| Moderately slender; gut length moderate, slightly sigmoid; eye elliptical with lunate mass of choroid tissue; Br2 photophores and caudal luminous glands form in late larvae; ventral finfold pigment present throughout larval period; lacks midlateral pigment series (present in T. nigrescens); fewer postanal ventral midline melanophores than in Stenobrachius leucopsarus (11-14 vs. 19-22); S. leucopsarus and Diaphus theta lack ventral finfold pigment.
Pigmentation:
Preflexion: at 2.0-3.5 mm, 11-14 in postanal ventral midline series, ventrolateral pair on gut just posterior to pectoral fin base, 1 or 2 pairs on midlateral gut, pair on terminal gut section, and some along ventral margin of finfold; 1 just posterior to adipose fin locus in most larvae >3.7 mm; anterior pair on gut coalesces to 1 on ventral midline in most larvae >4.0 mm; embedded above gas bladder by 4.3 mm; postanal series reduced to 1 or 2 by end of stage.
Flexion: at lower jaw symphysis; lateral gut pair(s) coalesced and embedded above gut.
Postflexion: by 9.0 mm, at angle of lower jaw, delicate series at base of inferior procurrent caudal rays, and 1 at anal fin insertion; by 10.5 mm, embedded anterior to pectoral fin base.
Sequence of fin development: caudal, anal, dorsal, pectorals, pelvics. |