Echinoderes, Claparede, 1863

Sørensen, Martin V., Gąsiorowski, Ludwik, Randsø, Phillip V., Sánchez, Nuria & Neves, Ricardo C., 2016, First report of kinorhynchs from Singapore, with the description of three new species, Raffles Bulletin of Zoology 64, pp. 3-27 : 20

Echinoderes sp. 1

Material examined. Two specimens of an unknown species, Echinoderes sp. 1, were collected at station SI-03. One specimen was mounted for SEM, but was useless for examination. The other was mounted for LM ( Fig. 10 A–E), and deposited at the Natural History Museum of Denmark, under catalogue number ZMUC KIN- 855.

Descriptive notes. Female Echinoderes ( Fig. 10A ) with middorsal spines on segments 4 and 6 ( Fig. 10C ), and laterodorsal tubes on segment 10. Ventral side with ventrolateral tubes on segment 2 ( Fig. 10B ), lateroventral tubes on segment 5, lateroventral spines on segments 6, 8 and 9, but not on 7, and lateral accessory tubes on segment 8 ( Fig. 10D ). Tergal extensions, triangular, with curved external margins, and almost straight, serrated/hairy inferior margins ( Fig. 10E ). Glandular cell outlets of type 2 are not present.

The observed spine pattern quite clearly reveals that the species is new to science. Only two other species, namely, Echinoderes bispinosus Higgins, 1982 and Echinoderes astridae Sørensen, 2014 , have their middorsal spines restricted to segments 4 and 6, but both species have lateroventral spines on segments 6 to 9, segment 7 included (see Higgins, 1982; Sørensen, 2014). Echinoderes bispinosus furthermore lacks tubes in any position on segment 8, whereas the tubes on segment 8 in E. astridae are located in sublateral position. Also the lateral spine pattern in Echinoderes sp. 1, with lateroventral spines on segments 6, 8 and 9, but not on 7, is unique among all species of Echinoderes .

With the shared presence of middorsal spines on segments 4 and 6, and a similarity in general habitus, it is not unlikely that Echinoderes sp. 1 represents a Southeast Asian relative to E. bispinosus and E. astridae . Echinoderes astridae is known from São Sebastião in Brazil only ( Sørensen, 2014), whereas E. bispinosus is described from Bermuda ( Higgins, 1982). A species very similar to E. bispinosus was furthermore quite recently reported from Turkey (Sönmez et al., in press), but the geographic distance between Bermuda and the East Mediterranean suggests that the Turkish record represents a similar, but yet new species.

Figures

Fig. 10. Light micrographs showing overviews and details of trunk morphology in female Echinoderes sp. 1, KIN-855 (A–E) and male Echinoderes sp. 2, KIN-856 (F–J). A, ventral overview. B, Neck region and segments 1–3, ventral view. C, segments 4–7, dorsal view. D, segments 5–8, ventral view. E, segments 10–11, ventral view. F, ventral overview. G, Segments 1–3, ventral view. H, segments 4–7, dorsal view. I, segments 5–7, ventral view. J, segments 10–11, ventral view. Abbreviations: gco1, glandular cell outlet type 1; lat, lateral accessory tube; ltas, lateral terminal accessory spine; lts, lateral terminal spine; lvs, lateroventral spine; lvt, lateroventral tube; mds, middorsal spine; te, tergal extensions; vlt, ventrolateral tube.