Echinoderes dujardinii Claparède, 1863, Claparede, 1863

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: 12-20

publication ID

https://doi.org/10.5852/ejt.2020.730.1197

publication LSID

lsid:zoobank.org:pub:857A9432-9083-46B3-B0BF-B34D619EB350

DOI

http://doi.org/10.5281/zenodo.4418975

persistent identifier

http://treatment.plazi.org/id/03C79270-FFA4-570F-B162-FB661EDEFC4F

treatment provided by

Plazi

scientific name

Echinoderes dujardinii Claparède, 1863
status

 

Echinoderes dujardinii Claparède, 1863  

Figs 2–4 View Fig View Fig View Fig ; Tables 3–4 View Table 3

l’Echinodère Dujardin 1851: 158, pl. 3, figs 1–4.

Echinoderes Dujardinii Claparède, 1863: 90–92   , pl. 16, figs 7–13.

Echinoderes dujardinii   – Higgins 1977a: 4–13, figs 1–12. — Sánchez et al. 2012: 26 [South Galicia].

Non Echinoderes dujardinii   – Mari & Morselli 1987: 117. — Sánchez-Tocino et al. 2011: 179–184, figs 1–4, tables 1–2. — Sánchez et al. 2012: 26 [Algeciras, Granada, Murcia, Alicante]. — Ürkmez et al. 2016: 1–8, figs 2–4.

Emended diagnosis

Echinoderes   with short middorsal spines on segments 4 to 8, and lateroventral spines on segments 6 to 9; middorsal spines on segments 7 and 8 might reach posterior margins of their respective segments, but they never extend beyond the margins. Tubes present in lateroventral positions on segments 2 and 5, in lateral accessory positions on segment 8, and in laterodorsal positions on segment 10. Minute glandular cell outlets type 2 in laterodorsal positions on segments 8 and 9; those on segment 9 situated anterior to laterodorsal sensory spots. Tergal extensions of segment 11 short, pointed and well-spaced; sternal extensions short, with ventrolateral seta-like tuft of extended fringe tips. Females with ventromedial female papillae resembling glandular cell outlets type 2 on segments 6 to 8; intracuticular substructure of papillae on segment 6 is crescentic, substructure on segments 7 and 8 is tubular.

Material examined

FRANCE • 18 ♀♀, 24 ♂♂; Roscoff ; 48°43′ N, 003°58′ W; 0 m b.s.l.; 19 Oct. 1973; E. Kozloff leg.; sandy mud (see Higgins 1977a); USNM-53342. Specimens mounted for LM GoogleMaps   .

SPAIN – Atlantic north coast of Spain • 1 ♀, 4 ♂♂; Cantabric Sea , outlet of Eo River; F. Pardos leg.; UCM. – Galician Atlantic west coast of Spain   1 ♀; Arousa ; F. Pardos leg.; UCM   1 ♂; Vigo ; F. Pardos leg.; UCM. – Andalusian Atlantic south coast of Spain   3 ♀♀, 1 ♂; Huelva ; F. Pardos leg.; UCM. Specimens mounted for LM   .

PORTUGAL • 6 ♀♀, 4 ♂♂; Faro, Ria Formosa ; 37°00′ N, 007°49′ W; 0 m b.s.l.; 21 Oct. 2012; R.C. Neves and M. Herranz leg.; mud with Zostera   ; NHMD-616804 to 616807, NHMD-616822 to 616827. Specimens mounted for LM GoogleMaps   .

About 30 specimens from the same locality at Faro were mounted for SEM and stored in the first author’s personal reference collection. Type material was not available. See Table 1 View Table 1 for an overview.

Description

Echinoderes dujardinii   was redescribed by Higgins (1977a), but due to the numerous new details (mainly revealed by SEM), reinterpretations of cuticular structures, and considerable changes in terminology over the past 40 years, we are providing a full description of the species.

Adults with head, neck and eleven trunk segments ( Figs 2A View Fig , 3 View Fig , 4A View Fig ). Trunk with nearly equally broad sternal plates on segments 5 to 10 ( Fig. 2A View Fig ). Lateral terminal spines slender, from 40% to 55% of trunk length. Secondary pectinate fringe formed as one fringed band near anterior segment margin is present on segments 2 to 10. For complete overview of measurements and dimensions of Portuguese and Spanish populations, see Table 3 View Table 3 . Distribution of cuticular structures, i.e., sensory spots, glandular cell outlets, spines and tubes, is summarized in Table 4.

The head consists of a retractable mouth cone and an introvert ( Figs 3 View Fig , 4B View Fig ). Three rings of inner oral styles, apparently with five styles in each ring. The external mouth cone armature consists of nine outer oral styles, each consisting of two joined units and arranged as one style anterior to each introvert sector, except the middorsal sector 6; each outer oral style basally flanked by pair of lateral spikes, followed by more basal V-shaped row of fringe tips, and again followed by even more basal brush-like arch of bristles ( Fig. 4B View Fig ). The introvert sectors are defined by the ten primary spinoscalids in Ring 01 ( Fig. 3 View Fig ). Each primary spinoscalid consists of a basal sheath and a distal end piece with a blunt tip. The sheaths have two distinctively differentiated fringes: a most basal, transverse fringe, and a slightly more distal fringe where the fringe tips bend in a curve near their attachment point, and fuse to the scalid along a longitudinal line, giving the attachment area a conspicuous appearance (see inset Fig. 4B View Fig ). End pieces are smooth and flexible. Rings 02 and 04 have 10 spinoscalids and Rings 03 and 05 have 20. All spinoscalids in these rings are well-developed, and consist of a basal sheath and a pointed end piece. The basal sheaths terminate into fine, fringed margins in spinoscalids of Rings 02 to 05, and those of Ring 03 have in addition a basal median spike ( Fig. 4B View Fig inset). A ring of short fringes extend around the introvert in between spinoscalid Rings 05 and 06. Ring 06 has only six spinoscalids, located in sectors 1, 3, 5, 6, 7, and 9; ring 06 spinoscalids resemble those in preceding sectors, but are much shorter and with densely haired end pieces. Ring 07 has 7 spinoscalids, located as pairs in sectors 3 and 9, unpaired but laterally displaced in sectors 5 and 7 (trichoscalids are taking up the space in the opposite side of each sector), and unpaired but centred in sector 1; ring 07 spinoscalids resemble those in preceding sector but are even shorter.

Described sector-wise ( Fig. 3 View Fig ), sector 1 has spinoscalids arranged as two double diamonds anterior to a single Ring 7 spinoscalid. Sectors 2, 4, 8 and 10 all have spinoscalids arranged as a quincunx, located in between a medial anterior spinoscalid (Ring 02) and a trichoscalid plate. Sectors 3 and 9 have spinoscalids forming double diamonds anterior to a pair of spinoscalids in Ring 7. Sectors 5 and 7 also have spinoscalids forming double diamonds, but anterior to an unpaired, lateral spinoscalid. Sector 6 has spinoscalids arranged as two double diamonds.

The neck has 16 placids, measuring 20 µm in length. The midventral placid is broadest, measuring 15 µm in width at its base, whereas all other are narrower, measuring 11 µm in width at their bases. The trichoscalid plates in the dorsal sectors are composed of a distal part and a slightly broader proximal part, whereas the proximal parts of the ventral trichoscalid plates are much broader. Trichoscalids with trichoscalid plates are present in sectors 2, 4, 5, 7, 8, and 10.

Segment 1 consists of a complete cuticular ring. Sensory spots are located close to the anterior margin in subdorsal, laterodorsal and sublateral positions ( Figs 2B View Fig , 4 View Fig C–D), and slightly more posterior in ventrolateral positions ( Figs 2C View Fig , 4E View Fig ); sensory spots are rounded to oval, with numerous micropapillae, two pores, and often a cilium emerging from one of the pores. Glandular cell outlets type 1 present in middorsal and lateroventral positions ( Fig. 2 View Fig B–C). Dorsal and lateral sides, and posterior half of ventral side, densely covered with cuticular hairs emerging through rounded perforation sites ( Fig. 4 View Fig C–D); an anterior W-shaped area on the ventral side is completely devoid of hairs ( Fig. 4E View Fig ). The posterior segment margin is straight around the segment, terminating into a pectinate fringe with very short, uniform fringe tips.

Segment 2 consists of a complete cuticular ring. Pachycyclus of the anterior segment margin is of medium thickness and not interrupted ( Fig. 2 View Fig B–C). Sensory spots are located in middorsal (but slightly laterally displaced), laterodorsal (twin pair) ( Figs 2 View Fig B–C, 4C–D) and ventromedial positions ( Fig. 4E View Fig ); appearance sensory spots on this and all following segments as those on segment 1, but droplet-shaped. Glandular cell outlets type 1 present in middorsal and ventromedial positions ( Fig. 2 View Fig B–C); and quite well-developed tubes present in lateroventral positions ( Figs 2C View Fig , 4E View Fig ). The segment is densely covered with bracteate hairs. The posterior segment margin is nearly straight; pectinate fringe from middorsal to lateroventral positions with short fringe tips, as on segment 1; fringe tips from lateroventral to ventromedial positions conspicuously longer, and then slightly shorter again between ventromedial positions.

Segment 3, and remaining segments, consisting of one tergal and two sternal plates ( Fig. 2C View Fig ). Pachycyclus of the anterior segment margin of medium thickness, and interrupted only at tergosternal junctions. Sensory spots present in subdorsal, laterodorsal ( Fig. 2B View Fig ) and sublateral positions. Glandular cell outlets type 1 present in middorsal and ventromedial positions. Bracteate cuticular hairs are densely covering the segment from middorsal to ventromedial positions; paraventral parts densely covered by non-bracteate, hair-like extensions, forming a conspicuous shield-shaped area. Pectinate fringe of posterior margin with slightly longer fringe tips on dorsal and lateral sides, compared to those on preceding segment, and conspicuously long tips in lateroventral to ventromedial positions.

Segment 4 with short acicular spine in middorsal position, not reaching the posterior margin of the segment ( Fig. 4F View Fig ); all spines on this segment and until segment 9 with cylindrical proximal part that halfway to the tip begins to taper gradually. Sensory spots present in subdorsal, midlateral ( Figs 2D View Fig , 4F View Fig ) and ventromedial positions; midlateral sensory spots considerably smaller than all other sensory spots on the animals ( Fig. 4F View Fig inset), but they occur consistently in all examined specimens. Glandular cell outlets type 1 present in subdorsal ( Fig. 2D View Fig ) and ventromedial positions. Pectinate fringe of posterior segment margin with long fringe tips from middorsal to ventromedial positions, and then very short again between ventromedial positions. Pachycycli and cuticular hairs as on preceding segment.

Segment 5 with short acicular spine in middorsal position ( Fig. 4F View Fig ), not reaching the posterior margin of the segment, and well-developed tubes in lateroventral positions ( Figs 2E View Fig , 4H View Fig ). Sensory spots present in subdorsal, midlateral ( Figs 2D View Fig , 4F View Fig ) and ventromedial positions. Glandular cell outlets type 1, pachycycli, pectinate fringe of posterior margin and cuticular hairs as on preceding segment.

Segment 6 with short acicular spines in middorsal and lateroventral positions ( Fig. 4F, H View Fig ); middorsal spine does not reach the posterior margin of the segment, whereas lateroventral spines reach pectinate fringe. Sensory spots present in paradorsal, subdorsal, midlateral ( Fig. 4F View Fig ) and ventromedial ( Fig. 4H View Fig ) positions. Females with female papillae with openings, resembling small glandular cell outlets type 2 ( Fig. 4H View Fig inset), in ventromedial positions, close to and lateral to sensory spots ( Fig. 4H View Fig ); the intracuticular structures of the papillae are crescentic with a small protuberance in the curved part of each structure ( Fig. 2E View Fig ). Glandular cell outlets type 1, pachycycli, pectinate fringe of posterior margin and cuticular hairs as on preceding segment.

Segment 7 with short acicular spines in middorsal (one specimen with two spines emerging from the same opening) and lateroventral positions ( Figs 2 View Fig D–E, 4F, H); middorsal spine does not reach the posterior margin of the segment, whereas lateroventral spines reach pectinate fringe. Females with female papillae as on segment 6, but with openings slightly more anterior and lateral to sensory spots ( Figs 2E View Fig , 4H View Fig ); the substructure of these papillae differs from those on preceding segment, and forms instead a small intracuticular tube ( Fig. 2E View Fig ). Sensory spots, glandular cell outlets type 1, pachycycli, pectinate fringe of posterior margin and cuticular hairs as on preceding segment.

Segment 8 with short acicular spines in middorsal and lateroventral positions ( Figs 2 View Fig D–E, 4F, H), both reaching the pectinate fringe of the posterior margin of the segment. Tubes are present in lateral accessory positions ( Fig. 4G View Fig ). Minute glandular cell outlets type 2 present in laterodorsal positions, but very close to the midlateral lines ( Figs 2D, F View Fig , 4G View Fig ). Sensory spots present in paradorsal, subdorsal, and ventrolateral positions. Females with female papillae with same substructure as those on segment 7, but with openings more anterior and closer to midventral line. Glandular cell outlets type 1, pachycycli, pectinate fringe of posterior margin and cuticular hairs as on preceding segment.

Segment 9 with acicular spines in lateroventral positions ( Fig. 4G View Fig ), just reaching the posterior margin of the segment. Sensory spots present in paradorsal, subdorsal, laterodorsal (posterior to glandular cell outlet type 2), and ventrolateral positions. Glandular cell outlets type 1 and 2 ( Figs 2F View Fig , 4G View Fig ) as on preceding segment, but female papillae not present. Paired nephridiopore areas each consists of a small, rounded sieve plate anterior to a single pore that we consider to be part of the nephridial system, present in lateral accessory positions ( Fig. 4G View Fig , inset). Pectinate fringe of posterior segment margin with uniformly long fringe tips around the segment. Pachycycli and cuticular hairs as on preceding segment.

Segment 10 with well-developed laterodorsal tubes near posterior segment margin ( Figs 2 View Fig G–H, 4I– J). Sensory spots present in subdorsal (but very close to paradorsal) positions; males furthermore with sensory spots in ventrolateral positions ( Fig. 4I View Fig ). Glandular cell outlets type 1 present as two longitudinally arranged middorsal ones and in ventromedial positions. The posterior segment margin of the tergal plate is straight, whereas margins of sternal plates are deeply concave ( Fig. 4K View Fig ); fringe tips of pectinate fringe are considerably shorter than those on preceding segments. Pachycycli and cuticular hairs as on preceding segment.

Segment 11 with lateral terminal spines ( Fig. 2A, G View Fig ). Males with three pairs of penile spines ( Figs 2G View Fig , 4 View Fig I–J); all three penile spines resemble each other, with thicker and rigid proximal parts that taper towards more flexible, distal tips; median penile spines slightly thicker than dorsal and ventral ones. Females with short, thin lateral terminal accessory spines ( Figs 2H View Fig , 4K View Fig ). Sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged middorsal ones. The dorsal and most of the ventral side of the segment are densely covered with non-bracteate hair-like extensions. Tergal extensions are well-spaced, short and pointed ( Figs 2 View Fig G–H, 4I, K); sternal extensions short, with ventrolateral seta-like tuft of extended fringe tips ( Figs 2H View Fig , 4I View Fig ).

UCM

USA, Colorado, Boulder, University of Colorado Museum

UCM

University of Colorado Museum of Natural History

Kingdom

Animalia

Phylum

Cephalorhyncha

Class

Kinorhyncha

Order

Cyclorhagida

Family

Echinoderidae

Genus

Echinoderes

Loc

Echinoderes dujardinii Claparède, 1863

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
2020
Loc

Echinoderes dujardinii

Urkmez D. & Pardos F. & Sezgin M. & Karacuha M. E. 2016: 1
Sanchez N. & Herranz M. & Benito J. & Pardos F. 2012: 26
Sanchez-Tocino L. & Tierno de Figueroa J. M. & Lopez-Rodriguez M. J. & Liebanas G. 2011: 179
Mari M. & Morselli I. 1987: 117
1987
Loc

Echinoderes dujardinii

Sanchez N. & Herranz M. & Benito J. & Pardos F. 2012: 26
Higgins R. P. 1977: 4
1977
Loc

Echinoderes Dujardinii Claparède, 1863: 90–92

Claparede A. R. E. 1863: 92
1863
Loc

l’Echinodère Dujardin 1851: 158 , pl. 3, figs 1–4.