Polystilifera Brinkmann, 1917

Sagorny, Christina, Döhren, Jörn von, Rouse, Greg W. & Tilic, Ekin, 2022, Cutting the ribbon: bathyal Nemertea from seeps along the Costa Rica margin, with descriptions of 2 new genera and 9 new species, European Journal of Taxonomy 845 (1), pp. 132-174 : 147

Order Polystilifera Brinkmann, 1917

One polystiliferan nemertean was collected at 950 m depth from non-seep seamount habitat at Cocos Canyon (SIO-BIC N263). The specimen is 65 mm long and dorso-ventrally flattened. The body is translucent and coloration is pale pinkish ( Fig. 3D–E ). This reptant hoplonemertean is sister to another undescribed Reptantia Brinkmann, 1917 from the Kuril Islands (500 m depth). Together with three further unidentified hadal reptant hoplonemerteans, this clade is sister to Pelagica Brinkmann, 1917 ( Fig. 6 ). Again, we choose not to name this species as a thorough taxonomic revision of Reptantia is warranted. The histological data set is published herein: https://doi.org/10.5281/zenodo.6375286.

Figures

Fig. 3. Live images of palaeonemerteans, heteronemerteans, and polystiliferous hoplonemerteans collected along the Costa Rica margin. A. Tubulanus cf. lutescens (SIO-BIC N107) (Palaeonemertea). B. Dorsal surface of head region of Tubulanus cf. lutescens (SIO-BIC N233). C. Lineidae (SIO-BIC N254) (Heteronemertea). D–E. Reptantia (SIO-BIC N263) (Polystilifera) dorsal (D) and ventral view (E).

Fig. 6. Maximum likelihood (ML) tree for the polystiliferan supermatrix based on the concatenated four gene dataset (16S, COI, 18S, H3). Black circles indicate nodal support of 100/100/1.0; asterisks indicate nodal support of either 100/ or /1.0. Alternative branches found in the BI analysis are given as blue dotted lines. Sonnenemertes cantelli Chernyshev, Abukawa & Kajihara, 2015 and Micrura callima Sundberg & Gibson, 1995 were used for outgroup rooting. The reptant hoplonemertean specimen collected at the Costa Rica margin is given in bold. Specimen-ID, sampling locality, and depth (for deep-sea species) are provided.