Highly structured populations of deep-sea copepods associated with hydrothermal vents across the Southwest Pacific, despite contrasting life history traits

Coral Diaz-Recio Lorenzo (1) , Tasnim Patel (2) , Eve-Julie Arsenault-Pernet (3) , Camille Poitrimol (4, 3) , Didier Jollivet (4) , Pedro Martinez Arbizu (5) , Sabine Gollner (1)

1 Universiteit Utrecht / Utrecht University [Utrecht]
2 RBINS - Royal Belgian Institute of Natural Sciences
3 BEEP - Biologie et Ecologie des Ecosystèmes Marins Profonds
4 ADMM - Adaptation et diversité en milieu marin
5 Senckenberg am Meer

Hydrothermal vents are extreme environments, where abundant communities of copepods with contrasting life history traits co-exist along hydrothermal gradients. Here, we discuss how these traits may contribute to the observed differences in molecular diversity and population genetic structure. Samples were collected from vent locations across the globe including active ridges and back-arc basins and compared to existing deep-sea hydrothermal vent and shallow water data, covering a total of 22 vents and 3 non-vent sites. A total of 806 sequences of mtDNA from the Cox1 gene were used to reconstruct the phylogeny, haplotypic relationship and demography within vent endemic copepods (Dirivultidae, Stygiopontius spp.) and non-vent-endemic copepods (Ameiridae, Miraciidae and Laophontidae). A species complex within Stygiopontius lauensis was studied across five pacific back-arc basins at eight hydrothermal vent fields, with cryptic species being restricted to the basins they were sampled from. Copepod populations from the Lau, North Fiji and Woodlark basins are undergoing demographic expansion, possibly linked to an increase in hydrothermal activity in the last 10 kya. Highly structured populations of Amphiascus aff. varians 2 were also observed from the Lau to the Woodlark basins with populations also undergoing expansion. Less abundant harpacticoids exhibit little to no population structure and stable populations. This study suggests that similarities in genetic structure and demography may arise in vent-associated copepods despite having different life history traits. As structured meta-populations may be at risk of local extinction should major anthropogenic impacts, such as deep-sea mining, occur, we highlight the importance of incorporating a trait-based approach to investigate patterns of genetic connectivity and demography, particularly regarding area-based management tools and environmental management plans.

Mots clés: diversity; copepods; hydrothermal vents; COI barcoding; population genetics

Domaines: Sciences de l'environnement; Sciences du Vivant [q-bio]

Coral Diaz-Recio Lorenzo, Tasnim Patel, Eve-Julie Arsenault-Pernet, Camille Poitrimol, Didier Jollivet, et al.. Highly structured populations of deep-sea copepods associated with hydrothermal vents across the Southwest Pacific, despite contrasting life history traits. PLoS ONE, 2023, 18 (11), pp.e0292525. ⟨10.1371/journal.pone.0292525⟩. ⟨hal-04283353⟩