Morphological and Mitochondrial Evidence Supporting New Records of Leatherleaf Slugs (Gastropoda: Veronicellidae) in Mexico

Based on external morphology, genital anatomy, and a fragment of the mitochondrial 16S rRNA gene, we identified two veronicellid slug species from Chiapas, Mexico: Simrothula prismatica (Simroth, 1914) and Diplosolenodes occidentalis (Guilding, 1824), both newly recorded in the country. The available molecular data supported the identification of D. occidentalis, a species with a documented invasive history in various tropical and subtropical regions worldwide. Although no sequences were available for S. prismatica, the genital anatomy of the specimens was consistent with the original species description. These findings underscore the need for more comprehensive molecular reference databases and continued biomonitoring of veronicellid slugs in Mexico, given their potential ecological and agricultural impacts. These new records increase the known diversity of the group to five species in the country.