Diaphus lucidus

Common Name

Spotlight Lanternfish

Year Described

Goode & Bean, 1896

Identification

Dorsal Fin: 17
Anal Fin: 17-18
Pelvic Fin: 8
Pectoral Fin: 11-12
Gill Rakers: 16-19
Lateral Line: 38

Body Photophores
PVO: 2 (first at base of pectoral fin; two PVO in almost straight line with first PO)
PO: 5 (first well separated from rest; 2-3-5 in straight line; fourth elevated above level of others about at level of pectoral fin base)
VO: 5 (first, second, and third in an ascending line; third almost directly above fourth; first, fourth and fifth in straight line)
SAO: 3 (first over anus at similar level as VO5; in steep curved line; third right below LL well separated from first two almost on LL)
AOa: 7-8 (first elevated over second; last elevated slightly; rest in line)
AOp: 4-6 (almost a straight line, first before, on, or after last anal fin ray)
Prc: 4 (curving line with the fourth separated more than the other three; fourth 1.5-3 times diameter under LL)
PLO: 1 (closer to lateral line than pectoral fin, directly over second PVO)
VLO: 1 (much closer to LL than pelvic fin base)
Pol: 1 (right under LL; slightly posterior to last AOa)

Body photophores relatively small. A large triangular luminous scale adjacent to PLO is 3 times its size.

Head Photophores
Dn: present on the antero-dorsal part of orbit above nostril; very large, rounded, and anteriorly directed. Organ can get half the size of the eye and extend over the frontal ridges.
Vn: present on the anterior and antero-ventral part of the orbit; elongate and thin, running from Dn to the ventral part of the orbit, including the rear margin of the nasal organ. Mature adults with similar sized organs. A dark band of tissue surrounds the organ.
Op: 2 (first obscured behind jaw, second above it is similar in size to a body photophore).

Color

Body black with paler photophores. Naked skin pale. Dark tissue surrounds the Dn and most of the Vn.

Size

Mature adults from 80-100mm.

Habitat

Deepwater oceanic. Vertical migrator: found at 425-750m by day and 40-550m at night.

Range Map

 Range Map

Range

Tropical Atlantic: scattered records from off Florida and the Keys, the Lesser Antilles, and off NE South America but likely widespread in the Gulf of Mexico and Caribbean. Also across the equatorial Atlantic.

References

Hartel, K.E. and J.E. Craddock. 2003. Myctophiformes. pp. 942-951. In: FAO Species Identification Guide to Fishes of the Western Atlantic. (ed. Carpenter, K.), pp. 1308–1369. UN FAO Publishers, Rome.

Nafpaktitis, B.G. 1968. Taxonomy and distribution of the lanternfishes, genera Lobianchia and Diaphus, in the North Atlantic. Dana Report No. 73: 1-131, Pls. 1-2.

Nafpaktitis, B.G. 1977. Family Myctophidae. In: Fishes of the western North Atlantic. Sears Foundation for Marine Research. Part 7, No. 1: 13-258.

Other Notes

The high number of AOa photophores is diagnostic of this species.