Ophryotrocha kailae, Zhang & Zhou & Yen & Hiley & Rouse, 2023

Zhang, Dongsheng, Zhou, Yadong, Yen, Nicole, Hiley, Avery S. & Rouse, Greg W., 2023, Ophryotrocha (Dorvilleidae, Polychaeta, Annelida) from deep-sea hydrothermal vents, with the description of five new species, European Journal of Taxonomy 864, pp. 167-194 : 179-181

Ophryotrocha kailae sp. nov.

urn:lsid:zoobank.org:act:FC8AD84C-5C47-49D2-BEC4-55FC04F3DFBC

Fig. 5

Etymology

Named for Kaila Pearson, an expert on another group of vent and seep-associated polychaetes, phyllodocids belonging to Galapagomystides Blake, 1985 .

Material examined

Holotype EAST PACIFIC OCEAN • 1 spec. (anterior fixed in formalin, posterior fixed in ethanol and used for DNA extraction); Southern East Pacific Rise, active hydrothermal vents; 31.151° S, 111.932° W; depth 2237 m; 29 Mar. 2005; Greg Rouse, Nerida Wilson and Robert Vrijenhoek leg.; collecting event: HOV Alvin dive 4094; GenBank: OP311745 (COI); SIO-BIC A14100 .

Paratypes EAST PACIFIC OCEAN • 1 spec. (fixed in ethanol and the posterior end used for DNA extraction); Southern East Pacific Rise, Saguaro Vent Field , active hydrothermal vents; 31.865° S, 112.044° W; depth 2235 m; 28 Mar. 2005; Greg Rouse, Nerida Wilson and Robert Vrijenhoek leg.; collecting event: HOV Alvin dive 4093; GenBank: OP311748 (COI); SIO-BIC A14099 • 1 spec. (fixed in ethanol and the posterior end used for DNA extraction); Southern East Pacific Rise, German Flats Vent Field , active hydrothermal vents; 37.793° S, 110.916° W; depth 2216 m; 22 Mar. 2005; Greg Rouse, Nerida Wilson, Robert Vrijenhoek leg.; collecting event: HOV Alvin dive 4088; GenBank: OP311746 (COI), OP304894 (16S), OP311650 (H3); SIO-BIC A14101 • 1 spec. (fixed in ethanol and the posterior end used for DNA extraction); same collection data as for holotype; GenBank: OP311747 (COI); SIO-BIC A14102 • 1 spec. (fixed in formalin); same collection data as for holotype; SIO-BIC A14103 • 1 spec. (anterior fixed in formalin, posterior fixed in ethanol); same collection data as for holotype; SIO-BIC A14104 .

Description

In life, translucent with light yellow gut and white eggs mid-body, body opaque white after preservation. Body length ~ 4.5 mm with more than 30 segments, similar width through the body, slightly tapering posteriorly ( Fig. 5A ). Eyes not visible. Prostomium rounded, wider than long, with paired short digitiform antennae inserted dorsally, paired digitiform palps inserted ventral-laterally, similar in length with antennae. Peristomium two rings, similar in length to following segments ( Fig. 5A ). Mandibles heavily sclerotized, shafts rod-like, cutting plates curved, with single blunt peak, lateral wings weakly sclerotized ( Fig. 5B ). Maxillae P-type, forceps comb-like, with large main large fang. Two rows of 7 free denticles, posterior most free denticles (D1) comb-like, D2–D7 shovel-shaped ( Fig. 5C ). Parapodia uniramous, acicular lobe with rounded distal margin, dorsal cirri subtriangular, barely extending beyond distal margin of acicular lobe, ventral cirri stubby ( Fig. 5C ). Supra-acicular chaetae simple, distally serrated, tapering into a fang ( Fig. 5D–E ). Sub-acicular chaetae compound, with serrated blades ( Fig. 5D, F ). Sub-acicular chaetal lobe with one simple chaeta ( Fig. 5D, G ). Pygidium with two anal cirri inserted laterally ( Fig. 5A inset).

Distribution

Known only from vents at 2216–2237 m along the southern East Pacific Rise (Pacific Antarctic Ridge).

Remarks

While the DNA data suggests Ophryotrocha kailae sp. nov. is most closely related to O. pruittae sp. nov. ( Fig. 1 ), morphologically it resembles Ophryotrocha akessoni in having similar mandibles with curving cutting plates, which are otherwise not seen in the vent clade that also includes O. charlottae sp. nov., O. jiaolongi , O. marinae sp. nov. and O. pruittae . Ophryotrocha kailae differs from O. akessoni in the form of its head appendages and possibly pygidial cirri ( Table 3 ).

Figures

Fig. 5. Ophryotrocha kailae sp. nov. A. Whole body of living holotype (SIO-BIC A14100); inset shows the posterior end of paratype (SIO-BIC A14099) with pygidial cirri. B. Mandibles of paratype (SIO-BIC A14099). C. Maxillae of paratype (SIO-BIC A14099). D. Parapodium of paratype (SIO-BIC A14102). E. Simple supra-acicular chaetae of paratype (SIO-BIC A14102). F. Compound sub-acicular chaetae of paratype (SIO-BIC A14102). G. Simple sub-acicular chaeta of paratype (SIO-BIC A14102).

Fig. 1. Phylogenetic tree of Dorvilleidae Ophryotrocha Chamberlin, 1919 based on the Maximum Likelihood and Bayesian Inference analysis of the concatenated dataset of three genes. The outgroup, Eunice pennata (Müller, 1776) is not shown. Numbers on the nodes represent bootstrap support (BS) values followed by posterior probability (PP) values. Blank values indicate BS score of less than 50 or PP of less than 0.7. The * symbol indicated BS support was 95% or greater and PP was 1. Orange branches indicate hydrothermal vent lineages showing that vents have been colonized at least 5 × by Dorvilleidae, 3 × within Ophryotrocha Claparède & Mecznikow, 1869. The letters A and B refer to the two main clades of Ophryotrocha.