Identification.—1 followed Moser and Ahlstrom (1972, 1974) in 
their concept of the genus. I made no attempt to identify the 
specimens to species. 
Lampanyctus complex (45 occurrences, 82 larvae).—Larvae of 
Lampanyctus were ranked fifth in abundance among the genera, 
and three types were identified to species. Ahlstrom (1971, 1972) 
found larvae of this genus to be the second most abundant myc- 
tophid; Houde et al. (footnote 4) did not find it very abundant in 
the eastern Gulf of Mexico; Nellen (1973) found it to be the third 
most abundant in the western Indian Ocean. 
Identification.—I followed Moser and Ahlstrom (1974). Because 
of the presence of seven species in the Gulf or Caribbean, I was 
not able to identify all of the material to species. 
Lampanyctus spp. (12 occurrences, 18 larvae, and 2 
juveniles).—Only these few larvae were not specifically identified. 
A single juvenile specimen was L. alatus, and this was the most 
abundant species of Lampanyctus in the eastern Gulf of Mexico 
(Houde et al. footnote 4). 
Lampanyctus cuprarius (7 occurrences, 8 larvae).—This species 
occurred rarely. Nafpaktitis et al. (1977) indicated that the center 
of abundance of this species is the subtropics, although it is found 
in significant numbers in the Caribbean area. Houde et al. (foot- 
note 4) collected 16 specimens in the eastern Gulf of Mexico. 
Identification.—I followed an unpublished account of Ahlstrom® 
for this species, which has a long snout with a distinct streak of 
pigment, pigment on the tip of both jaws, behind the eye, around 
the nares, and between the forebrain and midbrain, but it lacks 
trunk pigment. 
Lampanyctus nobilis (35 occurrences, 55 larvae).—This was the 
most abundant species of Lampanyctus having a wide distribution 
throughout the area in both seasons. It is also the third ranked 
myctophid species of those identified to species. The adults are 
also widely distributed in the area (Nafpaktitis et al. 1977). Houde 
et al. (footnote 4) did not report this species, but my later ex- 
amination of the unidentified specimens revealed it to be the se- 
cond most abundant species after L. a/atus in his eastern Gulf col- 
lection. 
Identification.—This species is often mistaken for tuna larvae by 
inexperienced identifiers because of its similar head and body pro- 
file. However, the head is laterally compressed with complex 
pigmentation on the gular membrane, tip of lower jaw, forebrain, 
hindbrain, and gut. 
Myctophum complex (75 occurrences, 190 larvae).—Larvae of 
this genus were widely distributed and ranked third in abundance. 
All but five larvae were identified to species. Larvae of all species 
known as adults were taken from the area (Nafpaktitis et al. 
1977). Ahistrom (1971, 1972) obtained two species (M. nitidulum 
and M. asperum) in the tropical Pacific common to those in this 
area. 
°E. H. Ahlstrom, late of the Southwest Fisheries Center, La Jolla Laboratory, 
National Marine Fisheries Service, NOAA, La Jolla, CA 92037. Unpublished il- 
lustrations and identified specimens in his collection. 
14 
Myctophum affine (9 occurrences, 13 larvae).—This species oc- 
curred rarely, but more abundantly during the summer. Adults of 
this species are tropical and show unusual scarcities in some areas, 
but are abundant in the Caribbean and Gulf (Nafpaktitis et al. 
1977). No specimens of this species were taken by Houde et al. 
(footnote 4) in the Gulf of Mexico. 
Identification.—Five species occur in this area and of those all but 
M. affine have been described. I assume this undescribed larval 
type to be M. affine. It is nearly identical to M. nitidulum in body 
and eye shape but differs in pigmentation. It has a row of 
melanophores along the posterior ramus of the lower jaw, a few 
melanophores behind the eye, one pigment spot on each side of 
the midbrain, and one behind the midbrain. Pigmentation on the 
trunk consists of melanophores at the pectoral symphysis, above 
the pectoral fin base, a few ventrally posterior to the pectoral sym- 
physis, and on the anal papilla. Distinct pigment blotches occur 
beneath the posterior end of the dorsal fin, below the adipose fin, 
and above the anal fin. 
Myctophum asperum (5 occurrences, 5 larvae).—This species 
occurred rarely in the area. Adults are tropical and found com- 
monly in this area (Nafpaktitis et al. 1977). Houde et al. (footnote 
4) captured one specimen in the eastern Gulf of Mexico; Ahlstrom 
(1972) found this species offshore in an equatorial tongue in the 
eastern tropical Pacific. 
Identification.—Moser and Ahlstrom (1974). 
Myctophum nitidulum (19 occurrences, 35 larvae).—This 
species was commonly taken throughout the area and was found 
to be widespread and abundant by Nafpaktitis et al. (1977). It was 
the most abundant Myctophum species in the eastern Gulf of 
Mexico (Houde et al. footnote 4) and was one of the commonest 
Myctophum found in the eastern tropical Pacific (Ahlstrom 1971, 
1972) and western Indian Ocean (Nellen 1973). 
Identification.—Moser and Ahlstrom (1970, 1974). 
Myctophum obtusirostre (33 occurrences, 51 larvae).—This 
species was more abundant during the winter than the summer 
and is common throughout the area. Adults exhibit a tropical 
distribution (Nafpakitis et al. 1977). In the eastern Gulf of Mexico 
only two specimens were captured (Houde et al. footnote 4). 
Myctophum selenops (47 occurrences, 81 larvae).—This was 
the second most abundant myctophid taxon identified to species. 
It occurred in both seasons but was more abundant during the 
summer (Table 10, Fig. 6). Nafpaktitis et al. (1977) considered this 
species to be uncommon with a tropical-subtropical distribution 
pattern. In contrast, it was the most abundant Myctophum in my 
material. Houde et al. (footnote 4) found this to be the second 
most abundant Myctophum in the eastern Gulf of Mexico. 
Identification.—Moser and Ahlstrom (1974). 
Bolinichthys spp. (19 occurrences, 24 larvae).—Three species of 
Bolinichthys have been recorded as adults in this area and two 
others occur in adjacent areas. Larvae were uncommon but 
widespread in this area (Table 10). One positively identified 
specimen of B. supralateralis was collected in the Gulf of Mexico. 
Adults of this species were common to the area (Nafpaktitis et al. 
1977). Larvae of this genus were not taken in the eastern tropical 
