Evidence for a single population expansion event across 24,000 km: the case of the deep-sea scavenging amphipod Abyssorchomene distinctus
Dupont, D.W.E.; Patel, T.; Kochzius, M.; Schön, I. (2024). Evidence for a single population expansion event across 24,000 km: the case of the deep-sea scavenging amphipod Abyssorchomene distinctus. Hydrobiologia 851: 2309-2327. https://dx.doi.org/10.1007/s10750-023-05447-5 In: Hydrobiologia. Springer: The Hague. ISSN 0018-8158; e-ISSN 1573-5117, more | |
Keywords | Abyssorchomene distinctus (Birstein & M. Vinogradov, 1960) [WoRMS] Marine/Coastal | Author keywords | Cryptic diversity; Deep-sea mining; Population genetic structure; Phylogeography; Population range expansion |
Abstract | Anthropogenic activities such as mining pose a putative threat to deep-sea ecosystems and baseline studies of key indicator species are required to assess future loss of biodiversity. We examined population genetic structure, connectivity, cryptic diversity and phylogeography of the deep-sea scavenging amphipod, Abyssorchomene distinctus, using DNA sequence data (mitochondrial COI and nuclear 28S genes) from 373 specimens collected from six abyssal basins. We observed a striking absence of cryptic diversity, suggesting a single, widely distributed species in the Pacific and Indian Ocean. A single event of population expansion across distances up to 24,000 km is further supported by a main ancestral haplotype in the star-like shaped COI haplotype network, a skewed nucleotide mismatch distribution and deviations from evolutionary neutrality tests. In the Pacific, A. distinctus showed weak genetic population structure and low differentiation between the basins of the Clarion-Clipperton Zone and the DISCOL Experimental Area, suggesting a possible higher chance of recovery from deep-sea mining impacts. However, since our data indicate a single recent historic population expansion event, A. distinctus populations will likely be affected to unknown extents, as the exact drivers shaping distribution and dispersion of A. distinctus are still unclear. |
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