Diaphus luetkeni

Common Name

Luetken's Lanternfish

Year Described

Brauer, 1904

Identification

Dorsal Fin: 15-17
Anal Fin: 14-16
Pelvic Fin: 8
Pectoral Fin: 11
Gill Rakers: 20-23
Lateral Line: 35-36

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 same level as VO5; in steep curved line; third right below LL)
AOa: 5-7 (first elevated over second; last elevated slightly; rest in line)
AOp: 4-6 (almost a straight line, first over last ray of anal fin)
Prc: 4 (curving line with the fourth separated more than the other three; fourth 2 times diameter under LL)
PLO: 1 (much closer to pectoral fin than lateral line, directly over second PVO)
VLO: 1 (closer to pelvic fin base than LL)
Pol: 1 (right under LL; slightly posterior to last AOa)

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; small, rounded and anteriorly directed.
Vn: present on the antero-ventral part of the orbit; very elongate; increases in size with age. In mature females it does not contact the nostril but runs under the ventral margin of the eye to around the posterior margin of the pupil. In mature males, the organ is thickened anteriorly, touches the nasal organ, and runs under the ventral margin of eye. Folds are present in the dark tissue surrounding the Vn, which have small light organs embedded in them.
Op: 2 (first tiny 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. Fins speckled.

Size

Mature adults around 60mm.

Habitat

Oceanic. Vertical migrator: found at 375-750 by day and 40-325 at night.

Range Map

 Range Map

Range

Tropical Atlantic: Florida, the Gulf of Mexico, the Caribbean, to the equatorial Atlantic off NE Brazil. Vagrants carried north in the Gulf Stream.

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.