Genus: Hiatirhaphis, Cascajal Mosquitofish, Mosquitofishes

HIATIRHAPHIS

MOSQUITOFISHES

Head and body moderately robust, moderately compressed at rear; head depressed; front nostril not tubular; covering of eye not continuous with skin of head; mouth small, at front, slightly oblique, lower jaw slightly projecting, top jaw protractile; jaw teeth consist of an outer row of large backward curved teeth, and several rows of small pointed teeth; 1 dorsal fin with short base, 7-9, at rear of body; anal fin origin distinctly before dorsal fin origin; pelvic origin well behind pectoral base, near anal fin, tips of pelvics of males not swollen; pectorals high on flank, male with 5th ray not scalloped; 3rd anal ray unbranched; anal fin modified in male to form an elongate sex organ, tip of that organ curved slightly upwards, without club-like spines at tip, without a fleshy palp, but may have fleshy side processes; tail base relatively narrow; tail fin rounded; scales smooth and relatively large; a conspicuous black blotch on the base of the anal fin or male sex organ.

A genus distributed in Costa Rica and Panama; with 2 species; mainly in freshwater but one in brackishwater.