Description: Body somewhat thick, very long and narrow with a small head and small round eye and medium-sized mouth with only a slightly protruding lower jaw. Pectoral fins short and pelvic fins separate and short. Dorsal and anal fin bases very long, caudal peduncle very short and relatively wide, 5-6 procurrent caudal fin rays (5 spindly). Lightly marked, mostly along the ventral midline: melanophores at the isthmus, just forward of the pelvic fin base and just behind the pelvic fin base diverging into a pair of short rows along the side of the abdominal gut strip. There is a row of melanophores along the base of all of the anal fin rays (paired and one per ray), becoming more disassociated from the anal fin base and more variable in number and depth at the last several rays and continuing along the ventral caudal peduncle midline ending under the first lower procurrent caudal fin ray. There are melanophores along the base of the last two dorsal fin rays (paired, off-center, and one per ray), and continuing along the dorsal caudal peduncle midline ending under the first upper procurrent caudal fin ray. There are one or two discrete large melanophores along the lateral midline of the caudal peduncle. Melanophores line the proximal third of the lower central caudal fin rays and the full length of the several lowest segmented caudal fin rays. Melanophores on the head are limited to a pair at the angles of the jaw. Internal melanophores occur around the saccule and along the dorsal surface of the swim bladder (not at the vent).
Diagnosis: The fin-ray count range of D-XII-XIII,37-38 A-35 indicates Microdesmus luscus. md5(U)
