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
Notoscopelus elongatus the anal fin 18 to 19, and in the pectoral fins, 12 to 13. There is a distinctive arrangement of photophores (light-emitting organs) on the head and body. At a length of about , males develop luminous, glandular patches on the dorsal surface of the caudal peduncle. It is very similar in morphology to "Notoscopelus kroyeri" but differs in having 23 to 25 gill rakers whereas "N. kroyeri" has 26 to 29. "N. elongatus" is endemic to the Mediterranean Sea where it is found in greatest abundance in the Western Basin and the Ligurian Sea and Tyrrhenian Sea. During the