Echinoderes quasae, Herranz & Leander & Grzelak, 2024

Genus Echinoderes View in CoL Clapar`ede, 1863.

3.3.1. Echinoderes quasae sp. nov ( Figs. 4–6 View Fig View Fig View Fig , Tables 3–4)

Zoobank code: urn:lsid:zoobank.org:act:4C9DB4CC-614F-4AD1-94EA-7250C6D5C988 .

Synonymy: Echinoderes cf. obtuspinosus in Boscaro et al. (2022) and Holt et al. (2022).

3.3.1.1. Diagnosis. Echinoderes with spines in middorsal position on segments 4 to 8 progressively longer towards posterior segments, ranging from 26 to 40 μm on segment 4 to 56–72 μm on segment 8, and spines in lateroventral positions on segments 6 to 9 ranging from 23 to 31 μm on segment 6 to 28–37 μm on segment 9. Tubes present in lateroventral positions on segment 5. Glandular cell outlets type 2 in subdorsal, laterodorsal, sublateral and ventrolateral positions on segment 2, subdorsal positions on segment 4, midlateral positions on segment 5, sublateral positions on segment 8, and laterodorsal positions on segment 10. Lateral terminal spines short and stout, ranging from 16 % to 21 % of the trunk length. Females with lateral terminal accessory spines; males with three pairs of penile spines. Segment 11 composed of two tergal and two sternal plates.

3.3.1.2. Etymology. The species name refers to Q ’ uas or Quu ’ as, a significant figure in Nuu-chah-nulth mythology who taught humans how to live in harmony with nature. The Nuu-chah-nulth, also named Nootka, are composed of several indigenous tribes from the West coast of Vancouver Island (British Columbia) whose mythology describes their emergence from a clam shell, symbolizing their deep connection with the ocean.

3.3.1.3. Material examined. Holotypic male collected on July 4th, 2015, from mud at 3 m depth at Grappler Channel in Bamfield, British Columbia, Canada (BAM-14) ( Fig. 1 View Fig , Table 1). DNA was extracted and COI and ITS sequences deposited in GenBank (NCBI) under accession numbers PQ218550 and PQ217840 respectively, the cuticle was mounted in Fluoromount G on a glass slide and deposited at the Natural History Museum of Denmark, under catalogue number NHMD-1785640. Paratypic series include four specimens, two females and two males; all of them collected at the same locality as the holotype and mounted in Fluoromount G on glass slides and deposited at the Natural History Museum of Denmark, under catalogue numbers NHMD-1785641 to NHMD-1785644. A total of ten specimens collected from localities BAM-07 and BAM-14 were mounted for SEM and stored in MH personal reference collection.

DNA sequences were obtained for COI and ITS from five additional specimens, two males and three females, collected in Bamfield stations (BAM-07, 08, 14) deposited in GenBank ( NCBI) and their cuticles kept as hologenophores, mounted in Fluoromount G and deposited at the Natural History Museum of Denmark under catalogue numbers NHMD-1785645 to NHMD-1785649 ( Table 2) .

3.3.1.4. Description. Adults with head, neck and eleven trunk segments ( Figs. 4–6 View Fig View Fig View Fig ). Overview of measurements and dimensions are given in Table 3. Distribution of cuticular structures, i.e., sensory spots,

glandular cell outlets, spines and tubes, are summarized in Table 4.

Neck with 16 placids. Midventral placid broadest, 15 μm in width at the base, whereas all others are narrower, measuring 9 μm in width at their bases ( Fig. 4A–B View Fig , 5 View Fig B-C). The trichoscalid plates are well-developed.

Segment 1 consists of a complete cuticular ring. Sensory spots are located anteriorly on the segment in subdorsal, laterodorsal and ventromedial positions ( Fig. 4A–B View Fig , 5 View Fig B-C, 6B-C). Glandular cell outlets type 1 present in middorsal and sublateral positions. Cuticular hairs lightly scattered around the segment. The posterior segment margin almost straight, terminating in pectinate fringe with well-developed fringe tips; fringe tips uniform and short along dorsal and lateral sides, but markedly longer on the ventral side ( Fig. 6B–C View Fig ).

Segment 2 consists of a complete cuticular ring with visible partial midventral articulation ( Fig. 4B View Fig , 5B View Fig and 6B View Fig ). Glandular cell outlets type 2 present in subdorsal, laterodorsal, sublateral and ventrolateral positions ( Fig. 4A–B View Fig , 5 View Fig B-C, 6B-C). Sensory spots are located in middorsal, subdorsal, midlateral and ventromedial positions ( Fig. 4A–B View Fig , 5 View Fig B-C, 6BC); sensory spots on this and the following segment are small and rounded, consisting of a ring of micropapillae and a central pore. Glandular cell outlets type 1 present in middorsal and ventromedial positions. Pachycyclus of anterior segment margin relatively thick, interrupted in middorsal position. Secondary pectinate fringe present near anterior segment margin of this and following segments. Cuticular hairs relatively long and thick, distributed evenly around the segment, except the ventral side, where patches with short hairs are present in paraventral and ventromedial positions ( Fig. 4B View Fig and 6 View Fig B-C). The posterior segment margin is straight along the dorsal and lateral sides, and the ventral margin is more convex than segment 1. Fringe tips along the lateral and ventral margins narrower than on the preceding segment, yet still well-developed and conspicuous ( Fig. 6B View Fig ); fringe tips along the dorsal margin as on the preceding segment.

Segment 3, and seven following segments, consisting of one tergal and two sternal plates. Sensory spots located in subdorsal and midlateral positions, and glandular cell outlets type 1 in middorsal and ventromedial positions ( Fig. 4A–B View Fig ). Pachycyclus of anterior segment margin of similar thickness as on preceding segment, interrupted middorsally, and at the tergosternal and midsternal junctions, at this and following six segments. Cuticular hairs as on the preceding segment, but with hairless paraventral and midventral regions, but still dense on the tergal plate. The posterior segment margin straight, terminating in pectinate fringe with significantly shorter and narrower fringe tips on ventral side than as on preceding segments.

Segment 4 with a spine in middorsal position ( Fig. 4A View Fig and 5E View Fig ). Glandular cell outlets type 2 present in subdorsal positions ( Fig. 4A View Fig , 5E View Fig and 6F View Fig ). Segment without sensory spots, but with glandular cell outlets type 1 in paradorsal and ventromedial positions. Pachycyclus of anterior segment margin of regular thickness, pectinate fringe and cuticular hairs as on preceding segment.

Segment 5 with a spine in middorsal position and tubes in lateroventral positions ( Fig. 4A–B View Fig , 5E View Fig , 6 View Fig E-F,I). Glandular cell outlets type 2 present in midlateral positions ( Fig. 5E View Fig and 6F View Fig ). Sensory spots located subdorsally and ventromedially, and glandular cell outlets type 1 present in paradorsal and ventromedial positions ( Fig. 4A–B View Fig ). Segment otherwise as segment 4.

Segment 6 with spines in middorsal and lateroventral positions ( Fig. 4A–B View Fig , 5 View Fig D-E, 6E,I). Sensory spots present in subdorsal, midlateral and ventromedial positions, ventromedial pair situated more ventrally than on preceding and following segment ( Fig. 6E View Fig ). Glandular cell outlets type 1 present in paradorsal and ventromedial positions. Tips of pectinate fringe of posterior segment margin as on preceding segments. Cuticular hairs scarcer on the dorsal side, otherwise as on the preceding segment.

Segment 7 with spines in middorsal and lateroventral positions ( Fig. 4A–B View Fig , 5 View Fig D-E, 6E, I). Sensory spots present in paradorsal, midlateral and ventromedial positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions ( Fig. 3D View Fig and 4 View Fig E-I). Segment otherwise as segment 6.

Segment 8 with spines in middorsal and lateroventral positions ( Fig. 4A–B View Fig , 5 View Fig D-E, 6E, I). Glandular cell outlets type 2 located in sublateral positions; glands are conspicuous, bigger than those on preceding segments ( Fig. 6I View Fig ). Sensory spots present in paradorsal positions, and glandular cell outlets type 1 in paradorsal and ventromedial positions. Pectinate fringe of posterior segment margin as on preceding segment. The cuticular hair coverage is sparser compared to the preceding segment.

Segment 9 with spines in lateroventral positions ( Fig. 4B View Fig ). Sensory spots located in paradorsal, subdorsal, midlateral and ventrolateral positions; subdorsal pair situated more anterior than others ( Fig. 6I View Fig ). Glandular cell outlets type 1 present in paradorsal and ventromedial positions. A pair of oval sieve plates present in sublateral positions ( Fig. 6D–I View Fig ). Pectinate fringe of posterior margin on dorsal and lateral sides with markedly shorter and more slender fringe tips. Cuticular hair covering as on the preceding segment.

Segment 10 with glandular cell outlets type 2 in laterodorsal positions ( Fig. 4A–C View Fig , 6 View Fig G-H), and with sensory spots present in subdorsal and ventrolateral positions. Glandular cell outlets type 1 present as two longitudinally arranged ones in middorsal position and a pair in paraventral positions. Cuticular hairs still relatively dense on dorsal and lateral sides, but scarcer on ventral side ( Fig. 6G View Fig ). Pectinate fringe of posterior margin as on preceding segment, but with longer tips in paraventral areas. The margins of the sternal plates extend midventrally.

Segment 11 with a pair of conspicuously stout and relatively short lateral terminal spines ( Figs. 4 View Fig and 5A View Fig , F-H, 6G; Table 3). Females with lateral terminal accessory spines ( Fig. 4C, D View Fig , 5F View Fig , 6H View Fig ); males with three pairs of penile spines with the dorsal and ventral-most penile spines being slender and tubular; median ones are stout and triangular ( Fig. 4A, B View Fig , 5 View Fig G-H, 6G). Sensory spots present in paradorsal positions, glandular cell outlet type 1 located middorsally. The segment is devoid of cuticular hairs, but with short cuticular hair-like structures covering paradorsal area and short fringes covering margins of tergal and sternal plates. Segment composed of two tergal and two sternal plates ( Fig. 4H View Fig ). Tergal extensions triangular. Sternal extensions shorter, not extending beyond the tergal extensions.

3.3.2. Echinoderes sp.1 and sp.2 cryptic species ( Figs. 2 View Fig and 7 View Fig , S 1 View Fig )

3.3.2.1. Material examined. A total of seven specimens of the short morphotype collected in Calvert Island were used for DNA extraction, but only 3 could be successfully sequenced, of which two vouchers were recovered. Two of the specimens were identified as Echinoderes sp.1 and one as Echinoderes sp.2 (voucher lost) ( Table 2). In addition, two specimens collected from Bamfield were also extracted but only one could be sequenced and identified as Echinoderes sp.2 ( Table 2). Sequenced specimen vouchers assigned to species were deposited at the NHMD under accession numbers NHMD-1785650 to NHMD-1785652. Furthermore, two specimens possibly representing Echinoderes sp.1 or sp.2 from Calvert Island, one male and one female, were prepared for SEM and stored in MH personal collection. DNA sequences of COI and ITS genes were deposited in GenBank ( NCBI), see Table 2 for accession numbers .

3.3.2.2. Short description. Echinoderes sp.1 and sp.2 share identical patterns of spines, tubes, glandular cell outlets and morphometrics ( Figs. 2 View Fig and 7 View Fig , Fig. S1 View Fig ). Characterized by the presence of extremely short spines in middorsal position on segments 4 to 8 not surpassing 14 μm with an average of 12 μm ( Figs. 2 View Fig and 7C, J View Fig ), and lateroventral spines on segments 6 to 9 of 13 μm not increasing in length towards posterior segments. Tubes present in lateroventral positions on segment 5. Glandular cell outlets type 2 in subdorsal, laterodorsal, sublateral and ventrolateral positions on segment 2, subdorsal positions on segment 4, midlateral positions on segment 5, sublateral positions on segment 8, and laterodorsal positions on segment 10 ( Fig. 7 View Fig ). Lateral terminal spines short and stout ( Fig. 2 View Fig ). Females with lateral terminal accessory spines ( Fig. 7F View Fig ); males with three pairs of penile spines ( Fig. 7F–K View Fig ). Segment 11 composed of two tergal and two sternal plates.