Setaphyes algarvensis González-Casarrubios & Cepeda & Pardos & Neves & Sánchez 2022, sp. nov.
Creators: name: González-Casarrubios, Alberto
name: Cepeda, Diego
name: Pardos, Fernando
name: Neves, Ricardo C.
name: Sánchez, Nuria
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Kinorhyncha
Allomalorhagida
Echinorhagata
Pycnophyidae
Setaphyes
Setaphyes algarvensis

description: Setaphyes algarvensis sp. nov.
urn:lsid:zoobank.org:act: EC8A3AB5-D8E0-46D5-8A07-436FB91199EA
Figs 2–4, Tables 1–2
Diagnosis
Setaphyes with middorsal elevations on segments 1–6, superficially covered by tufts of elongated, thick hairs whose tips sometimes surpass the posterior margin of segment, and middorsal processes on segments 7–9. Paired paradorsal setae on segments 2–7 and 9; seta on segment 8 unpaired. Laterodorsal setae on segments 2–3 and 6–9 in males and 2–9 in females. Paralateral setae on segment 1. Lateroventral setae on segments 2–10 (two pairs on segment 5). Ventrolateral setae on segment 1 in males and 1–3 in females. Ventromedial setae on segments 3–9 in males and 4–9 in females. Small and abundant cuticular scars (likely outlets of glandular cells) scattered throughout the trunk. Lateral terminal spines present, short, slender.
Etymology
The species name, algarvensis, refers to the Algarve, the southern region of Portugal where the new species was found.
Material examined
Holotype PORTUGAL • adult ♂, mounted in Fluoromount G ® on a glass slide; Alvor; 37°07.714′ N, 08°36.329′ W; 16 Dec. 2012; intertidal mud with Zostera sp.; NHMD-921475.
Paratypes PORTUGAL • 13 adult ♂♂, 1 adult ♀, mounted as the holotype; same collection data as for holotype; NHMD-921477–921489 (♂♂), NHMD-921476 (♀).
Additional material
PORTUGAL • 8 adult ♂♂, five of them mounted as the holotype and three mounted for SEM; same collection data as for holotype; UCM Meiofauna Collection.
Description
See Table 1 for measurements and dimensions and Table 2 for a summary of the middorsal cuticular specialization, seta, tube, nephridiopore and sensory spot locations.
HEAD. With retractable mouth cone and introvert. Although two of the examined specimens had the head everted, their structures tend to collapse when mounted for LM; hence, only some details on the
morphology of oral styles and scalids can be provided. Internal part of mouth cone with several rings of inner oral styles; exact number, arrangement and morphology not determined. External part of mouth cone with single ring of nine equally-sized outer oral styles, arranged as one anterior to each introvert sector, except for middorsal sector 6 where style is missing. Each outer oral style composed of single, flexible unit, wider at base, bearing fringed sheath, progressively tapering toward distally pointed tip. Introvert with six transverse rings of scalids and 10 longitudinal sectors defined by arrangement of primary spinoscalids. Primary spinoscalids larger than remaining scalids, each one composed of basal, rectangular, wide sheath and distal, elongated, distally pointed end-piece. Scalids from remaining rings regular-sized, similar in morphology to primary spinoscalids but smaller, also composed of a longer distal end-piece and a shorter basal sheath. Exact number, arrangement and detailed morphology of scalids not determined.
NECK. With four dorsal and two ventral sclerotized placids (Fig. 2A–B). Dorsal placids rectangular, with a slightly convex anterior margin; mesial ones broader (ca 31–33 µm wide at base) than lateral ones (ca 28–30 µm wide at base) (Fig. 2B). Ventral placids (ca 22–23 µm wide at base) morphologically similar to dorsal ones but much more elongated, getting thinner towards lateral sides (Fig. 2A, C).
TRUNK HABITUS. With eleven segments (Figs 2A–D, 3A, 4A, G). Segment 1 with one tergal, two episternal and one trapezoidal, midsternal plate; remaining segments with one tergal and two sternal
cuticular plates (Figs 2A–D, 3A, 4A, G). Tergal cuticular plates slightly bulging middorsally (Fig. 4A). Sternal plates reach maximum width at segment 7, but almost constant in width across trunk. Sternal cuticular plates relatively narrow in ratio maximum width to total trunk length (MSW:TL average ratio = 25.23%), giving the animal a relatively slender appearance. Middorsal elevations on segments 1–6, rectangular, narrow, distally blunted, not projecting beyond posterior margin of segments (Figs 2B, 3B, F, H, 4A, E). Middorsal elevations covered by tufts of elongated, thick cuticular hairs whose tips may surpass posterior margin of segment (Figs 2B, 4A, E). Middorsal processes on segments 7–9, exceeding posterior margin of segment, also covered by tufts of elongated, thick cuticular hairs (Figs 2B, 3L, 4A, I). Middorsal processes progressively longer towards posterior trunk, reaching maximum length on segment 9 (Figs 2B, 4A, I). Paired, paradorsal, intracuticular butterfly- to trident-like atria associated with middorsal structures (Figs 3B, F, H). Glandular cell outlets as minute, dot-shaped, rounded to oval perforations throughout cuticle on segments 1–11 (Figs 2A–D, 3B, D, F–M, 4H); number and position of these structures vary greatly among examined specimens, not showing any specific pattern. Up to three pairs of conspicuous laterodorsal and ventromedial cuticular ridges on segments 2–10 (Figs 2A–D, 3E, H–J). Cuticular hairs acicular, non-bracteate, distributed across trunk on segments 1–10, not following any particular pattern (Fig. 4F, H, J). Pachycycli and ball-and-socket joints conspicuous on segments 2–9, reduced on segments 10 and 11 (Fig. 2A–B). Apodemes on segments 9–10 (Fig. 2A). Primary pectinate fringes finely serrated (Figs 2A–D, 3L, 4A, C–E, G–I); secondary pectinate fringes as wavy, quite inconspicuous single line (Figs 2A–D, 3J, 4H). Muscular scars as conspicuous, rounded to oval, hairless areas in laterodorsal and ventrolateral positions on segments 1–10 (Fig. 2A–D).
SEGMENT 1. Middorsal elevation not projecting beyond posterior margin of segment (Figs 2B, 3B, 4A). Anterolateral margins of tergal plate as triangular, short, wide, distally rounded extensions (Figs 2A–C, 3C–D, 4G). Paired setae in paralateral and ventromedial positions (Figs 2A–C, 3C–E, 4B–C). Two pairs of sensory spots in subdorsal positions; and one pair in paradorsal and ventromedial positions (Figs 2A–C, 3B, D, 4B–C, F). Sensory spots on this and following segments as oval areas with several rows of cuticular micropapillae surrounding a single pore (Figs 2A–D, 3B, D, F–J, L–M, 4B–C, F, I–J).
SEGMENT 2. Middorsal elevation as on preceding segment (Figs 2B, 3F, 4A). Paired setae in paradorsal, laterodorsal and lateroventral position; females with additional, sexually dimorphic pair in ventrolateral position (Figs 2A–C, 3E–G, 4C). Males with sexually dimorphic tubes in ventromedial position (Figs 2A, 3G, 4C, G). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Figs 2A–C, 3F–G, 4C).
SEGMENT 3. Middorsal elevation as on preceding segments (Figs 2B, 3F, 4A). Paired setae in paradorsal, laterodorsal, lateroventral and ventral positions. Additional paired setae in ventromedial position in males and in ventrolateral position in females (Figs 2A–C, 3E–G, 4C). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Figs 2A–C, 3F–G, 4C).
SEGMENT 4. Middorsal elevation as on preceding segments (Figs 2B, 4A). Paired setae in paradorsal (except for a single specimen, NHMD-921488, with unpaired paradorsal seta), lateroventral and ventromedial positions; females with additional, sexually dimorphic pair in laterodorsal position (Figs 2A–B, 4C). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Figs 2A–B, 4C).
SEGMENT 5. Middorsal elevation as on preceding segments (Figs 2B, 3H, 4A, E). One pair of setae in paradorsal (except for one additional male specimen, with unpaired paradorsal seta) and ventromedial positions, and two pairs in lateroventral position; females with additional, sexually dimorphic pair in laterodorsal position (Figs 2A–B, 3H–I, 4D–E). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Figs 2A–B, 3H–I).
SEGMENT 6. Middorsal elevation as on preceding segments (Figs 2B, 4A). Paired setae in paradorsal, laterodorsal, lateroventral and ventromedial positions (except for single specimen, NHMD-921489, with unpaired paradorsal seta) (Figs 2A–B, 4D). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Fig. 2A–B); two specimens with deviation in pattern of sensory spots in this segment: one (NHMD-921475) with two ventral sensory spots on right half of segment (one ventromedial and one ventrolateral) and only ventromedial pair on left half, and another (NHMD- 921486) with one ventromedial sensory spot on left half of segment and without ventral sensory spot on right half of segment.
SEGMENT 7. Middorsal process extending beyond posterior margin of segment (Figs 2B, 4A, I). Paired setae in paradorsal (except for single specimen, NHMD-921487, with unpaired paradorsal seta), laterodorsal, lateroventral and ventromedial positions (Fig. 2A–B). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Fig. 2A–B).
SEGMENT 8. Middorsal process as on preceding segment, slightly longer (Figs 2B, 3L, 4A, I). Unpaired seta in paradorsal position; paired setae in laterodorsal, lateroventral and ventromedial positions (Figs 2A–B, 3L–M, 4I–J). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions (Figs 2A–B, 3L–M, 4I–J).
SEGMENT 9. Middorsal process as on preceding segment, slightly longer (Figs 2B, 4A, I). Paired setae in paradorsal, laterodorsal, lateroventral and ventromedial positions (Figs 2A–B, D, 4I). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventrolateral positions (Figs 2A–B, D, 4I). Nephridiopore in lateroventral position.
SEGMENT 10. Without middorsal cuticular specialization. Paired setae in lateroventral position (Figs 2A– B, D, 3J). Paired sensory spots in subdorsal, laterodorsal and ventrolateral positions (Figs 2A–B, D, 3J, 4I).
SEGMENT 11. Without middorsal cuticular specialization. Tergal plate triangular, with concave and distally pointed posterior margin; sternal plates with pair of ventral extensions distally rounded (Figs 2A–B, D, 3J–K, 4A, G, I). Males with two sexually dimorphic pairs of stout, thick penile spines (Fig. 2A). Short lateral terminal spines, sexually dimorphic in length (LTS/TL average ratio ca 20% in males and ca 10% in females) (2A–B, D, 3A, J–K, 4G).
Statistical analysis (Fig. 5, Table 1)
The comparison of the total trunk length (TL) between Setaphyes algarvensis sp. nov. and S. kielensis revealed statistically significant differences (p <0.01; Fig. 5A). In contrast, significant differences were not found in the relationship between the total trunk length and the length of lateral terminal spines (LTS/TL) of both species (p = 0.86; Fig. 5B). However, due to the broad range observed in the LTS/ TL of S. kielensis (Fig. 5B), the ratio LTS/TL was compared between males and females in order to find sexually dimorphic differences. The statistical analysis revealed highly significant gender-based
differences within this species (p <0.01; Fig. 5C). The LTS/TL seems to present sexual dimorphism in S. algarvensis sp. nov. as well (Fig. 5B, the arrow points out the single female value), but this fact could not be statistically verified due to the fact that only a single female of this species was collected. Therefore, the LTS/TL ratio was only tested between males of both species, which revealed significant differences (p <0.01; Fig. 5D).
description: Published as part of González-Casarrubios, Alberto, Cepeda, Diego, Pardos, Fernando, Neves, Ricardo C. & Sánchez, Nuria, 2022, Setaphyes algarvensis sp. nov., the first description of an allomalorhagid mud dragon (Kinorhyncha: Allomalorhagida) from Portugal (Eastern Atlantic Ocean), pp. 150-165 in European Journal of Taxonomy 821 on pages 153-161, DOI: 10.5852/ejt.2022.821.1803, http://zenodo.org/record/6607880