Notoscopelus caudispinosus anal fin and 11 to 13 in the pectoral fins. There are groups of photophores (small light organs) on the head and sides of the body. Above the caudal peduncle there is a row of eight to nine luminous scale-like segments in adult males, but male fish lack luminous organs above the eye and on the cheek. "N. caudispinosus" differs from closely related species in having fewer than 15 gill rakers. This species has a wide oceanic distribution in deep water habitats. It is found in the eastern Atlantic Ocean between the equator and about 35°N, but is absent from
Houndfish ages. The houndfish also has a more stout, cylindrical body and a shorter head than other needlefishes. They have dark blue backs and silver-white sides and are plain white ventrally. A houndfish has a distinct keel on the caudal peduncle, and the caudal fin itself is deeply forked. Juvenile houndfish possess an elevated, black lobe on the posterior of their dorsal fins. The longest recorded houndfish was , and the largest recorded weight was . In the Indian and Pacific Oceans, houndfish are found in the Red Sea and from the coast of South Africa, east to French Polynesia, and