Cetostoma regani

Common Name

Pink Flabby Whalefish

Year Described

Zugmayer, 1914


Dorsal Fin: 29-37
Anal Fin: 26-34
Pectoral Fin: 20-21
Lateral Line Pores: 15-17
Gill Arches: 4
Vertebrae: 47-53 (total)

Genus diagnosis after Paxton (1989) for females:

Body very elongated with a relatively short head when compared to body length (3-5 times in SL). Snout tapering and pointed. Body narrows considerably post-opercle and widens again at fin origins. Head narrow. Eye tiny. Nasal organ small. Jaws slightly convex to straight on upper but concave on lower. Four distinct gill arches with a small slit behind it. Lateral line conspicuous with large round pores inside a channel with raised rim. Lateral pores have moderate dermal flaps. No vertical rows of papillae on lateral line. Lateral line system continues onto head as a series of pores and sensory openings. Additional pores on lower jaw and snout. Jaw teeth tiny in irregular bands. Dorsal and anal fins located far back on body, with bases very elevated and very long bases. Cavernous tissue located around the anus. Caudal peduncle long and narrow. Caudal fin with 15-17 principle rays. Pelvic fin absent. Pectoral fin small and inserted low on body. Body flabby and scaleless except for large, diagnostic scales associated with the lateral line canals. Low fleshy ridges on ventral side of abdomen. Numerous small lappets around the base of each anal fin ray.

Males (described as megalomycterid Cetomimoides parri) similar to females in body form but more slender and with a huge nasal rosette.

Larvae (described as mirapinnid Parataeniophorus gulosus) are slender with a short tape-like extension of the caudal fin and upturned pectoral fins.


Body bright to dark red red overall with darker brown to blackish fins with red edging.


A large species compared to other genera: to 246mm SL for females.


Captured over a range of depths (500-1600m) with specimens usually larger in deeper waters. Based on frequency of capture it can be shown that this species undertakes limited diel vertical migration.


Widespread in the Atlantic but restricted to subtropical and tropical zones: from Bermuda to the Gulf of Mexico, the Caribbean Sea, and south to off Brazil. Also the Indian and Pacific Oceans.


Harry, R.R. 1952. Deep-sea fishes of the Bermuda oceanographic expeditions. Families Cetomimidae and Rondeletiidae. Zoologica, Scientific Contributions of the New York Zoological Society v. 37 (pt 1, no. 5): 55-72, Pl. 1.

Johnson, G.D., J.R. Paxton, T.T. Sutton, T.P. Satoh, T. Sado, M. Nishida, & M. Miya. 2009. Deep-sea mystery solved: astonishing larval transformations and extreme sexual dimorphism unite three fish families. Biology Letters, 5: 235–239.

Paxton, J.R. 1989. Synopsis of the whalefishes (family Cetomimidae) with descriptions of four new genera. Records of the Australian Museum v. 41: 135-206.

Tolley, S.G., J.V. Gartner, Jr. & T.M. Lancraft. 1989. Whalefishes (Beryciformes: Cetomimoidei) of the Gulf of Mexico. Bulletin of Marine Science v. 45 (no. 3): 671-677.

Other Notes

Johnson et al. (2009) discovered that all members of the families Mirapinnidae and Megalomycteridae are actual larvae and males repectively, of whalefishes. This explained the strange absence of male and larval specimens of Cetomimidae in collections, but the finding was unexpected as the morphology of the three groups was so different. The pairing of described “tapertail” larvae and “bignose” males is not fully described, but genetic data has paired Parataeniophorus gulosus and Cetomimoides parri with Cetostoma regani females. It is possible that Ataxolepis represents males of a Cetomimus/Gyrinomimus species and Mirapinna represents larval Procetichthys. Given the years of description of these males and larvae, these names may need to be given priority over the names of the female specimens more recently described.