Family No. 69: ASTRONESTHIDAE
by R.H. Gibbs, Jr.
Snaggletooths
Lostandvisse
Body without scales or hexagonal areas; skin usually
black, sometimes iridescent silver on sides; 2 rows of
prominent photophores on ventral part of body on each
side, anterior section of ventral row (PV) curving upward to
pelvic fin insertion, not continuous with posterior part of
row (VAL); numerous small photophores on most of body
and head, most dense ventrally; dorsal fin mostly or entirely
in advance of anal fin, usually near middle of body length;
dorsal adipose fin present (absent in Rhadinesthes, which is
not found in the area); a prominent barbel arising under
chin, ranging from half to 3 times head length (rudimentary
in species of Astronesthes not found in the area), with or
without terminal bulb or swelling.
Snaggletooths occur in mid-depths of the open oceans
around the world, often migrating to near-surface or surface waters at night; some apparently benthopelagic as
adults. Five genera with a total of about 35 species; 3 genera
with 10 species described here. The revisions by Regan &
Trewavas (1929) and Gibbs (1964), are out of date in many
respects. Revisionary studies are being conducted by
Gibbs.
KEY TO GENERA
1a A rays 21-28; snout appearing upturned at tip;
gill bars with closely spaced needle-like spines
anteriorly along their length ........... ............ ..... .. ..... Neonesthes
1b A rays 12-21; snout not upturned; gill bars with separated
groups of short teeth anteriorly along their length ..................... 2
2a Teeth on maxilla comb-like, closely spaced,
slanting rearward ........... ..... ... .... ........ .... ...... ..... .. Astronesthes
2b Teeth on maxilla distinctly separated, not
slanting rearward ................. .................... .. ......... Borostomias
Genus Astronesthes Richardson, 1844
About 25 species; 6 probably in our area.
KEY TO SPECIES
1a Serial photophores few and relatively widely
spaced; OV 5-6; VAL 6-8; IP 4-6; PV 5-7;
VA V 7-9; AC 6-10 .... ............... .............................. A. indicus
1b Serial photophores numerous and closely spaced,
minimum numbers as follows: OV 11 , VAL 17, IP 8,
PV 12, VA V 18, AC 11 .......... ............................... .. ........... 2
2a Ventral row of photophores forming a
pronounced U-shaped bend at level of P ............... .... .. .. A. niger
2b Ventral row of photophores forming a straight
or only slightly curved line between P ............. .. .... ..... ......... ... 3
3a Middle photophores of AC row (above A)
raised above those at beginning and end of row;
sides of body silvery .... .. ... ... ... ..... .. ..... .... .... ........ .. A. martensii
69: ASTRONESTHIDAE (SNAGGLETOOTHS)
3b AC photophores forming a continuous line; body
entirely black ... .. .. ..... ...... ............... .. ... ... ..... ....... ....... ...... . 4
4a Distal end of barbel with long, slender swelling, without
filaments; Prays 7-9 (usually 8); Drays 13-17 (usually
13-15) ; OA photophores 39 or fewer ........ .... .. ....................... 5
4b Distal end of barbel with bulbous swelling with
2 side filaments and, usually , a terminal filament
or projection; P 6-7 (usually 6); D 11-12
(occasionally 13 or 14); OA photophores 40
or more ............ ... ..... ... ... ......... ................. .. .... A. trifibulatus
5a Pale patches of luminous material present on
dorsal and ventral C peduncle and other parts of
body in medium to large specimens (not visible
ill many small specimens); PV photophores 12-16;
V A V usually 20 or more ; OA usually 37 or fewer ... .. A. boulengeri
5b No pale patches on C peduncle or rest of body;
PV photophores 17-19; VA V usually 18 or 19;
OA usually 38 or more ..... .. ....... .... .......... ......... A. caulophorus
69.1 Astronesthes boulengeri
Gilchrist, 1902
Astronesthes boulengeri Gilchrist, 1902: 103, PI. 6 (southeast of Cape
Point) ; Parr, 1927: 37; Regan & Trewavas, 1929: 21*; Smith, SFSA No.
141; Gibbs, 1964: 316* .
D 13-17; A 12-18; P 7-9. Ventral row of serial photophores: IP 10-12,
PV 12-16, VA V 19-25, AC 11-15, total 53-62; lateral row of serial photophores: OV 13-17, VAL 19-25, total 34-38. Vertebrae 49-55. Barbel
slightly longer than, to less than , ~ head length , its tip barely widened in
some, forming a long, slender swelling in others .
Body black; pale luminous patches develop with growth
on dorsal and ventral C peduncle and other parts of body.
Attains 21 cm. Circumpolar between 30° and 40 0 S.
69.1 Astronesthes boulengeri: 21 cm holotype (after Gilchrist, 1902).
69.2 Astronesthes caulophorus
Regan & Trewavas, 1929
Astronesthes caulophorus Regan & Trewavas, 1929: 15, Fig. 3 (13°35'S,
30"11'W); Gibbs, 1964: 317. Astronesthes blanci Blache & Rossignol,
1961 : 282, Fig. (03°36'S, 09°12'E); Karrer, 1973: 207*; 1975: 68.
D 13-15 ; A 16-19; P 7-8. Ventral row of serial photophores: IP 10-11,
PV 17-19, VA V 18-20, AC 11-14, total 59-62; lateral row of serial photophores: OV 17-18, VAL 20-22, total 37-39. Vertebrae 53-56. Barbel
slightly longer than , to about 7) of head length, its tip forming a long,
slender swelling.
Body black, without pale luminous patches; head with
many small, pale dots developing with growth behind eye
and on gill cover. Attains 26 cm. Occurs only in tropical
Atlantic to about 20 0 S.
231
by R.H. Gibbs, Jr.
Snaggletooths
Lostandvisse
Body without scales or hexagonal areas; skin usually
black, sometimes iridescent silver on sides; 2 rows of
prominent photophores on ventral part of body on each
side, anterior section of ventral row (PV) curving upward to
pelvic fin insertion, not continuous with posterior part of
row (VAL); numerous small photophores on most of body
and head, most dense ventrally; dorsal fin mostly or entirely
in advance of anal fin, usually near middle of body length;
dorsal adipose fin present (absent in Rhadinesthes, which is
not found in the area); a prominent barbel arising under
chin, ranging from half to 3 times head length (rudimentary
in species of Astronesthes not found in the area), with or
without terminal bulb or swelling.
Snaggletooths occur in mid-depths of the open oceans
around the world, often migrating to near-surface or surface waters at night; some apparently benthopelagic as
adults. Five genera with a total of about 35 species; 3 genera
with 10 species described here. The revisions by Regan &
Trewavas (1929) and Gibbs (1964), are out of date in many
respects. Revisionary studies are being conducted by
Gibbs.
KEY TO GENERA
1a A rays 21-28; snout appearing upturned at tip;
gill bars with closely spaced needle-like spines
anteriorly along their length ........... ............ ..... .. ..... Neonesthes
1b A rays 12-21; snout not upturned; gill bars with separated
groups of short teeth anteriorly along their length ..................... 2
2a Teeth on maxilla comb-like, closely spaced,
slanting rearward ........... ..... ... .... ........ .... ...... ..... .. Astronesthes
2b Teeth on maxilla distinctly separated, not
slanting rearward ................. .................... .. ......... Borostomias
Genus Astronesthes Richardson, 1844
About 25 species; 6 probably in our area.
KEY TO SPECIES
1a Serial photophores few and relatively widely
spaced; OV 5-6; VAL 6-8; IP 4-6; PV 5-7;
VA V 7-9; AC 6-10 .... ............... .............................. A. indicus
1b Serial photophores numerous and closely spaced,
minimum numbers as follows: OV 11 , VAL 17, IP 8,
PV 12, VA V 18, AC 11 .......... ............................... .. ........... 2
2a Ventral row of photophores forming a
pronounced U-shaped bend at level of P ............... .... .. .. A. niger
2b Ventral row of photophores forming a straight
or only slightly curved line between P ............. .. .... ..... ......... ... 3
3a Middle photophores of AC row (above A)
raised above those at beginning and end of row;
sides of body silvery .... .. ... ... ... ..... .. ..... .... .... ........ .. A. martensii
69: ASTRONESTHIDAE (SNAGGLETOOTHS)
3b AC photophores forming a continuous line; body
entirely black ... .. .. ..... ...... ............... .. ... ... ..... ....... ....... ...... . 4
4a Distal end of barbel with long, slender swelling, without
filaments; Prays 7-9 (usually 8); Drays 13-17 (usually
13-15) ; OA photophores 39 or fewer ........ .... .. ....................... 5
4b Distal end of barbel with bulbous swelling with
2 side filaments and, usually , a terminal filament
or projection; P 6-7 (usually 6); D 11-12
(occasionally 13 or 14); OA photophores 40
or more ............ ... ..... ... ... ......... ................. .. .... A. trifibulatus
5a Pale patches of luminous material present on
dorsal and ventral C peduncle and other parts of
body in medium to large specimens (not visible
ill many small specimens); PV photophores 12-16;
V A V usually 20 or more ; OA usually 37 or fewer ... .. A. boulengeri
5b No pale patches on C peduncle or rest of body;
PV photophores 17-19; VA V usually 18 or 19;
OA usually 38 or more ..... .. ....... .... .......... ......... A. caulophorus
69.1 Astronesthes boulengeri
Gilchrist, 1902
Astronesthes boulengeri Gilchrist, 1902: 103, PI. 6 (southeast of Cape
Point) ; Parr, 1927: 37; Regan & Trewavas, 1929: 21*; Smith, SFSA No.
141; Gibbs, 1964: 316* .
D 13-17; A 12-18; P 7-9. Ventral row of serial photophores: IP 10-12,
PV 12-16, VA V 19-25, AC 11-15, total 53-62; lateral row of serial photophores: OV 13-17, VAL 19-25, total 34-38. Vertebrae 49-55. Barbel
slightly longer than, to less than , ~ head length , its tip barely widened in
some, forming a long, slender swelling in others .
Body black; pale luminous patches develop with growth
on dorsal and ventral C peduncle and other parts of body.
Attains 21 cm. Circumpolar between 30° and 40 0 S.
69.1 Astronesthes boulengeri: 21 cm holotype (after Gilchrist, 1902).
69.2 Astronesthes caulophorus
Regan & Trewavas, 1929
Astronesthes caulophorus Regan & Trewavas, 1929: 15, Fig. 3 (13°35'S,
30"11'W); Gibbs, 1964: 317. Astronesthes blanci Blache & Rossignol,
1961 : 282, Fig. (03°36'S, 09°12'E); Karrer, 1973: 207*; 1975: 68.
D 13-15 ; A 16-19; P 7-8. Ventral row of serial photophores: IP 10-11,
PV 17-19, VA V 18-20, AC 11-14, total 59-62; lateral row of serial photophores: OV 17-18, VAL 20-22, total 37-39. Vertebrae 53-56. Barbel
slightly longer than , to about 7) of head length, its tip forming a long,
slender swelling.
Body black, without pale luminous patches; head with
many small, pale dots developing with growth behind eye
and on gill cover. Attains 26 cm. Occurs only in tropical
Atlantic to about 20 0 S.
231