Echinoderes antalyaensis, Yamasaki & Durucan, 2018

Yamasaki, Hiroshi & Durucan, Furkan, 2018, Echinoderes antalyaensis sp. nov. (Cyclorhagida: Kinorhyncha) from Antalya, Turkey, Levantine Sea, Eastern Mediterranean Sea, Species Diversity 23, pp. 193-207 : 194-200

publication ID	https://doi.org/ 10.12782/specdiv.23.193
publication LSID	lsid:zoobank.org:pub:AC88E333-D010-481F-B068-4BE8A8545EC9
persistent identifier	https://treatment.plazi.org/id/03FA3C75-2178-746B-6E4C-BF8F3AB0C689
treatment provided by	Felipe
scientific name	Echinoderes antalyaensis
status	sp. nov.

Treatment

Genus Echinoderes Claparède, 1863 View in CoL Echinoderes antalyaensis sp. nov. ( Figs 1–8 View Fig View Fig View Fig View Fig View Fig View Fig View Fig View Fig ; Tables 1, 2)

Material examined. Holotype: Adult male ( ZMB 11673), collected from red algae, Laurencia obtusa , at 3 m depth off the Bilem Beach , Antalya, Turkey (36°51′17″N, 30°44′38″E), mounted as glycerol-paraffin slide on a Cobb aluminum frame GoogleMaps . Paratypes: two adult females and two adult males ( ZMB 11674–11677), all collected together with the holotype. Additional material: one adult male, collected together with the holotype, mounted on an aluminum stub for SEM observations ( ZMB 11678).

Diagnosis. Echinoderes with middorsal acicular spine on segment 4 only; laterodorsal tubes on segment 10; lateral accessory tubes on segments 5 and 8; lateroventral tubes on segment 2; lateroventral acicular spines on segments 6–8; without type-2 glandular cell outlets.

Description. Adult with head, neck, and eleven trunk segments ( Figs 1A, B View Fig , 2A, B View Fig , 3A View Fig , 4A View Fig ). Measurements presented in Table 1. Positions of cuticular structures (sensory spots, glandular cell outlets, spines, tubes, and sieve plates) summarized in Table 2.

Head consisting of retractable mouth cone and introvert ( Figs 2A, B View Fig , 3A View Fig ). Distal part of mouth cone with pharynx crown, five inner oral styles in each of ring-03 and ring-02, and one ring of nine outer oral styles ( Figs 2B–E View Fig , 5 View Fig ). Inner oral styles of ring-01 not examined (they covered by ring- 02 and ring-03 inner oral styles and ornaments of basal outer oral styles; Fig. 2D View Fig ). Inner oral styles visible both in SEM and LM specimen with part of pharynx artificially protruded, but number of styles countable only in SEM ( Fig. 2C–E View Fig ). Each outer oral style consists of triangular distal and rectangular basal part ( Fig. 2D, E View Fig ). Outer oral styles with fringe at their bases composed of three to four long spinose processes which bifurcated at its tip. One pair of additional long spinose processes originating slightly more anteriorly and laterally on either side of each outer oral style ( Fig. 2D, E View Fig ). Introvert composed of six rings of spinoscalids and one ring of trichoscalids ( Figs 3A, B View Fig , 5 View Fig ). Ring 01 with ten primary spinoscalids consisting of one basal sheath and one distal end piece ( Fig. 3A, B View Fig ). Each basal sheath with three overlapping fringes. Proximal fringe composed of four short projections between two long lateral ones. Middle fringe with three medial projections, and distal fringe with six to seven branched projections. Distal end pieces of primary spinoscalids longest within all spinoscalids. Rings 02 and 04 with 10 spinoscalids; rings 03 and 05 with 20 spinoscalids ( Figs 3A, B View Fig , 5 View Fig ). Each spinoscalid of rings 02–05 with basal sheath and end piece. Rings 06 not examined in detail, but with at least six spinoscalids. Six trichoscalids attached with trichoscalid plate in sectors 2, 4, 5, 7, 8, and 10 ( Figs 3A, B View Fig , 5 View Fig ). Each trichoscalid covered with long hairs on entire surface.

Neck with 16 placids ( Figs 1A, B View Fig , 3A View Fig , 5 View Fig ). Midventral placid broadest. Remaining placids similar in size. Two trichoscalid plates present ventrally and four dorsally.

Segment 1 consisting of complete cuticular ring ( Fig. 1A, B View Fig ). This and following ten segments with thick pachycyclus at anterior margin of each segment. Sensory spots in subdorsal, laterodorsal, and ventrolateral position ( Figs 1A, B View Fig , 4B View Fig , 6A, E View Fig ). Each sensory spot composed of one central pore, one long cilium, and numerous micropapillae ( Fig. 6C View Fig ). Type-1 glandular cell outlets, comprising numerous small pores, present in middorsal and lateroventral position ( Figs 1A, B View Fig , 4C View Fig , 6A, B, E View Fig ). Cuticular hairs arising from perforation sites covering almost entirely this and following nine segments ( Figs 1A–D View Fig , 4B–D View Fig , 6A, C–F View Fig , 7A–C, E View Fig , 8A–D View Fig ). Posterior part of this segment with primary pectinate fringe, but spinose processes quite small and visible only in SEM observation ( Figs 4B, C View Fig , 6A, E View Fig ).

Segment 2 with complete cuticular ring as segment 1 ( Fig. 1A, B View Fig ). Lateroventral tubes present ( Figs 1A View Fig , 4B View Fig , 6A, E View Fig , 7A View Fig ). Sensory spots present as one pair in middorsal, two pairs in laterodorsal and one pair in ventromedial position ( Figs 1A, B View Fig , 4B, C View Fig , 6A, E View Fig ). Each sensory spot of this and following segments consisting of one central pore and fewer micropapillae than those on segment 1 ( Fig. 6D View Fig ). Type-1 glandular cell outlet present in middorsal and ventromedial position ( Figs 1A, B View Fig , 4B, C View Fig ). Primary pectinate fringe on this and following seven segments with long spinose processes ( Figs 1A, B View Fig , 4B View Fig , 6A, E View Fig ). Spinose processes longest in midlateral to ventrolateral area.

Segment 3 and following eight segments consisting of one tergal and two sternal plates ( Fig. 1A, B View Fig ). Sensory spots present in subdorsal and midlateral position ( Figs 1A, B View Fig , 6A, E View Fig ). Type-1 glandular cell outlets situated in middorsal and ventromedial position ( Figs 1A, B View Fig , 4C View Fig ).

Segment 4 with middorsal acicular spine ( Figs 1B View Fig , 4C View Fig , 6F View Fig ). Type-1 glandular cell outlets present in paradorsal and ventromedial position ( Figs 1A, B View Fig , 4C View Fig ).

Segment 5 with lateral accessory tubes ( Figs 1A View Fig , 4B, D View Fig , 6F View Fig , 7A View Fig ). Sensory spots in subdorsal, midlateral, and ventromedial position ( Figs 1A, B View Fig , 6F View Fig , 7A View Fig ). Type-1 glandular cell outlets in middorsal and ventromedial position ( Figs 1A, B View Fig , 4C View Fig ).

Segment 6 with lateroventral acicular spines ( Figs 1A View Fig , 4D View Fig , 6F View Fig , 7A View Fig ). Sensory spots present in paradorsal, midlateral, and ventromedial position ( Figs 1A, B View Fig , 6F View Fig , 7A View Fig ). Type-1 glandular cell outlets present paradorsally and ventromedially ( Figs 1A, B View Fig , 4C View Fig ).

Segment 7 with lateroventral acicular spines ( Figs 1A View Fig , 4D View Fig , 7B View Fig , 8A, B View Fig ). Sensory spots present in subdorsal, midlateral, and ventromedial position ( Figs 1A, B View Fig , 7B View Fig ). Type-1 glandular cell outlets present middorsally and ventromedially ( Fig. 1A, B View Fig ).

Segment 8 with lateral accessory tubes and lateroventral acicular spines ( Figs 1A, C View Fig , 4D View Fig , 7B–D View Fig , 8A, B View Fig ). Sensory spots present in paradorsal and laterodorsal position, but laterodorsal ones absent only in one out of six observed specimens ( Figs 1B, D View Fig , 7B View Fig ). Type-1 glandular cell outlets present paradorsally and ventromedially ( Figs 1A, B View Fig , 8B View Fig ).

Segment 9 without any spine and tube. Paradorsal, subdorsal, and ventrolateral sensory spots present ( Figs 1A–D View Fig , 7C View Fig , 8A, B View Fig ). Type-1 glandular cell outlets present in paradorsal and ventromedial position ( Fig. 1A–D View Fig ). Small sieve plates present in sublateral position ( Fig. 1A–D View Fig ).

Segment 10 with laterodorsal tubes ( Figs 1B, D View Fig , 7E View Fig ). Length of laterodorsal tubes in males slightly longer than those in females. Subdorsal and ventrolateral sensory spots present ( Figs 1A–D View Fig , 7C, E View Fig , 8D View Fig ). Two middorsal type-1 glandular cell outlets aligned in tandem ( Fig. 1B, D View Fig ). Additional pair of type-1 glandular cell outlets present in ventromedial position ( Fig. 1A, C View Fig ). Spinose processes of primary pectinate fringe thinner and shorter than those on preceding segment ( Fig. 1A–D View Fig ).

Segment 11 with lateral terminal spines ( Figs 1A–D View Fig , 2A View Fig , 4A View Fig , 7E View Fig , 8C, D View Fig ). Three pairs of penile spines present in males ( Figs 1A, B View Fig , 7E View Fig , 8C View Fig ). Dorsal and ventral penile spines long and tube-like, whereas middle ones stout and triangularshaped. One pair of lateral terminal accessory spines present in females ( Figs 1C, D View Fig , 8D View Fig ). Subdorsal sensory spots present ( Fig. 1B, D View Fig ). Type-1 glandular cell outlet present middorsally ( Fig. 1B, D View Fig ). Posterior edge of tergal plate protruding subdorsally, forming pointed tergal extensions ( Figs 1B, D View Fig , 8E, D View Fig ). Posterior edges of sternal plates rounded with thin spinose processes ( Fig. 1A, C View Fig ).

Etymology. The specific epithet is an adjective referring to the type locality of the new species.

Remarks. Echinoderes antalyaensis sp. nov. can easily be distinguished from other congeners by its unique spine/ tube pattern: with middorsal acicular spine on segment 4, laterodorsal tubes on segment 10, lateral accessory tubes on segments 5 and 8, lateroventral tube on segment 2, and lateroventral acicular spines on segments 6–8. The new species is the only species with this spine/tube pattern within Echinoderes .

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, 1999 in Adrianov and Malakhov (1999) ( Omer-Cooper 1957; Brown 1985; Pardos et al. 1998; Lundbye et al. 2011; Yamasaki and Kajihara 2012; 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. nov. in having a conspicuously large sieve plate on segment 9 and in lacking lateroventral tubes on segment 2 as well as lateroventral acicular spines on segment 8. Echinoderes antalyaensis sp. nov. can be distinguished from them, except for E. teretis , in possessing a smaller body size (trunk lengths are ca. 350–370 µm in E. maxwelli , 315–410µm in E. ohtsukai , 451– 503 µm in E. regina , 482–528 µm in E. rex , and 321–359 µm in E. serratulus opposed to 207–264 µm in E. teretis and 231–277 µm in E. antalyaensis ) ( Brown 1985; Lundbye et al. 2011; Yamasaki and Kajihara 2012; SØrensen 2014; Herranz and Leander 2016; Yamasaki 2016. Note: although Omer- Cooper [1957] described that the trunk length of E. maxwelli was 600 µm, the reexamination of the holotypic and one paratypic specimens revealed their trunk lengths are actually ca. 350–370µm [Dr Martin V. SØrensen pers. comm.]; we used the latter in this study).

Echinoderes antalyaensis sp. nov. differs from E. ajax and E. cantabricus in the number and position of tubes on segment 2. Echinoderes antalyaensis sp. nov. has only one pair of tubes in the lateroventral position on segment 2, whereas E. ajax and E. cantabricus possess four pairs on the segment (tubes present in subdorsal, laterodorsal, sublateral, and ventrolateral position in E. ajax , and in laterodorsal, midlateral, sublateral, and ventrolateral position in E. cantabricus ) ( Pardos et al. 1998; SØrensen 2014). In addition, E. antalyaensis sp. nov. can be distinguished from E. cantabricus in the presence of lateral accessory tubes on segment 8 and the absence of midlateral tubes on segment 1 ( Pardos et al. 1998).

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).