Dorsal coloration consists of green, yellow, and black marbling.

Another yellow line touches the lip and extends backward to the tympanum.

A vague transverse band is located at the shoulders and another, more distinct one half-way along the dorsum.

[6] Eleutherodactylus karlschmidti is an aquatic species that occurs in mountain streams at elevations of 45–630 m (148–2,067 ft) above sea level.

[1] This species was once abundant in eastern Puerto Rico as well as in the western mountains.

The likely reason is a combination of the fungal disease chytridiomycosis and climate change.