Exploring the morphological variation of the hybrids between Crocodylus acutus and Crocodylus moreletii in the Mexican Caribbean through a 2D geometrics morphometric approach

SECULI PEREYRA, EMANUEL; PASCHETTA, CAROLINA

Puerto Madryn

Jornada; II Encuentro Patagónico de Becaries y X Jornada de Becaries CENPAT; 2023

Hybridization between species has been a controversial topic and it has attracted theattention of different areas in evolutionary biology. In México, this process is present intwo crocodile species, Crocodylus acutus and Crocodylus moreletii. They occursympatrically in the wild in the Peninsula of Yucatán, due to the accidental introductionof C. moreletii in the Oaxaca coast. The genetic and morphological diversity of the C.acutus population in the Mexican Caribbean are in trouble due the economic exploitationof the species through time, illegal trafficking, drowning in fishing nets, and geneticintrogression of C. moreletii. Although some research exists about their genetics, therewas no research done on hybrid morphology until now. In this sense, the goal of this studywas to describe the morphological differences of the hybrids in relation to their parentspecies using geometrics morphometrics technique and determinate which factors (size,species and location) influence the shape of skull with randomized lineal models. Themain morphological differences between species and hybrids were found in theviscerocranium region, being the left side of the hybrid skulls more similar to C. acutusand the right side more similar to C. moreletii. However, considering the skull as a whole,the hybrids were more similar to C. moreletii. This adds to previous results and providesevidence that C. acutus is losing both genetic and morphological diversity in Mexico.This result highlight the relevance of the insular population of C. acutus, which representsa genetic and morphological reservoir for the species.