Common Name
Madeira Whalefish
Year Described
Maul, 1969
Identification
Dorsal Fin: 17-19
Anal Fin: 18
Pectoral Fin: 22-23
Lateral Line Pores: 20
Gill Arches: 3.5
Vertebrae: 49 (total)
Genus diagnosis after Paxton (1989) for females:
Upper jaw length 28-33% SL. Predorsal Length 75-78% SL. Body rather elongated with a huge mouth (third of body length). Snout rounded. Eye tiny. Nasal organ small. Jaws slightly concave. Free gill arches number three with a short slit behind the fourth. Gill tooth plates contiguous. Lateral line conspicuous with large round pores inside a channel with raised rim. No vertical rows of papillae on lateral line. Small dermal flaps present on lateral pores. 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 several irregular, diagonal rows. Vomerine tooth patch round or oval. Dorsal and anal fins located far back on body, with bases slightly elevated. Cavernous tissue located around the anus, anal fin base, and around anterior dorsal base, but not on caudal peduncle. Caudal fin with less than 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.
Males and juveniles unknown.
Color
Preserved specimens uniformly blackish-brown with darker pigment on the gut and pores. Inside of mouth whitish.
Size
Maximum size to 150mm SL. Common under 80mm SL.
Habitat
Inhabits mesopelagic and bathypelagic depths from 500-1500m. Smaller fish in shallower depths.
Range
Known from scattered localities in the Atlantic and Pacific: in our region recorded from the Gulf of Mexico in McEachran & Fechhelm (1998) and Paxton et al. (2016). Known from 11 specimens.
References
Maul, G.E. 1969. On the genus Cetomimus (Cetomimidae) with the description of a new species. Bocagiana. Museu Municipal do Funchal (História Natural) No. 18: 1-12.
McEachran, J.D. & J. D. Fechhelm. 1998. Fishes of the Gulf of Mexico. Volume 1: Myxiniformes to Gasterosteiformes. Univ. of Texas Press, Austin. 1-1112.
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.
Paxton, J.R., T. Trnski & G.D. Johnson. 2016. Cetomimidae (Pp. 2173-2181). In: Carpenter & De Angelis (eds.). 2016. The living marine resources of the Eastern Central Atlantic. vol. 3.
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
Can be distinguished by the combination of high pectoral count, slit behind arches, and dorsal cavernous tissue from all other Cetomimus except Cetomimus compunctus. Mouth size, fin base length, and distribution of cavernous tissue differentiates this species from C. compunctus (Maul, 1969; Paxton et al., 2016).