Diagnosis: broad black band on outer edge of anal fin (especially in the much-smaller females); anterior dorsal fin rays extremely short, sometimes barely visible, more elongated in posterior portion; caudal fin in males somewhat lanceolate, although upper parts may possess elongated rays, giving it a lobe-like appearance; caudal fin more rounded in females; dorsal, anal and pelvic fin rays can be extremely elongated in males (Ref. 52307).

Coloration: body bluish-gray, sometimes turquoise in the most anterior parts; snout, throat and breast slightly orange in some specimens; males with dark margins on body scales and well-developed rows of maculae on dorsal, anal and most of the caudal fin (save for the thin white margin on the upper edge); ripe females with red to violet belly that becomes extremely swollen immediately prior to spawning; large, white genital papilla always visible (Ref. 52307).