Diaphus taaningi

Common Name

Slopewater Lanternfish

Year Described

Norman, 1930


Dorsal Fin: 14
Anal Fin: 14-15
Pelvic Fin: 8
Pectoral Fin: 11
Gill Rakers: 19-23
Lateral Line: 35-36

Body Photophores
PVO: 2 (first at base of pectoral fin; two PVO in nearly straight line with first PO)
PO: 5 (first well separated from rest; fourth elevated above third forms triangle with fifth)
VO: 5 (first, fourth, and fifth in straight line along belly; second and third in straight ascending line from first)
SAO: 3 (in straight line, almost equidistant from each other or third slightly more)
AOa: 5-6 (first elevated slightly anterior to vertical from second, rest in line with last slightly elevated)
AOp: 4-6 (almost a straight line, first above or behind last ray of anal fin)
Prc: 4 (curving line with all about equidistant from each other, last well below lateral line)
PLO: 1 (closer to pectoral fin than lateral line, slightly posterior to vertical from second PVO)
VLO: 1 (about midway between pelvic fin base and lateral line)
Pol: 1 (about 1-2 photophore diameters below lateral line; between last AOa and first AOp)

A rounded luminous scale adjacent to PLO is 4 times its size.

Head Photophores
Dn: present on the antero-dorsal part of orbit behind nostril; both sexes with rounded Dn about half the size of the nasal organ.
Vn: present on the antero-ventral part of the orbit; oblong and elongate, about 4 times the size of Dn. Males with slight enlargement.
Op: 2 (first tiny behind jaw, second above it slightly larger than a body photophore)


Body black with paler photophores. Naked skin pale. Fins pale, often with speckles on the dorsal and caudal fins. Dark tissue surrounds the Dn and most of the Vn.


Mature adults from 50-70mm.


Continental waters near landmasses. Vertical migrator: found at 325-475m by day and moves toward the surface at night.

Range Map

 Range Map


Scattered records from Canada to Cape Hatteras, the Gulf of Mexico, and the S. Caribbean Sea and the Lesser Antilles.


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.