265: TRIACANTHODIDAE (SPIKEFISHES)
Family revised by Tyler (1968); additional species recorded
from western Indian Oce,!n by Tyler (1970; 1983), Hulley
(1972), Benbow (1974) and Matsuura (1982). Pelvic width
is distance between bases of the pelvic fin spines.
KEY TO GENERA
I a Snout equal to or shorter than eye diameter ............................ 2
I b Snout tubular. much longer than rest of head .......................... 7
2a Teeth conical, sharply pointed to bluntly rounded distally;
lips neither especially large nor swollen and spongy .................. 3
2b Teeth compressed, wider than thick, truncated
distally; lips large, swollen, spongy........................... Tydemania
3a Jaws with a major outer series of teeth and 1-6
isolated inner teeth (a few T. ethiops lack inner
teeth); pseudobranch lamellae 27-48, the
ventralmost at a level well below P base ...... : .......... Triacanthodes
3b Jaws with I series of teeth (no inner teeth); pseudobranch
lamellae 11-24, the ventralmost at a level above lower
edge of P base .................................................................. 4
4a 0 spines decreasing in length gradually, the last spine
small but easily seen .......................................................... 5
4b Posterior 0 spines much smaller than anterior spines; 4th
spine protruding through skin and slightly longer than
5th and 6th, which either protrude slightly or are
completely buried ............................................................. 6
5a Gill opening 13-15% SL (2 specimens), reaching
to slightly below P base ............................................ Mephisto
5b Gill opening 5-8% SL, not reaching below
P base ....................................................... Paratriacanthodes
6a Pelvic width 4-6 in its length; snout about equal
to postorbital distance (from eye to upper end
of gill opening); 5th and 6th 0 spines difficult
to see; profile of head either straight or slightly
convex; 1st 0 spine reaches tip of 4th spine .......... Atrophacanthus
6b Pelvic width 1.9-2.6 in its length; snout longer
than postorbital distance; 5th and 6th 0 spines
easily seen; profile of head more or less concave
before eyes; depressed 1st 0 spine reaches tip
of 6th spine ....................................................... Bathyphylax
7a Mouth about twice width of snout immediately
behind it, twisted to right or left, except in
some small specimens; lower jaw teeth
compressed, much wider than thick, easily seen;
upper jaw teeth 0-4, smaller and narrower than
lower teeth; 3rd 0 spine 0.6-0. 7 length of
2nd ....................................................... Macrorhamphosodes
7b Mouth not much wider than snout immediately
behind it and not twisted to one side; teeth
conical, small and difficult to see; 3rd 0 spine
less than )S length of 2nd spine ......................... Halimochirurgus
Genus Atrophacanthus Fraser-Brunner, 1950
One species, A. japonicus (Kamohara, 1941) known
from Japan, Philippines, Celebes Sea and off Tanzania;
possibly occurs in our area.
888
Genus 8athyphy/ax Myers, 1934
Two species: B. bombifrons Myers, 1934 (from Hong
Kong) and B. omen Tyler, 1966; both species have been
found off Kenya (Tyler, 1983) and may occur in our area. In
B. bombifrons the dorsal snout profile is distinctly concave;
in B. omen the dorsal snout profile is straight or slightly concave.
Genus Halimochirurgus Alcock, 1899
Snout greatly elongated and tubular; mouth supraterminat. Two species, both found off Kenya (Tyler, 1983) and
possibly in our area.
KEY TO SPECIES
la Mouth slightly wider than snout immediately
behind it, its width subequal to least interorbital width; postorbital distance about 0.7
of eye diameter; gill opening extends to below
P base, its length about 1.5 in eye diameter;
pelvic width about 4 in its length ....... H. centriscoides Alcock, 1899
(Indonesia to east Africa)
I b Mouth of same width as snout immediately
behind it, its width about )S or less of least
interorbital width; postorbital distance about
)S of eye diameter; gill opening not extending
below P base, its length about 2.5-3 in eye
diameter; pelvic width about 6 in its
length ................................................ H. alcocki Weber, 1913
(Japan to east Africa)
Genus Macrorhamphosodes Fowler, 1934
Highly specialised spikefishes with 1st 3 D spines well
developed, the last 3 barely visible; pelvis flat ventrally, its
width about 5-6 in its length; snout long and tubular; mouth
twisted to right or left, much wider than snout behind it.
Two species: M. platycheilus is known from Kenya (Tyler,
1983) and is likely to be found in our area.
KEY TO SPECIES
la Gill opening not extending below middle of P
base, its length about 3.5-4 in eye diameter; 2
well-developed teeth in upper jaw of adults, 4
in young; lower jaw teeth 12-16, sharply
pointed in young but rounded to slightly truncated
in adults; P (including small uppermost element)
14-15; 0 13-15 ....................................................... M. uradoi
I b Gill opening extending below middle of P
base, its length about 2-2.5 in eye diameter;
no teeth in upper jaw of adults, a few barely
protruding rudiments in young; lower jaw
teeth more than 20 in all (young with 17-19);
teeth slightly rounded distally in young, but
decidedly truncate in adults; P 11-13;
012-\3 ........................................ M. platycheilus Fowler, 1934
(Philippines to Kenya)
Family revised by Tyler (1968); additional species recorded
from western Indian Oce,!n by Tyler (1970; 1983), Hulley
(1972), Benbow (1974) and Matsuura (1982). Pelvic width
is distance between bases of the pelvic fin spines.
KEY TO GENERA
I a Snout equal to or shorter than eye diameter ............................ 2
I b Snout tubular. much longer than rest of head .......................... 7
2a Teeth conical, sharply pointed to bluntly rounded distally;
lips neither especially large nor swollen and spongy .................. 3
2b Teeth compressed, wider than thick, truncated
distally; lips large, swollen, spongy........................... Tydemania
3a Jaws with a major outer series of teeth and 1-6
isolated inner teeth (a few T. ethiops lack inner
teeth); pseudobranch lamellae 27-48, the
ventralmost at a level well below P base ...... : .......... Triacanthodes
3b Jaws with I series of teeth (no inner teeth); pseudobranch
lamellae 11-24, the ventralmost at a level above lower
edge of P base .................................................................. 4
4a 0 spines decreasing in length gradually, the last spine
small but easily seen .......................................................... 5
4b Posterior 0 spines much smaller than anterior spines; 4th
spine protruding through skin and slightly longer than
5th and 6th, which either protrude slightly or are
completely buried ............................................................. 6
5a Gill opening 13-15% SL (2 specimens), reaching
to slightly below P base ............................................ Mephisto
5b Gill opening 5-8% SL, not reaching below
P base ....................................................... Paratriacanthodes
6a Pelvic width 4-6 in its length; snout about equal
to postorbital distance (from eye to upper end
of gill opening); 5th and 6th 0 spines difficult
to see; profile of head either straight or slightly
convex; 1st 0 spine reaches tip of 4th spine .......... Atrophacanthus
6b Pelvic width 1.9-2.6 in its length; snout longer
than postorbital distance; 5th and 6th 0 spines
easily seen; profile of head more or less concave
before eyes; depressed 1st 0 spine reaches tip
of 6th spine ....................................................... Bathyphylax
7a Mouth about twice width of snout immediately
behind it, twisted to right or left, except in
some small specimens; lower jaw teeth
compressed, much wider than thick, easily seen;
upper jaw teeth 0-4, smaller and narrower than
lower teeth; 3rd 0 spine 0.6-0. 7 length of
2nd ....................................................... Macrorhamphosodes
7b Mouth not much wider than snout immediately
behind it and not twisted to one side; teeth
conical, small and difficult to see; 3rd 0 spine
less than )S length of 2nd spine ......................... Halimochirurgus
Genus Atrophacanthus Fraser-Brunner, 1950
One species, A. japonicus (Kamohara, 1941) known
from Japan, Philippines, Celebes Sea and off Tanzania;
possibly occurs in our area.
888
Genus 8athyphy/ax Myers, 1934
Two species: B. bombifrons Myers, 1934 (from Hong
Kong) and B. omen Tyler, 1966; both species have been
found off Kenya (Tyler, 1983) and may occur in our area. In
B. bombifrons the dorsal snout profile is distinctly concave;
in B. omen the dorsal snout profile is straight or slightly concave.
Genus Halimochirurgus Alcock, 1899
Snout greatly elongated and tubular; mouth supraterminat. Two species, both found off Kenya (Tyler, 1983) and
possibly in our area.
KEY TO SPECIES
la Mouth slightly wider than snout immediately
behind it, its width subequal to least interorbital width; postorbital distance about 0.7
of eye diameter; gill opening extends to below
P base, its length about 1.5 in eye diameter;
pelvic width about 4 in its length ....... H. centriscoides Alcock, 1899
(Indonesia to east Africa)
I b Mouth of same width as snout immediately
behind it, its width about )S or less of least
interorbital width; postorbital distance about
)S of eye diameter; gill opening not extending
below P base, its length about 2.5-3 in eye
diameter; pelvic width about 6 in its
length ................................................ H. alcocki Weber, 1913
(Japan to east Africa)
Genus Macrorhamphosodes Fowler, 1934
Highly specialised spikefishes with 1st 3 D spines well
developed, the last 3 barely visible; pelvis flat ventrally, its
width about 5-6 in its length; snout long and tubular; mouth
twisted to right or left, much wider than snout behind it.
Two species: M. platycheilus is known from Kenya (Tyler,
1983) and is likely to be found in our area.
KEY TO SPECIES
la Gill opening not extending below middle of P
base, its length about 3.5-4 in eye diameter; 2
well-developed teeth in upper jaw of adults, 4
in young; lower jaw teeth 12-16, sharply
pointed in young but rounded to slightly truncated
in adults; P (including small uppermost element)
14-15; 0 13-15 ....................................................... M. uradoi
I b Gill opening extending below middle of P
base, its length about 2-2.5 in eye diameter;
no teeth in upper jaw of adults, a few barely
protruding rudiments in young; lower jaw
teeth more than 20 in all (young with 17-19);
teeth slightly rounded distally in young, but
decidedly truncate in adults; P 11-13;
012-\3 ........................................ M. platycheilus Fowler, 1934
(Philippines to Kenya)