Ophryotrocha geoffreadi, Ravara, Ascensão, Wiklund, Helena & Cunha, Marina R., 2021

Ravara, Ascensão, Wiklund, Helena & Cunha, Marina R., 2021, Four new species and further records of Dorvilleidae (Annelida, Polychaeta) from deep-sea organic substrata, NE Atlantic, European Journal of Taxonomy 736, pp. 44-81 : 56-59

publication ID

https://doi.org/ 10.5852/ejt.2021.736.1251

publication LSID

lsid:zoobank.org:pub:68249639-5FAD-4860-A2EA-0D34690C10FC

DOI

https://doi.org/10.5281/zenodo.4570311

persistent identifier

https://treatment.plazi.org/id/F5023AAF-791B-47A3-90A2-824D50CC4826

taxon LSID

lsid:zoobank.org:act:F5023AAF-791B-47A3-90A2-824D50CC4826

treatment provided by

Plazi

scientific name

Ophryotrocha geoffreadi
status

sp. nov.

Ophryotrocha geoffreadi View in CoL sp. nov.

urn:lsid:zoobank.org:act:F5023AAF-791B-47A3-90A2-824D50CC4826

Fig. 7 View Fig

Etymology

The species is named after Dr Geoffrey Read, the chief taxonomic editor of Polychaeta at the World Register of Marine species (WoRMS) and founder of the Annelida mailing list. His tireless work in both these initiatives is an immense and invaluable aid to all polychaetologists.

Material examined

Holotype MOROCCO • complete spec. (ethanol), 0.94 mm long, 0.17 mm wide, 16 chaetigers; GoC, Meknès MV; 34°59.091′ N, 07°04.424′ W; 698 m depth; 20 May 2009; Stn B09-14b_03W; wood substrata; NHMUK 2020.1512 About NHMUK . GoogleMaps

Paratypes MOROCCO • 31 specs (formalin); same collection data as for holotype; NHMUK 2020.1513 About NHMUK GoogleMaps 1 spec. (ethanol), 2 specs (slide preparation); same collection data as for holotype; DBUA0002286.02 View Materials GoogleMaps .

Other material

MOROCCO • 5 specs (ethanol); same locality as for holotype; 20 May 2009; Stn B09-14b_03A; alfalfa substrata; DBUA0002286.03 View Materials (1 hologenophore, 4 paragenophores) GoogleMaps 2 specs (ethanol), 13 specs (formalin); GoC Darwin MV; 35°23.523′ N, 07°11.513′ W; 1100 m depth; 19 May 2009; Stn B09- 14b_02A; alfalfa substrata; DBUA0002286.04 View Materials GoogleMaps 9 specs (ethanol), 1 spec. (slide preparation), 5 specs (formalin); same collection data as for preceding; 19 May 2009; Stn B09-14b_02W; wood substrata; DBUA0002286.05 View Materials GoogleMaps .

Description

Relatively small specimens compared to most species of Ophryotrocha . Most of the larger specimens are damaged or incomplete and were not measured. Measured specimens 0.73 to 1.46 mm long and 0.19 mm wide, for 17 to 25 chaetigers ( Fig. 3 View Fig ). Body dorso-ventrally flattened, wider anteriorly and tapering posteriorly. Prostomium broadly rounded ( Fig. 7A View Fig ), without eyes. Antennae and palps short, cirriform; antennae inserted mid-dorsally on the prostomium; palps inserted laterally. Peristomium achaetous, with two rings of length similar to the following segments. Jaw apparatus brown, well visible through the specimen body. Mandibles rod-like, with straight, serrated cutting edge (with around 8 teeth in smaller specimens, Fig. 7B View Fig ) and weakly sclerotized apophyses, shorter than cutting edges. In larger specimens, the cutting edge teeth are usually worn and the apohyses are enlarged longitudinally ( Fig. 7E View Fig ). Maxillae of P-type (also after moulting) with asymmetric forceps; left forceps narrow and finely toothed (up to 35? teeth), right forceps wider and coarsely toothed (~15 teeth) ( Fig. 7F View Fig ); seven free denticles (D1–7; Fig. 7C, F View Fig ), D1 comb-like coarsely toothed, similar to right forceps, D2 shovellike with an outer larger tooth and coarse teeth, D4–6 shovel-like with smaller teeth slightly increasing in number anteriorly, D7 shovel-like, much broader than the others; carrier-like structure with a toothed ridge on each side at the base of the bifurcation ( Fig. 7F View Fig ) and a posteriorly fimbriate handle ( Fig. 7C View Fig ). Parapodia uniramous, with conical acicular lobes, inconspicuous pre-chaetal lamellae, long sub-acicular lobes and conical dorsal cirri inserted sub-distally on the parapodia ( Fig. 7D View Fig ); ventral cirri absent. Subacicular lobes with a short needle-like protruding acicula ( Fig. 7H View Fig ). Chaetae relatively short and stiff; supra-acicular chaetae simple, tapering distally, smooth or very finely serrated, up to 7 per fascicle ( Fig. 7I View Fig ); sub-acicular chaetae compound with sub-distally serrated shafts and falcate, lightly serrated blades ( Fig. 7G View Fig ), up to 7 per fascicle. Pygidium with terminal anus, a pair of short cirriform anal cirri (spherical and almost inconspicuous in smaller specimens) and a median papilla.

Remarks

According to the phylogenetic analysis ( Fig. 2 View Fig ), O. geoffreadi sp. nov. is close to the species O. langstrumpae Wiklund et al., 2012 , O. sadina Ravara, Marçal, Wiklund & Hilário, 2015 , O. cantabrica Nuñez, Riera & Maggio, 2014 , O. scutellus Wiklund, Glover & Dahlgren, 2009 , O. lusa Ravara, Marçal, Wiklund & Hilário, 2015 , O. batillus Wiklund et al., 2012 and O. chemecoli sp. nov. ( Wiklund et al. 2009, 2012; Nuñez et al. 2014; Ravara et al. 2015). However, unlike O. geoffreadi sp. nov., all those species have well-developed parapodial lobes and cirri, and only two of them ( O. langstrumpae and O. cantabrica ) have mandibulae with a straight cutting edge but without membranous apophyses. Three other species that are not included in the phylogenetic analysis have mandibulae with a straight, serrated cutting edge: O. pachysoma Hilbig & Blake, 1991 from the W Atlantic (604–2065 m depth), O. natans Pfannenstiel, 1975 from the Red Sea (intertidal) and O. kagoshimaensis Miura, 1997 from the W Pacific (197 m depth) ( Pfannenstiel 1975; Hilbig & Blake 1991; Miura 1997). Nevertheless, the presence of a membranous apophyse below the cutting edge is not clear for the two latter species, and the cutting edge of the mandibulae of O. pachysoma is much wider and also serrated on its internal border. Furthermore, the maxillary, parapodial and chaetal morphology of all these species is different from that of O. geoffreadi sp. nov.

Ecology and distribution

NE Atlantic: Gulf of Cadiz (Moroccan Margin). Found in experimentally deployed wood and alfalfa substrata, at 698–1100 m depth (this study).

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Eunicida

Family

Dorvilleidae

Genus

Ophryotrocha

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