genus Alepisaurus Lowe, 1833

Large elongate slender scaleless oceanic fishes with sharp teeth and a long dorsal fin that resembles a sail and a large mouth that is equipped with formidable fanglike teeth. The fish grow to a large size, attaining a maximum length of about 1.8 m. Voracious and carnivorous.

Alepisaurus possess a long and very high dorsal fin, soft-rayed from end to end, with the presence of an adipose fin behind it. The dorsal fin has 41 to 44 rays, and occupies the greater length of the back, is rounded in outline, about twice as high as the fish is deep, and can be depressed in a groove along the back. The body is slender, laterally flattened, deepest at the gill covers, and tapers back to a slender caudal peduncle. The mouth is wide, gaping to the back of the eye, and each jaw has two or three large fangs, besides smaller teeth. The adipose fin recalls that of the smelt in form and location. The caudal fin is very deeply forked. Its upper lobe is prolonged as a long filament, and although most of the specimens seem to lose this when captured. The anal fin originates under the last dorsal ray, and is deeply concave in outline. The ventral fins, are about halfway between the anal and the tip of the snout, while the pectoral fins are considerably longer than the body is deep and are situated very low down on the sides. There are no scales and the fins are exceedingly fragile.

2 species. In Mediterranean 1.