High diversity and pan-oceanic distribution of deep-sea polychaetes: Prionospio and Aurospio (Annelida: Spionidae) in the Atlantic and Pacific Ocean

Abstract

Prionospio Malmgren 1867 and Aurospio Maciolek 1981 (Annelida: Spionidae) are polychaete genera commonly found in the deep sea. Both genera belong to the Prionospio complex, whose members are known to have limited distinguishing characters. Morphological identification of specimens from the deep sea is challenging, as fragmentation and other damages are common during sampling. These issues impede investigations into the distribution patterns of these genera in the deep sea. In this study, we employ two molecular markers (16S rRNA and 18S) to study the diversity and the distribution patterns of Prionospio and Aurospio from the tropical North Atlantic, the Puerto Rico Trench and the central Pacific. Based on different molecular analyses (Automated Barcode Gap Discovery, GMYC, pairwise genetic distances, phylogenetics, haplotype networks), we were able to identify and differentiate 21 lineages (three lineages composed solely of GenBank entries) that represent putative species. Seven of these lineages exhibited pan-oceanic distributions (occurring in the Atlantic as well as the Pacific) in some cases even sharing identical 16S rRNA haplotypes in both oceans. Even the lineages found to be restricted to one of the oceans were distributed over large regional scales as for example across the Mid-Atlantic Ridge from the Caribbean to the eastern Atlantic (> 3389 km). Our results suggest that members of Prionospio and Aurospio may have the potential to disperse across large geographic distances, largely unaffected by topographic barriers and possibly even between oceans. Their high dispersal capacities are probably explained by their free-swimming long-lived planktonic larvae.

Abyssal fauna of polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean: Annelida: Spionidae and Poecilochaetidae

“…However, as our current (Fig. 6) and previously published (Neal et al 2018b;Guggolz et al 2020) molecular data suggest, the specimens identified as A. dibranchiata in fact represent genetically distinct species. Three of those species, Aurospio sp.…”

“…Finally, the genetic data available so far suggest that there is no distinction between Aurospio and Prionospio (Fig. 6 this study; Guggolz et al 2020), but currently no molecular data are available from the type localities, preventing firm conclusions.…”

“…Spionidae are particularly abundant in softbottom environment from shallow waters to deep sea and are also commonly found in organically disturbed environments (e.g., Dean 2008). In the deep-sea sediments, Spionidae are well represented both in terms of abundance and species richness (e.g., Glover et al 2002;Paterson et al 2011), with species within the two closely related genera Prionospio Malmgren, 1867 and Aurospio Maciolek, 1981 particularly well represented (Paterson et al 2016;Guggolz et al 2019Guggolz et al , 2020Paiva 2019, 2020). On the other hand, the family Poecilochaetidae Hannerz, 1956 is rather species poor with 32 valid species confined to the single genus Poecilochaetus Claparède in Ehlers, 1875 and none known from the abyssal depths.…”

Eukaryotic Biodiversity and Spatial Patterns in the Clarion-Clipperton Zone and Other Abyssal Regions: Insights From Sediment DNA and RNA Metabarcoding

“…This is confirmed by genetic data in the case of Epistominella exigua (Pawlowski et al, 2007;Lecroq et al, 2009b) and Cibicidoides wuellerstorfi (Burkett et al, 2020). Wide ranges are reported for certain species of harpacticoid copepods (Menzel et al, 2011) and polychaetes (Schüller and Hutchings, 2012;Guggolz et al, 2020), in the latter case with genetic support. At the same time, it is also common for abyssal assemblages of a particular taxon to combine a few dominant, widely distributed species with many more rare species that are found only in one or two samples (e.g., Glover et al, 2002;Wilson, 2017;Washburn et al, 2021).…”

Patterns of Macrofaunal Biodiversity Across the Clarion-Clipperton Zone: An Area Targeted for Seabed Mining

“…Molecular techniques and more careful morphological taxonomy have revealed that many species considered to have wide ranges have been misidentified or were cryptic species (Sun et al, 2016;Alvarez-Campos et al, 2017;Glover et al, 2018;Hutchings and Kupriyanova, 2018;Nygren et al, 2018). DNA barcoding of 16s and 18s rRNA indicates that A. dibranchiata may indeed be pan-oceanic, but many individuals identified morphologically as A. dibranchiata also comprise several species (Guggolz et al, 2020). Abundant polychaete species may be useful to target in monitoring studies since their absence is less likely to be due to under-sampling than other taxa.…”