Diaphus termophilus

Common Name

Taaning's Lanternfish

Year Described

Tåning, 1928


Dorsal Fin: 13-14
Anal Fin: 15
Pelvic Fin: 8
Pectoral Fin: 11-12
Gill Rakers: 23-26
Lateral Line: 35-36

Body Photophores
PVO: 2 (first at base of pectoral fin; first midway between PO1 and PVO2)
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 straight line; fourth posterior to vertical from third; first, fourth and fifth in straight line)
SAO: 3 (first over anus at about same level as VO5; in steep curved line; third 2-2.5 times its diameter below LL)
AOa: 5-6 (first elevated over second; last elevated slightly; rest in line)
AOp: 4-5 (almost a straight line, first behind last ray of anal fin)
Prc: 4 (curving line with the fourth separated more than the other three; fourth 2-2.5 times diameter under LL)
PLO: 1 (closer to pectoral fin than lateral line, directly over second PVO)
VLO: 1 (slightly closer to LL than pelvic fin)
Pol: 1 (at same distance from LL as SAO3; slightly posterior to last AOa)

A large triangular luminous scale adjacent to PLO is 2-3 times its size.

Head Photophores
Dn: present on the antero-dorsal part of orbit above nostril; small, oval, and anteriorly directed.
Vn: present on the ventral part of the orbit. Organ oval and under center of eye. Mature males with a much larger Vn than similar sized females. A thin band of dark tissue connects Dn and Vn, and 2-3 tiny light organs are embedded in this tissue.
Op: 2 (first tiny behind jaw, second above it is similar in size to a body photophore)


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


Mature adults from 56-75mm.


Deep oceanic; rarely shallower than 100m at any time of day. Vertical migrator: found at 325-850m by day and 40-225 at night.

Range Map

 Range Map


Tropical Atlantic: most records from S. Florida, the SE Gulf of Mexico, the Caribbean Sea, and the adjacent Atlantic around the Caribbean islands. Vagrants into the Central Atlantic and the Gulf Stream.


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.