Phylogenetic position of Oncomelania lorelindoensis and taxonomic reassessment of former Oncomelania minima and selected snails (Pomatiopsidae)

Abstract The genus Oncomelania comprises important intermediate hosts of Schistosoma japonicum across East, Southeast Asia, and Africa. However, evolutionary relationships and taxonomic boundaries among several lineages remain unresolved. This study investigated mitochondrial sequence similarities and phylogenetic relationships involving COI and complete mitochondrial genomes. NCBI BLAST was used to compare sequence identities and generate relationship trees, while PhyML provided complementary maximum-likelihood analyses. The results support Oncomelania lorelindoensis as a basal lineage within the genus and indicate that O. minima represent a distinct evolutionary lineage outside Oncomelania . The distinct evolutionary position of O. minima supports that it represents a separate family, called here as Mewengkangiidae. Sequence identity analyses also support reassignment of O. hupensis chiui as O. nosophora , based on approximately 95% identity with O. nosophora . Similarly, O. hupensis , including O. hupensis hupensis , is reassigned as O. nosophora nelwanii , based on approximately 94% sequence identity. These eliminate the O. hupensis complex as a taxonomic grouping within the revised classification. Overall, the findings provide a revised interpretation of Oncomelania evolution and highlight the importance of comparative mitochondrial sequence analyses for taxonomic investigations.