| Pigmented branchiostegal membranes; dorsal pigment on head primarily medial; compared with A. retrosella, eyes tend to be smaller and more oval and caudal peduncle slightly longer.
Pigmentation:
Preflexion: Internally on posterior margin of midbrain after 3 mm; 1-2 on ventral margin of isthmus; on branchiostegal membrane, beginning as posteroventral patch and spreading to cover membrane; dorsally on gas bladder and hindgut; 1-few on ventrum of gut.
Flexion: Over forebrain by 4.1 mm, spreading posteriorly over midbrain; increasing internally around posterior margin of midbrain; spreading down anterior margin of gut; 0-1 ventrally on gut.
Postflexion: Increasing over fore- and midbrain, primarily along longitudinal midline; internally ventrolaterally on hindbrain at 4.5 mm, surrounding it by 5.2 mm; spreading upward from branchiostegal membrane onto gill cover.
Sequence of fin development: principal caudal fin rays, second dorsal fin and anal fin, pectoral fin, first dorsal fin, procurrent caudal fin rays, pelvic fin. |