Ninespine stickleback Ninespine stickleback The ninespine stickleback ("Pungitius pungitius"), also called the ten-spined stickleback, is a freshwater species of fish in the family Gasterosteidae that inhabits temperate waters. It is widely but locally distributed throughout Eurasia and North America. Despite its name, the number of spines can vary from 8 to 12. The body of the ninespine stickleback tapers to a very narrow caudal peduncle and the caudal fin is fan-shaped. The body is less deep and more elongated than that of the three-spined stickleback with a thinner and longer caudal peduncle, but the best way of distinguishing these two species is
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