Redescription and diagnoses of the genera Profundulus and Tlaloc (Cyprinodontiformes: Profundulidae), Mesoamerican endemic fishes

Abstract

Until recently, the genus Profundulus was classified in two subgenera, Profundulus and Tlaloc, the sole members of the family Profundulidae. Newly discovered molecular data have been used to justify the elevation of these subgenera to genera. Yet morphological analyses to diagnose the two genera are lacking. The aim of this study is to provide a generic diagnosis and a taxonomic key to the species within the family Profundulidae based on morphology. The genus Tlaloc is diagnosed on the basis of five unique characters, among which are the prominent and oval-shaped mesethmoid, exceeding the posterior margins of the vomer; the anterior portion of the parasphenoid making contact with the mesethmoid and extend beyond the center of the mesethmoid; and a reduced autopterotic fossa. Profundulus is diagnosed here based on the following characters: the mesethmoid is small, crescent-shaped, and does not extend beyond the margins of the vomer; the anterior portion of the parasphenoid just contacting the mesethmoid and not extending beyond the center of the mesethmoid; a large autopterotic fossa. For each genus, description and distribution ranges are provided as well as a key for identification of the species.