Meng Yiping, Lv Liyuan, Lin Zhihua, Zhang Demin, Dong Yinghui
School of Marine Sciences, Ningbo University, Ningbo 315010, China Ningbo University Ningbo China.
College of Advanced Agricultural Sciences, Zhejiang Wanli University, Ningbo 315101, China Zhejiang Wanli University Ningbo China.
Zookeys. 2025 Mar 19;1232:249-266. doi: 10.3897/zookeys.1232.139844. eCollection 2025.
Pharidae is one of the most ecologically and commercially significant families of marine Bivalvia; however, the taxonomy and phylogeny of Pharidae has been ongoing for quite some time and remains a contentious issue. Here, to resolve some problematical relationships among this family, the complete mitochondrial genomes (mitogenomes) of (17,159 bp) and (15,957 bp) were assembled, and a comparative mitochondrial genomic analysis was conducted. Both mitogenomes contain 12 protein-coding genes, 22 transfer RNA genes, and two ribosomal RNA genes. Among the published Pharidae mitogenomes, exhibited the smallest genome size but the highest AT content. The results of the phylogenetic trees confirmed the monophyly of the family Solenoidea, and indicated that and ( and ) were closely related in the family Pharidae. From the CREx analysis, we found that transposition and tandem duplication random losses (TDRLs) might have occurred between Pharidae and Solenidae. Moreover, positive selection was detected in nad5 of the foreground , and divergent evolution occurred at site 144 in the freshwater and marine lineages. Overall, our findings provide new molecular data on the phylogenetic and evolutionary relationships of Pharidae, and contribute to unraveling the salinity adaptations of Pharidae.
贻贝科是海洋双壳贝类中在生态和商业方面最重要的科之一；然而，贻贝科的分类学和系统发育学研究已经进行了相当长的时间，仍然是一个有争议的问题。在此，为了解决该科中一些有问题的亲缘关系，我们组装了（17,159 bp）和（15,957 bp）的完整线粒体基因组（线粒体基因组），并进行了比较线粒体基因组分析。两个线粒体基因组都包含12个蛋白质编码基因、22个转运RNA基因和两个核糖体RNA基因。在已发表的贻贝科线粒体基因组中，表现出最小的基因组大小但最高的AT含量。系统发育树的结果证实了竹蛏超科的单系性，并表明在贻贝科中与（和）关系密切。从CREx分析中，我们发现转座和串联重复随机丢失（TDRLs）可能在贻贝科和竹蛏科之间发生。此外，在前景的nad5中检测到正选择，并且在淡水和海洋谱系的第144位点发生了趋异进化。总体而言，我们的研究结果提供了关于贻贝科系统发育和进化关系的新分子数据，并有助于揭示贻贝科的盐度适应性。
