Fins - D1 - IV, none filamentous; D2 - 15(14-16); pectoral - 20(21-20); anal - 13(13-14)

Head - Maxilla extending more than pupil diameter beyond posterior of eye; interorbital very narrow 2.8-6.0 in orbital diameter.

Papillae -

Color - Background color translucent in life, whitish in alcohol. Epidermal pigments consisting of pupil-sized white guanine blotches overlaid by rather evenly scattered individual brown or black melanophores. Effective pattern evenly speckled or specific melanophores expanded to create black blotches along dorsal midline or crosshatching on upper half of body. Belly white. Melanophores of lower half of head enlarged; on females a few melanophores on tip of chin, on males covering entire throat and ismus. Resultant color pattern of fish highly cryptic against sand substrate of habitat.

Distal three-quarters of first dorsal spine black, base transparent; tip or most of fourth spine also black; remainder of fin transparent. Ray's of second dorsal fin usually with melanophores proximally, a clear area and remaining 4/5 of ray blackened; interradial membranes transparent. Anal fin transparent proximally, distal 2/3, inculding rays and interradial membranes disky (females) or jet-black (males); extreme tips of anal rays usually white creating a thin (males) or wider (females) white distal margin to anal fin. Caudal fin of females transparent with black speckling especially concentrated on dorsal margin, forming a dark vertical bar on caudal base and a general duskiness on lower third of fin. In males caudal pigmentation is intenser, forming a continuous thin black upper margin and a black lower third containing the black marking of anal fin. Pectoral fins speckled with melanophores; pelvics in females usually transparent, dusky in males. (Bussing 1983)

Distribution - East Pacific; Costa Rica

Habitat - Found in burrows in the upper half of the littoral zone of sandy beaches.

Notes -