First mitochondrial genomes in the Effusa clade (Gastropoda, Ampullariidae): unveiling new insights from Neotropical endemic Pomacea spp.

Abstract Background Pomacea is the most diverse genus of the freshwater snail family Ampullariidae, which have been proposed as model organisms in biogeography, speciation and invasive biology. While substantial effort has been put into the mitochondrial genomes of Pomacea clades associated with invasive species ( P. canaliculata and P. bridgesii groups), comparatively little is known about the mitogenomic organization and structure within the Effusa clade. Results This study provides the first complete and annotated mitochondrial genomes of the Effusa clade, based on Pomacea nobilis (Reeve, 1856) and a putative undescribed Pomacea lineage (hereafter Pomacea sp.). The mitochondrial genome of P. nobilis (16,279 − 16,471 bp) and Pomacea sp. (16,355 bp) are among the largest recorded for Pomacea and contain the typical 37 animal genes. A comparative analysis with other Ampullariidae revealed that the Effusa clade differs from both P. canaliculata and P. bridgesii clades mainly by the higher proportion of intergenic regions, the size of many genes ( ATP8 , ATP6 , NAD6 , COIII and NAD2 ), the largest ribosomal RNAs among Pomacea and a putative large repetitive unit in the control region. Conclusion These findings highlight the distinctiveness of Effusa clade mitogenomes in comparison with the P. canaliculata and P. bridgesii groups. Further mitogenomic studies on underexplored Pomacea lineages will be important to broaden our understanding of mitochondrial genome diversity among apple snails.