Genus: Rivulus, Rivulines

RIVULUS

RIVULINES

Body elongate, cylindrical; head flattened; sensory system on top of head with grooves and exposed pads rather than pores; covering of eye partly continuous with skin of head; mouth slightly upturned, at front, short, not reaching under eye, top jaw extendible; teeth small, weak, with a single point; front nostril may be in a forward projecting tube, rear nostril a small slit before and above eye; fins without spines, although 1st ray may be unbranched; dorsal fin at rear of body, its origin over base of last few anal rays; dorsal fin 8-11, anal fin 10-17; pelvics on abdomen, at rear; pectorals rounded, on mid-side; tail fin rounded; body with smooth scales; lateral line reduced to sensory pits along side of body; fertilization internal, with eggs then being laid.

A freshwater to brackishwater genus with ~65 species, 3 brackishwater members in our area, 1 endemic and 1 W Atlantic.