First account of echinoderid kinorhynchs from Brazil, with the description of three new species

Abstract

As an outcome of the workshop “Taxonomy and Diversity of Marine Meiofauna”, arranged by CEBIMar in Sao Sebastiao, Brazil, the three first Brazilian species of the kinorhynch genus Echinoderes are described. Echinoderes ajax sp. nov. is a subtidal species characterized by four pairs of tubes on segment 2, one pair of tubes in lateroventral position on segment 5, and one pair in laterodorsal position on segment 10. A minute spine is present in middorsal position of segment 4 only, and there are lateroventral spines on segments 6–8. The new species shows most resemblance to E. cantabricus, E. capitatus, and E. isabelae. The second species, E. marthae sp. nov. is intertidal and has no spines, besides the lateral terminal ones. Tubes are present in lateroventral positions on segments 5 and 8, in laterodorsal positions on segment 8, and in subdorsal positions on segment 10, but the latter only in males. The enlarged sieve plates and lack of lateral terminal accessory spines in females clearly places the new species inside the Echinoderes coulli species group. The third new species, Echinoderes astridae sp. nov., is subtidal, and characterized by middorsal spines on segments 4 and 6, ventrolateral tubes on segment 2, lateroventral tubes/spines on segments 5–9, and sublateral tubes on segment 8. In addition, the species has very conspicuous glandular cell outlets of type 2 in subdorsal and sublateral positions of segment 2. The species shows very close resemblance to E. bispinosus, and the two species are basically only distinguished by the sublateral tubes on segment 8, present only in the new species. The close resemblance prompted a re-examination of the type series of E. bispinosus, and light microscopical documentation for this species is presented for the first time.