AUTHOR=Wang Fenglin , Liu Qi , Qu Yinquan , Gao Tianxiang , Guo Xingle , Zhang Xiumei 

TITLE=Whole-genome survey reveals the genomic characteristics and phylogeny of three species within the family Echeneidae

JOURNAL=Frontiers in Marine Science

VOLUME=Volume 12 - 2025

YEAR=2025

URL=https://www.frontiersin.org/journals/marine-science/articles/10.3389/fmars.2025.1586527

DOI=10.3389/fmars.2025.1586527

ISSN=2296-7745

ABSTRACT=The family Echeneidae, which belongs to the order Carangiformes, is a group of marine fish recognized for their distinctive hitchhiking behavior. In this study, high-throughput sequencing technology was utilized to investigate the genomic characteristics of three species within the family Echeneidae. The results indicated that the genome sizes of Remora remora, Remora albescens, and Echeneis naucrates were 677.93 Mb, 574.19 Mb, and 572.04 Mb, respectively, and they exhibited similar genomic features. The GC content of these species ranged from 40.37% to 41.50%, the repeat sequence proportion varied between 27.98% and 39.53%, and the heterozygosity rate extended from 0.43% to 0.65%. A total of 527,027, 440,593, and 458,014 simple sequence repeats (SSRs) were identified in the genomes of R. remora, R. albescens, and E. naucrates, with mononucleotide repeats being the predominant type. The mitochondrial genomes of the three species were successfully assembled based on the genomic data. The phylogenetic tree constructed from single-copy homologous genes demonstrated that R. remora and R. albescens clustered within the genus Remora, while E. naucrates formed a lineage in the genus Echeneis. The results of the PSMC analysis revealed that these three species experienced rapid population expansion before the Last Interglacial Period, followed by a decline in their populations after reaching their peak during the Last Glacial Period. Notably, R. albescens exhibited significant bimodal population dynamics during both the Last Glacial and Glacial Maximum Periods. Overall, this study provides valuable genomic data for the research of Echeneidae species and establishes a crucial foundation for further exploration of their evolutionary history and ecological adaptations.