Comparative Genomic and Mitochondrial Phylogenetic Relationships of
Ovulidae (Mollusca: Gastropoda) Along the Chinese Coast
Abstract
The Ovulidae family, closely related to Cypraeidae (cowries), comprises
approximately 260–280 species predominantly inhabiting tropical and
subtropical shallow marine environments. Traditional morphological
classification within Ovulidae has been challenging due to significant
variability influenced by their host organisms. In this study, we
collected 15 Ovulidae species from China’s offshore waters, including
the first regional record of Habuprionovolva aenigma (M. Azuma &
C. N. Cate, 1971). We sequenced the mitochondrial genomes of 14 species
and found that, except for H. aenigma, they exhibit typical
metazoan mitochondrial structures. Phylogenetic analyses based on
mitochondrial genome data were conducted to elucidate relationships
among Ovulidae genera. Notably, we discovered that the subfamily
Prionovolvinae exhibits a unique mitochondrial tRNA gene order. Our
results suggest that mitochondrial gene rearrangements occurred after
the divergence of the Prionovolvinae and Ovulinae subfamilies.
Additionally, we found that Ovulidae species display significantly
higher Ka/Ks ratios compared to Cypraeidae, indicating different
selective pressures possibly linked to their unique feeding habits.
Based on these findings, we propose reclassifying certain genera from
the Simniinae subfamily to the Prionovolvinae subfamily. This research
enhances the understanding of Ovulidae phylogeny and provides genomic
resources for future studies.