New species of Echinoderes (Kinorhyncha: Cyclorhagida) from Mediterranean seamounts and from the deep-sea floor in the Northeast Atlantic Ocean, including notes on two undescribed species

Abstract

Two new species of Echinoderes from the Eratosthenes Seamount and a deep-sea station near the Sedlo Seamount are described. Echinoderes multiporus sp. nov. from the Eratosthenes Seamount is characterized by a combination of the presence of middorsal acicular spines on segments 4, 6, and 8, ventrolateral tubes on segment 2, lateroventral tubes on segment 5, lateroventral acicular spines on segments 6-9, midlateral tubes on segment 10, and type-2 glandular cell outlets in subdorsal position on segment 2 and in laterodorsal position on segments 4-9. Echinoderes unispinosus sp. nov. from the deep-sea station differs from its congeners by the combination of middorsal acicular spine on segment 4, lateroventral acicular spines on segments 6 and 7, type-2 glandular cell outlets present in midlateral position on segment 1, in subdorsal, laterodorsal, sublateral, and ventrolateral position on segment 2, in lateral accessory position on segment 5, and in sublateral position on segment 8, and densely aligned pectinate fringe teeth of the primary pectinate fringes similar in width on segments 1-10. In addition, the morphological data of two undescribed species from the Anaximenes Seamount and a deep-sea station near the Sedlo Seamount are given. An undescribed species from the Anaximenes Seamount is morphologically similar to Echinoderes unispinosus sp. nov., but differs in the smaller trunk length, the presence of broader pectinate fringe teeth of the primary pectinate fringe on segment 1, and the absence of ventromedial sensory spots on segment 8. Another undescribed species from the deep-sea station differs from its congeners in the pattern of spines, tubes, and type-2 glandular cell outlets and length of middorsal and lateral terminal spines. New names are not given to both undescribed species in this study, because only one specimen is available for each species, and both of the specimens were damaged during the preparation.

<i>Echinoderes antalyaensis</i> sp. nov. (Cyclorhagida: Kinorhyncha) from Antalya, Turkey, Levantine Sea, Eastern Mediterranean Sea

“…Echinoderes antalyaensis sp. nov. differs from E. multiporus in the presence of lateroventral tubes on segment 2, lateral accessory tubes on segments 5 and 8, lateroventral acicular spines on segment 8, and the absence of type-2 glandular cell outlets (Yamasaki et al 2018a).…”

“…The combination of the presence of middorsal acicular spine only on segment 4 and absence of any spines on segment 9 is a relatively rare character for the genus, which has been found only in nine species: Echinoderes ajax Sørensen, 2014, Echinoderes cantabricus Pardos et al, 1998, Echinoderes maxwelli (Omer-Cooper 1957, E. multiporus, Echinoderes ohtsukai Yamasaki and Kajihara, 2012, Echinoderes regina Yamasaki, 2016, E. rex, Echinoderes serratulus Yamasaki, 2016, and Echinoderes teretis Brown, 1999in Adrianov and Malakhov (1999) (Omer-Cooper 1957Brown 1985;Pardos et al 1998;Lundbye et al 2011;Sørensen 2014;Herranz and Leander 2016;Yamasaki 2016;Yamasaki et al 2018a). Of these nine species, the species belonging to the so called "E. coulli species group" (Sørensen 2014; Yamasaki 2016), i.e., E. maxwelli, E. ohtsukai, E. regina, E. rex, E. serratulus, and E. teretis, are apparently different from E. antalyaensis sp.…”

“…While Echinoderes is found worldwide from polar to tropical regions and from shallow to deep-sea bottoms, the faunistic investigations have been intensively done only in a small part of the world and most regions have been only sporadically investigated or completely untouched. The recent expeditions in such areas still find many new species and the number of the species is increasing nowadays (e.g., Grzelak and Sørensen 2018;Herranz et al 2018;Yamasaki et al 2018a, b).…”

“…The Mediterranean Sea is one of the better-studied regions, with records of 13 species of Echinoderes (Zelinka 1928;d'Hondt 1973;Higgins 1978;Sánchez-Tocino et al 2011;Sánchez et al 2012;Dal Zotto and Todaro 2016;Sönmez et al 2016;Yamasaki et al 2018a). Especially in the western and middle part of the Mediterranean Sea, comprehensive investigations were done around the coast of the Iberian Peninsula by Sánchez et al (2012), in the Bay of Naples and in the Gulf of Trieste by Zelinka (1928), and around the Italian coast by Dal Zotto and Todaro (2016).…”

“…gerardi Higgins, 1978 and Echinoderes cf. bispinosus Higgins, 1982 from the western Turkish coast, and Yamasaki et al (2018a) reported Echinoderes multiporus Yamasaki et al, 2018 from the Eratosthenes Seamount, off Cyprus and one undescribed species from the Anaximenes Seamounts, off Turkey. In addition, Cephaloryncha flosculosa Yıldız et al, 2017 which belongs to Echinoderidae was described from the southwestern coast of Turkey in Yıldız et al (2017).…”