................ Promethichthys prometheus (Cuvier, 1831)
(Worldwide species known from Comores)
8a Body about 5.5 times longer than head; 0 1 26-32;
0& A finlets 5-7; both LLs begin at upper edge
of opercle ........................................................... Gempylus
8b Body about 3.5 times longer than head; 0 1
17-18,0 & A finlets 2; lower LL branches off
under 4-6th 0 spines .................................................. Rexea
9a LL double ........................................................... .. ....... 10
9b LL single .................................................... .. .... .. ..... ..... 11
lOa 0 1 17-19; dermal flaps on jaws; lower LL runs
along middle of body; mouth and gill cavities
not black ......................................................... Thyrsitoides
lOb 0 1 16; no dermal flaps on jaws; lower LL runs
near ventral contour; mouth and gill cavities
black ............................................................. Neoepinnula
11a Dermal flaps on tip of jaws; LL
fairly straight; O2 (20-21)+(2-3);
A II,(l6-20)+(2-3); P 13 ......... Nesiarchus nasutus Johnson, 1862
(Worldwide species known from Gulf of Guinea)
lIb No dermal flap on tip of jaws; LL abruptly
bent below posterior 0 spines; O2 (10-12)+(5-7);
A II-III,(8-11)+(5-7); P 14-15 .................................. Thyrsites
247.1 Diplospinus multistriatus: 34 cm SL (drawn after Nakamura).
247.2 Gempylus serpens: 100 cm (west Africa).
826
Genus Dip/ospinus Maul, 1948
Karrer (1975) put Paradiplospinus gracilis in this genus,
otherwise 1 species.
247.1 Diplospinus multistriatus
Maul,1948
Diplospinus multistriatus Maul, 1948: 42, Fig. 17 (Madeira); Karrer,
1975: 74; Mikhaylin, 1976: 321; 1983: 13-19.
o XXX-XXXVI/35-42; A II,28-34; P 11-13. Vertebrae 57-61. Head
5.3-6.0 in SL. Body very elongate and compressed; depth 13-18 in SL. LL
single (or double ?) but easily removed. Anterior part of A very low. V
reduced to a minute spine in adults. Soft 0 base about Yz that of spinous O.
Attains 25 cm SL. Reported from 3 major oceans; in our
area known only off Namibia.
Genus Gempy/us Cuvier, 1829
Acinacea Bory de Saint-Vincent, 1804 was mistakenly
substituted for this genus by Whitley (1951), but it is a
nomen oblitum. One species.
247.2 Gempylus serpens
Cuvier, 1829
Snake mackerel
Siangmakriel
Gempylus serpens Cuvier, 1829: 20 (Jamaica); Smith, SFSA No. 864*;
Parin & Bekker, 1972: 151 *.
o XXVI-XXXII/I-II, 10-13 + 5-7 finlets; A II,I, 10-12 + 5-7 finlets; P
12-15; V I ,3-4. Body very elongate and compressed; depth about 15 in SL.
LL bifurcated; both branches originating below 1st 0 spine; upper LL
running near 0 to last spine; lower branch along midside to C. V minute.
Attains 1 m. Worldwide in tropical and SUbtropical
waters; sometimes in temperate latitudes.
Genus Lepidocybium Gill, 1863
Xenogramma Waite, 1904 is a junior synonym. One
species.
3a C peduncle with a prominent lateral keel and 2
small supplemental keels above and below;
O2 8-11; LL single, markedly sinuous .................. Lepidocybium
3b No prominent keels on C peduncle, 0 1 more
than 12; LL simple, single or bifurcated, but not
markedly sinuous ............................................................ 4
4a Skin very rough; scales interspersed with spinous
bony tubercles; midventral keel on belly; LL
obscure ................................................................ Ruvettus
4b Body smooth; scales small, cycloid; no spiny tubercles;
no keel on belly; LL single or double and well developed ......... 5
5a V rudimentary (I,0-4) or absent .......................................... 6
5b V well developed (I,5) .................... . .............. ... ................ 9
6a LL single ....................................................................... 7
6b LL double ...................................................... ................ 8
7a A dagger-shaped spine followed by a minute
free spine almost embedded in front of A;
LL fairly straight ......................... Nealotus tripes Johnson, 1865
(Worldwide species known from off Kenya)
7b No free spines in front of A;
LL curved abruptly downward
anteriorly ................ Promethichthys prometheus (Cuvier, 1831)
(Worldwide species known from Comores)
8a Body about 5.5 times longer than head; 0 1 26-32;
0& A finlets 5-7; both LLs begin at upper edge
of opercle ........................................................... Gempylus
8b Body about 3.5 times longer than head; 0 1
17-18,0 & A finlets 2; lower LL branches off
under 4-6th 0 spines .................................................. Rexea
9a LL double ........................................................... .. ....... 10
9b LL single .................................................... .. .... .. ..... ..... 11
lOa 0 1 17-19; dermal flaps on jaws; lower LL runs
along middle of body; mouth and gill cavities
not black ......................................................... Thyrsitoides
lOb 0 1 16; no dermal flaps on jaws; lower LL runs
near ventral contour; mouth and gill cavities
black ............................................................. Neoepinnula
11a Dermal flaps on tip of jaws; LL
fairly straight; O2 (20-21)+(2-3);
A II,(l6-20)+(2-3); P 13 ......... Nesiarchus nasutus Johnson, 1862
(Worldwide species known from Gulf of Guinea)
lIb No dermal flap on tip of jaws; LL abruptly
bent below posterior 0 spines; O2 (10-12)+(5-7);
A II-III,(8-11)+(5-7); P 14-15 .................................. Thyrsites
247.1 Diplospinus multistriatus: 34 cm SL (drawn after Nakamura).
247.2 Gempylus serpens: 100 cm (west Africa).
826
Genus Dip/ospinus Maul, 1948
Karrer (1975) put Paradiplospinus gracilis in this genus,
otherwise 1 species.
247.1 Diplospinus multistriatus
Maul,1948
Diplospinus multistriatus Maul, 1948: 42, Fig. 17 (Madeira); Karrer,
1975: 74; Mikhaylin, 1976: 321; 1983: 13-19.
o XXX-XXXVI/35-42; A II,28-34; P 11-13. Vertebrae 57-61. Head
5.3-6.0 in SL. Body very elongate and compressed; depth 13-18 in SL. LL
single (or double ?) but easily removed. Anterior part of A very low. V
reduced to a minute spine in adults. Soft 0 base about Yz that of spinous O.
Attains 25 cm SL. Reported from 3 major oceans; in our
area known only off Namibia.
Genus Gempy/us Cuvier, 1829
Acinacea Bory de Saint-Vincent, 1804 was mistakenly
substituted for this genus by Whitley (1951), but it is a
nomen oblitum. One species.
247.2 Gempylus serpens
Cuvier, 1829
Snake mackerel
Siangmakriel
Gempylus serpens Cuvier, 1829: 20 (Jamaica); Smith, SFSA No. 864*;
Parin & Bekker, 1972: 151 *.
o XXVI-XXXII/I-II, 10-13 + 5-7 finlets; A II,I, 10-12 + 5-7 finlets; P
12-15; V I ,3-4. Body very elongate and compressed; depth about 15 in SL.
LL bifurcated; both branches originating below 1st 0 spine; upper LL
running near 0 to last spine; lower branch along midside to C. V minute.
Attains 1 m. Worldwide in tropical and SUbtropical
waters; sometimes in temperate latitudes.
Genus Lepidocybium Gill, 1863
Xenogramma Waite, 1904 is a junior synonym. One
species.