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

Abstract

This paper represents a continuation of taxonomic publications on the benthic fauna of polymetallic nodule fields in the eastern Clarion-Clipperton Zone (CCZ) using material collected during baseline environmental survey work targeting two exploration contract areas (“UK-1” and “OMS”) and one Area of Particular Environmental Interest, “APEI-6.” Families Poecilochaetidae Hannerz, 1956 and Spionidae Grube, 1850 of the annelid suborder Spioniformia were studied here. Taxonomic data are presented for 25 species from 98 records as identified by a combination of morphological and genetic approaches. Although sub-optimal morphological condition can prevent new species being formally described, it is essential that morphological, molecular, and voucher data are made available for future surveys. Descriptions of two new species—Poecilochaetus brenkei sp. nov. and Laonice shulseae sp. nov.—increase the number of formally described new annelid species from the areas targeted in this study to 15 and CCZ-wide to 46. We also discuss the commonly reported “cosmopolitan” deep-sea spionid Aurospio dibranchiata Maciolek, 1981, which we show represents several genetically distinct species (three of these from CCZ area alone) but without reliable morphological characters to separate them. Molecular data provide evidence that 15 out of 25 species reported here have a wide distribution within the eastern CCZ and that Aurospio sp. “NHM_2186” and the known species Prionospio amarsupiata Neal & Altamira in Paterson et al. 2016 may be cosmopolitan. Lastly, the molecular data provide insights into relationships within Spioniformia, suggesting that both Poecilochaetidae and Trochochaetidae belong within Spionidae.

Abyssal fauna of polymetallic nodule exploration areas, eastern Clarion-Clipperton Zone, central Pacific Ocean: Amphinomidae and Euphrosinidae (Annelida, Amphinomida)

“…Our main objective has been to provide taxonomic hypotheses on macrofaunal annelids collected from the targeted areas within the CCZ based on morphology and molecular data. These data build up on previous taxonomic work on annelids from the target areas ( Wiklund et al 2019 ; Drennan et al 2021 ; Neal et al 2022 ) as well as wider CCZ area ( Janssen et al 2015 ; Blake 2019 ; Bonifácio and Menot 2019 ) and ultimately provide further insights into annelid species distribution in the deep-sea realm. Up to this date, 52 annelid species have been formally described from CCZ , with the focus on families Spionidae ( Paterson et al 2016 ; Neal et al 2022 ), Orbiniidae ( Blake 2017 , 2020 ), Polynoidae ( Bonifácio and Menot 2019 ), Cirratulidae ( Blake 2016 , 2019 ), Opheliidae , Scalibregmatidae , and Travisiidae ( Wiklund et al 2019 ), Syllidae ( Maciolek 2020 ) and Nereididae ( Drennan et al 2021 ).…”

“…To summarise, the number of DNA sequences for benthic faunal groups from the CCZ available on GenBank are growing, representing echinoderms (e.g. Glover et al 2016a ; Christodoulou et al 2020 ), cnidarians ( Dahlgren et al 2016 ), molluscs ( Wiklund et al 2017 ), annelids ( Janssen et al 2015 ; Bonifácio and Menot 2019 ; Wiklund et al 2019 ; Guggolz et al 2020 ; Drennan et al 2021 ; Neal et al 2022 ), poriferans ( Lim et al 2017 ) and crustaceans (e.g. Janssen et al 2015 ; Kaiser et al 2018 ; Bribiesca-Contreras et al 2021 ; Mohrbeck et al 2021 ).…”

Biodiversity, biogeography, and connectivity of polychaetes in the world's largest marine minerals exploration frontier

“…Details of DNA extraction, amplification, sequence alignment, and phylogenetic methods can be found in Appendix S1. Sequences of the mitochondrial 16S rRNA (16S) and cytochrome c oxidase subunit I (COI) genetic markers were supplemented with sequences from Wiklund et al (2019), Drennan et al (2021), Wiklund et al (in press), Neal, Wiklund, Rabone, et al (2022), Neal, Wiklund, Gunton, et al (2022), Janssen et al (2015), Janssen et al (2019), Bonifácio et al (2020), Bonifácio, Neal, and Menot (2021), and Bonifácio, Neal, Omnes, and Menot (2021) available through NCBI GenBank (Altschul et al, 1990) (https://www.ncbi.nlm.nih.gov/genbank/) and BOLD (https://www.boldsystems.org). Full 16S and COI sequence alignments used in analyses can be found on Dryad (Stewart et al, 2023).…”

Checklist of newly-vouchered annelid taxa from the Clarion-Clipperton Zone, central Pacific Ocean, based on morphology and genetic delimitation

“…Based on detailed taxonomic studies that also incorporated molecular data (e.g. Wiklund et al 2019 , Bonifácio and Menot 2019 , Neal et al 2022a , Neal et al 2022b , Bonifácio et al 2021 ), over 80% of the CCZ-collected annelids are likely new to science ( Rabone et al 2023b ). To date, publications from the areas targeted in this study have yielded 60 annelid species from 327 specimen records, of which only 18 species have been formalised as new ( Wiklund et al 2019 , Drennan et al 2021 , Neal et al 2022a , Neal et al 2022b ).…”

“… Wiklund et al 2019 , Bonifácio and Menot 2019 , Neal et al 2022a , Neal et al 2022b , Bonifácio et al 2021 ), over 80% of the CCZ-collected annelids are likely new to science ( Rabone et al 2023b ). To date, publications from the areas targeted in this study have yielded 60 annelid species from 327 specimen records, of which only 18 species have been formalised as new ( Wiklund et al 2019 , Drennan et al 2021 , Neal et al 2022a , Neal et al 2022b ). However, we are left with a problem in that many specimens are in sub-optimal morphological condition and unable, therefore, to be formally described.…”