Ophryotrocha cantabrica Nuñez, Riera & Maggio, 2014

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 : 52-54

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.4570307

persistent identifier

https://treatment.plazi.org/id/03C5B70F-E951-FFB2-FE46-8AEF6A04FBE9

treatment provided by

Plazi

scientific name

Ophryotrocha cantabrica Nuñez, Riera & Maggio, 2014
status

 

Ophryotrocha cantabrica Nuñez, Riera & Maggio, 2014 View in CoL

Figs 4–5 View Fig View Fig

Ophryotrocha cantabrica Nuñez, Riera & Maggio, 2014: 116 View in CoL , figs 1–3 (type locality: Gijón (Asturias), Bay of Biscay, Cantabrian Sea, NE Atlantic, 72–74 m depth).

Material examined

Holotype SPAIN • Bay of Biscay , Cantabrian Sea; 43°37.71′ – 43°38.36′ N, 05°37.59′ – 05°39.78′ W; 72–74 m depth; 15 Jun. 1991; cruise Fauna II; Stn 114A; MNCN 16.0/14704 . GoogleMaps

Paratypes SPAIN • 38 specs; same collection data as for holotype; MNCN 16.01/13633 GoogleMaps .

Other material

MOROCCO • 27 specs (ethanol), 44 specs (formalin), 1 spec. (slide preparation); GoC, Mercator MV; 35°17.916′ N, 06°38.709′ W; 354 m depth; 2 Mar. 2008; Stn 64PE284_12750W; wood substrata; DBUA0002281.01 View Materials GoogleMaps 7 specs (ethanol), 2 specs (formalin); same collection data as for preceding; 19 May 2009; Stn B09-14b_01W; wood substrata; DBUA0002282.01 View Materials GoogleMaps 1 spec. (ethanol), 3 specs (formalin); GoC, Meknès MV; 34°59.091′ N, 07°04.424′ W; 698 m depth; 20 May 2009; Stn B09-14b_03W; wood substrata; DBUA0002282.02 View Materials GoogleMaps .

PORTUGAL • 135 specs (ethanol); WIM, Estremadura Spur; 39°17.295′ N, 10°01.045′ W; 327 m depth; 1 Jun. 2017; Stn PES-ROVL17D01_pick#3W; sunken wood; DBUA0002283.01 View Materials (2 hologenophores and 133 paragenophores) GoogleMaps .

Description

Relatively large specimens in comparison to the majority of the species of Ophryotrocha ( Fig. 3 View Fig ). Largest complete specimen 5.4 mm long and 0.8 mm wide for 35 chaetigers. Body compressed dorsoventrally, wider sub-anteriorly and tapering posteriorly ( Fig. 4A View Fig ). A transversal band of cilia present in the middle of each segment. Prostomium broadly rounded, without eyes. Antennae and palps digitiform, sometimes retracted and with a more globulous appearance, subequal in length. Peristomium achaetous, with two rings subequal in length to the following segments. Mouth opens ventrally on the first peristomial ring ( Fig. 4B View Fig ). Mandibles rod-like; cutting plates straight and toothed; apophyses triangular, extending laterally right beneath the tip of the mandibula ( Fig. 4B, D View Fig ). Maxillae of P-type with a pair of forceps and seven pairs of free denticles (D1–7) ( Fig. 4E View Fig ); forceps and D1 comb-like with 13 large teeth alternating with two small teeth; D2–3 shovel-like, with long distal fang and serrated edge; D4–6 with coarsely serrated edge (~11 teeth); D7 shovel-like, broader than the others and with smaller and more numerous teeth (~40). Parapodia uniramous, with broadly conical acicular lobes, long digitiform pre-chaetal lamellae (in median parapodia), conical sub-acicular lobes slightly shorter than pre-chaetal lamellae, conical ventral cirri shorter than sub-acicular lobes, and ovoid to piriform dorsal cirri as long as pre-chaetal lamellae in anterior parapodia and greatly increasing in size posteriorly ( Fig. 4A View Fig ). Protruding acicula of sub-acicular lobes very thin and short. Supra-acicular chaetae simple, serrated, tapering distally to a thin pointed hook ( Fig. 4F View Fig ). Sub-acicular chaetae compound with serrated bidentate blades; secondary tooth tiny and difficult to see ( Fig. 4G View Fig ). Pygidium with terminal anus, two cirriform anal cirri inserted laterally and one short median cirrus ( Fig. 4C View Fig ).

Remarks

Ophryotrocha cantabrica was originally described from the Cantabrian Sea at 72–74 m depth ( Nuñez et al. 2014. The holotype and paratypes were examined during this study and found to be similar in size ( Fig. 3 View Fig ) and morphology to the material from GoC and WIM. Only the sub-acicular chaetae of the GoC and WIM specimens seem to have somewhat thicker and shorter blades ( Fig. 5D View Fig ) but this was not considered significant enough to establish a different species. Nuñez et al. (2014) described and illustrated the mandibulae of this species as being distally slightly bifid without serration on the anterior edge. However, a thorough examination of all the specimens (including type material) revealed that the mandibles are often broken at the tip ( Fig. 5A View Fig ), giving the appearance illustrated in the original description ( Nuñez et al. 2014: fig. 3a). In fact, when not broken, the mandibles present a ridge of small teeth on its distal edge ( Fig. 4D View Fig ). Also in the forceps and denticle 1 of the maxillary apparatus, the large teeth were found to alternate with two small teeth ( Figs 4E View Fig , 5B View Fig ). The phylogenetic analysis segregates this species from the others within the tree ( Fig. 2 View Fig ), but there are no DNA sequences from the type material to compare with. The two sequenced specimens were from WIM, the K2P value from the H3 alignment between the two specimens is 0.00 and the K2P value to the nearest species in the tree, O. batillus Wiklund et al., 2012 , is 0.10. This study extends the geographic and bathymetric distribution of O. cantabrica to WIM and GoC, where it was the most abundant species, and to a depth of 698 m. It is noteworthy that all our specimens were associated with wood samples only and not with alfalfa grass.

Ecology and distribution

NE Atlantic: from the Cantabrian Sea (Bay of Biscay) to the Gulf of Cadiz (Moroccan Margin). Found in muddy sand, 72–74 m depth, in the Cantabrian Sea ( Nuñez et al. 2014), and in wood substrata, 327–698 m depth, at the West Iberian Margin and Gulf of Cadiz (present study).

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Eunicida

Family

Dorvilleidae

Genus

Ophryotrocha

Loc

Ophryotrocha cantabrica Nuñez, Riera & Maggio, 2014

Ravara, Ascensão, Wiklund, Helena & Cunha, Marina R. 2021
2021
Loc

Ophryotrocha cantabrica Nuñez, Riera & Maggio, 2014: 116

Nunez J. & Riera R. & Maggio Y. 2014: 116
2014
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