Santamaria Carlos A, Bork Annabelle, Larson Alexandra J, Link Daniel J
Department of Biology, University of Tampa, Tampa, FL, United States of America.
Papahānaumokuākea Marine National Monument, US Fish and Wildlife Service, Honolulu, Hawai' i, United States of America.
PeerJ. 2025 May 22;13:e19373. doi: 10.7717/peerj.19373. eCollection 2025.
Isopods in the genus have been shown to harbor deeply divergent genetic lineages that have, in some instances, been recognized as cryptic species. For instance, the use of molecular taxonomic approaches to characterize coastal from the Hawaiian Islands led to the redescription of , the sole endemic coastal species previously recognized in the region, and to the description of seven new species endemic to the region. These species appear to be highly restricted to rift zones within single islands, single islands, or previously connected islands, suggesting these species evolved in allopatry. These findings, coupled with the poor dispersal capabilities exhibited by isopods and the geology of the Hawaiian Islands, suggest that additional cryptic species may exist in highly isolated populations yet to be studied. Studies to date have characterized from throughout the younger Hawaiian Islands (, Kaua' i, O' ahu, Moloka' i, Maui, Lanai, and Hawai' i); however, no endemic populations from the older islands and more remote islands that form part of the Papahānaumokuākea Marine National Monument (PMNM) have been studied. This region represents the largest marine conservation area in the USA, and includes at least three islands where have been previously reported from. Herein, we apply molecular taxonomic approaches to characterize specimens from Nihoa, a remote island in the PMNM. Results show that from Nihoa form a highly divergent that is reciprocally monophyletic lineage with other Hawaiian species. This lineage, described as sp. nov., adds to the known biodiversity of the PMNM and highlights the importance of continued exploration and conservation of this remote and highly biodiverse region.
该属等足类动物已被证明拥有深度分化的遗传谱系，在某些情况下，这些谱系已被认定为隐存种。例如，利用分子分类学方法对夏威夷群岛的沿海等足类动物进行特征描述，导致对该地区先前认定的唯一特有沿海物种进行了重新描述，并描述了该地区特有的七个新物种。这些物种似乎高度局限于单个岛屿、单个岛屿内的裂谷带或先前相连的岛屿，这表明这些物种是在异域中进化而来的。这些发现，再加上等足类动物表现出的较差扩散能力以及夏威夷群岛的地质情况，表明在尚未研究的高度隔离种群中可能存在更多隐存种。迄今为止的研究已经对整个较年轻的夏威夷群岛（考艾岛、瓦胡岛、莫洛凯岛、毛伊岛、拉奈岛和夏威夷岛）的等足类动物进行了特征描述；然而，尚未对构成帕帕哈瑙莫夸基亚海洋国家纪念区（PMNM）一部分的较古老岛屿和更偏远岛屿上的特有等足类动物种群进行研究。该地区是美国最大的海洋保护区，包括至少三个先前已报告有等足类动物的岛屿。在此，我们应用分子分类学方法对来自PMNM中一个偏远岛屿尼霍阿岛的等足类动物标本进行特征描述。结果表明，来自尼霍阿岛的等足类动物形成了一个高度分化的、与其他夏威夷等足类物种相互单系的谱系。这个谱系被描述为新物种，增加了PMNM已知的生物多样性，并突出了对这个偏远且生物多样性极高的地区持续进行探索和保护的重要性。
