Echinoderes worthingi Zelinka, 1928

Sørensen, Martin V., Goetz, Freya E., Herranz, María, Chang, Cheon Young, Chatterjee, Tapas, Durucan, Furkan, Neves, Ricardo C., Yildiz, N. Özlem, Norenburg, Jon & Yamasaki, Hiroshi, 2020, Description, redescription and revision of sixteen putatively closely related species of Echinoderes (Kinorhyncha: Cyclorhagida), with the proposition of a new species group - the Echinoderes dujardinii group, European Journal of Taxonomy 730, pp. 1-101 : 50-51

Echinoderes worthingi Zelinka, 1928

Figs 16–17 ; Table 13

Emended diagnosis

Echinoderes with middorsal spines on segments 4 to 8, and lateroventral spines on segments 6 to 9; middorsal spines on segments 4 to 6 are barely reaching posterior segment margins of respective segments, whereas middorsal spine on segment 8 is more than twice as long as any other middorsal spine, extending to the posterior margin of segment 9 or onto segment 10. Tubes present in lateroventral positions on segments 2 and 5, and in laterodorsal positions on 10. Glandular cell outlets type 2 not present. Paradorsal glandular cell outlets type 1 on segment 11. Primary pectinate fringe on ventral sides of segments 1 to 3 very well-developed, in particular on segment 1. Tergal extensions of segment 11 pointed, with tips extending into long, seta-like fringe. Females with ventromedial female papillae formed by conspicuously strong spatulate tubular substructures on segments 7 and 8.

Material examined

FRANCE • 1 ♀; Roscoff ; 48°43′ N, 003°59′ W; <1 m b.s.l.; 19 Oct. 1973; E. Kozloff leg.; sandy mud (see Higgins 1985); USNM-96034 . Specimen mounted for LM .

UNITED KINGDOM • 1 ♂; Plymouth; 50°20′ N, 004°07′ W; 8 m b.s.l.; 10 July 1978; R.P. Higgins leg.; sandy mud (see Higgins 1985); USNM-67282 . Specimen mounted for LM .

SWEDEN • 2 ♀♀; Kungshamn ; 58°20′ N, 011°14′ E; SMNH-155944A , SMNH-155944B • 1 ♀; Tjärnö ; 58°51′ N, 011°09′ E; 2004; G. Giribet leg.; NHMD-644455 . Specimens mounted for LM .

DENMARK • 1 ♀; Hirsholmene ; 57°29′17″ N, 010°38′01″ E; <10 m b.s.l.; 28 Jan. 2001; M.V. Sørensen leg.; shell gravel; NHMD-644454 . Specimen mounted for LM .

SPAIN • 3 ♀♀, 1 ♂; Huelva , El Portil ; 37°07′37″ N, 006°48′54″ W; <1 m b.s.l.; 6 May 2012; M. Herranz, N. Sánchez and F. Pardos leg.; rocks and stones; personal reference collection of M. Herranz. Specimens mounted for SEM .

No type material was available. See Table 1 for an overview.

Description

The appearance of the species generally follows the redescription provided by Higgins (1985), hence the following notes only provide additional information not included in the original description. We could confirm the lack of glandular cell outlets type 2 in this species. Spines and tubes as described by Higgins (1985), with the conspicuously long middorsal spine on segment 8 that extends to the posterior margin of segment 9, or onto segment 10 ( Figs 16F , 17B ). Pectinate fringes on the posterior segment margins on segments 1 to 3 are differentiated into a dorsal half with very minute fringe tips, and a ventral half with long and well-developed fringe tips; especially on segment 1 ( Fig. 17 C–D). On segment 4, all fringe tips are well-developed, except in the laterodorsal parts of the margin, and fringes are well-developed all around the segment margins from segments 5 to 10. Glandular cell outlets type 1 present in middorsal positions on segments 1 to 3 ( Fig. 16B ) and 10 ( Fig. 16I ) (two longitudinally aligned), in subdorsal positions on segments 4 to 9 ( Fig. 16 D–F), in sublateral positions on segment 1 ( Fig. 16C ), and ventromedial positions on segments 2 to 10 (most of these structures are also included in the original description, but generally referred to as ‘subcuticular scars’). An additional, not previously reported pair of paradorsal glandular cell outlets type 1 is present on segment 11 ( Fig. 16I ). Sensory spots were easily observed in most specimens ( Figs 16B, D, F, I , 17A , C–F, H). Their positions are summarized in Table 13. Female papillae are present in ventromedial positions on segments 7 (more lateral) and 8 (more midventral) ( Figs 16E , 17E ). They consist of circular openings, resembling glandular cell outlets type 2 ( Fig. 17E ), and rather strong oblique, spatulate tubular intracuticular substructures ( Fig. 16 G–H). The female from Roscoff (USNM-96034) is a preadult with a very thin cuticle, which explains why Higgins (1985) missed these structures. They are, however, very distinct in the Kattegat specimens ( Fig. 16 G–H). Hair-patterns are as described by Higgins (1985), but opposite to this redescription, perforation sites are usually distinct (expect for the preadult from Roscoff). Laterodorsal tubes on segment 10 are quite long and slender ( Figs 16 I–J, 17G–H). Tergal extensions of segment 11 pointed, and extending into long, flexible seta-like tips, formed by a terminal fringe ( Figs 16 I–J, 17G–H). Sternal extensions rounded, without any particular fringe differentiation ( Figs 16K , 17H ).

Figures

Fig. 16. Light micrographs showing overviews and details of females Echinoderes worthingi Zelinka, 1928. A–F, I–K. Specimen NHMD-644454. G–H. Specimen SMNH-155944A. A. Ventral overview. B. Segments 1 to 3, dorsal view. C. Segments 1 to 3, ventral view. D. Segments 6 to 8, dorsal view. E. Segments 6 to 8, ventral view, showing female sexual dimorphism. F. Segments 8 to 9, dorsal view. G. Detail showing ventromedial female papilla on left sternal of segment 7. H. Detail showing ventromedial female papilla on left sternal of segment 8. I. Segments 10 to 11, dorsal view, showing female sexual dimorphism. J. Segments 10 to 11, focused on tergal extensions and female sexually dimorphic lateral terminal accessory spines. K. Segments 10 to 11, ventral view, showing female sexual dimorphism.

Fig. 17. Light micrographs showing overviews and details of femaleEchinoderes worthingi Zelinka, 1928 (MH, personal reference collection). A. Segment 1, subdorsal view. B. Lateral overview. C. Segments 1 to 2, lateral view; note how the lengths of the pectinate fringe tips change in midlateral position (arrow). D. Segments 1 to 4, ventral view. E. Segments 7 to 8, ventral view, showing female sexual dimorphism. F. Segments 7 to 9, laterodorsal view. G. Segments 9 to 11, subdorsal view, showing female sexual dimorphism. H. Segments 10 to 11, ventral view, showing female sexual dimorphism.