Melanostomiidae
(Melanostomiatidae in Clofnam)
by R. H. Gibbs, Jr.
Small to moderate deepwater fishes (to almost 40 cm, but mostly 15-30 cm); body fairly or very elongate, scaleless, black (sometimes iridescent green, blue or bronze). Snout short, eye near front of head; mouth large, with small sharp teeth, often fang-like; barbel present under chin, less than head length to very long (but long barbels frequently broken); floor of mouth present, membrane connecting lower jaw halves to isthmus. Dorsal and anal fins opposite and at hind part of body, ending near base of tail; no dorsal adipose fin (except in Chirostomias). Two rows of prominent photophores on each side along lower part of body, the upper or lateral row (OA) and below it the ventral row (IC); light organs variously present before, below or behind eye or scattered on body.
Fairly common in deep oceanic waters, especially in the tropics and subtropics; mesopelagic, usually living deeper than 500 m during the day; some individuals migrating to near-surface waters at night. Feeding habits poorly known; most species feeding on relatively large prey, mostly or entirely midwater fishes, but a few consume mostly crustaceans.
Genera 15; in Clofnam area 11.
Recent revisions: Regan and Trewavas (1930), Morrow and Gibbs (1964).