Setaphyes algarvensis, González-Casarrubios & Cepeda & Pardos & Neves & Sánchez, 2022

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), European Journal of Taxonomy 821, pp. 150-165 : 153-161

publication ID	https://doi.org/ 10.5852/ejt.2022.821.1803
publication LSID	lsid:zoobank.org:pub:49E643D8-DE64-4ABA-90EC-6B10198C539F
DOI	https://doi.org/10.5281/zenodo.6610833
persistent identifier	https://treatment.plazi.org/id/956ECB7C-FFD3-FFB1-FD43-86DA9D4CFE5A
treatment provided by	Felipe
scientific name	Setaphyes algarvensis
status	sp. nov.

Treatment

Setaphyes algarvensis sp. nov.

urn:lsid:zoobank.org:act:EC8A3AB5-D8E0-46D5-8A07-436FB91199EA

Figs 2–4 View Fig View Fig View Fig , Tables 1–2 View Table 1 View Table 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 . GoogleMaps

Paratypes PORTUGAL • 13 adult ♂♂, 1 adult ♀, mounted as the holotype; same collection data as for holotype; NHMD-921477–921489 (♂♂), NHMD-921476 (♀) GoogleMaps .

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 GoogleMaps .

Description

See Table 1 View Table 1 for measurements and dimensions and Table 2 View 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 View Fig ). 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 View Fig ). 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 View Fig ).

TRUNK HABITUS. With eleven segments ( Figs 2A–D View Fig , 3A View Fig , 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 View Fig , 3A View Fig , 4A, G). Tergal cuticular plates slightly bulging middorsally ( Fig. 4A View Fig ). 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 View Fig , 3B, F, H View Fig , 4A, E). Middorsal elevations covered by tufts of elongated, thick cuticular hairs whose tips may surpass posterior margin of segment ( Figs 2B View Fig , 4A, E). Middorsal processes on segments 7–9, exceeding posterior margin of segment, also covered by tufts of elongated, thick cuticular hairs ( Figs 2B View Fig , 3L View Fig , 4A, I). Middorsal processes progressively longer towards posterior trunk, reaching maximum length on segment 9 ( Figs 2B View Fig , 4A, I). Paired, paradorsal, intracuticular butterfly- to trident-like atria associated with middorsal structures ( Figs 3B, F, H View Fig ). Glandular cell outlets as minute, dot-shaped, rounded to oval perforations throughout cuticle on segments 1–11 ( Figs 2A–D View Fig , 3B, D, F–M View Fig , 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 View Fig , 3E, H–J View Fig ). Cuticular hairs acicular, non-bracteate, distributed across trunk on segments 1–10, not following any particular pattern ( Fig. 4F, H, J View Fig ). Pachycycli and ball-and-socket joints conspicuous on segments 2–9, reduced on segments 10 and 11 ( Fig. 2A–B View Fig ). Apodemes on segments 9–10 ( Fig. 2A View Fig ). Primary pectinate fringes finely serrated ( Figs 2A–D View Fig , 3L View Fig , 4A, C–E, G–I); secondary pectinate fringes as wavy, quite inconspicuous single line ( Figs 2A–D View Fig , 3J View Fig , 4H). Muscular scars as conspicuous, rounded to oval, hairless areas in laterodorsal and ventrolateral positions on segments 1–10 ( Fig. 2A–D View Fig ).

SEGMENT 1. Middorsal elevation not projecting beyond posterior margin of segment ( Figs 2B View Fig , 3B View Fig , 4A). Anterolateral margins of tergal plate as triangular, short, wide, distally rounded extensions ( Figs 2A–C View Fig , 3C–D View Fig , 4G). Paired setae in paralateral and ventromedial positions ( Figs 2A–C View Fig , 3C–E View Fig , 4B–C). Two pairs of sensory spots in subdorsal positions; and one pair in paradorsal and ventromedial positions ( Figs 2A–C View Fig , 3B, D View Fig , 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 View Fig , 3B, D, F–J, L–M View Fig , 4B–C, F, I–J).

SEGMENT 2. Middorsal elevation as on preceding segment ( Figs 2B View Fig , 3F View Fig , 4A). Paired setae in paradorsal, laterodorsal and lateroventral position; females with additional, sexually dimorphic pair in ventrolateral position ( Figs 2A–C View Fig , 3E–G View Fig , 4C). Males with sexually dimorphic tubes in ventromedial position ( Figs 2A View Fig , 3G View Fig , 4C, G). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Figs 2A–C View Fig , 3F–G View Fig , 4C).

SEGMENT 3. Middorsal elevation as on preceding segments ( Figs 2B View Fig , 3F View Fig , 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 View Fig , 3E–G View Fig , 4C). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Figs 2A–C View Fig , 3F–G View Fig , 4C).

SEGMENT 4. Middorsal elevation as on preceding segments ( Figs 2B View Fig , 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 View Fig , 4C). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Figs 2A–B View Fig , 4C).

SEGMENT 5. Middorsal elevation as on preceding segments ( Figs 2B View Fig , 3H View Fig , 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 View Fig , 3H–I View Fig , 4D–E). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Figs 2A–B View Fig , 3H–I View Fig ).

SEGMENT 6. Middorsal elevation as on preceding segments ( Figs 2B View Fig , 4A). Paired setae in paradorsal, laterodorsal, lateroventral and ventromedial positions (except for single specimen, NHMD-921489, with unpaired paradorsal seta) ( Figs 2A–B View Fig , 4D). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Fig. 2A–B View Fig ); 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 View Fig , 4A, I). Paired setae in paradorsal (except for single specimen, NHMD-921487, with unpaired paradorsal seta), laterodorsal, lateroventral and ventromedial positions ( Fig. 2A–B View Fig ). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Fig. 2A–B View Fig ).

SEGMENT 8. Middorsal process as on preceding segment, slightly longer ( Figs 2B View Fig , 3L View Fig , 4A, I). Unpaired seta in paradorsal position; paired setae in laterodorsal, lateroventral and ventromedial positions ( Figs 2A–B View Fig , 3L–M View Fig , 4I–J). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventromedial positions ( Figs 2A–B View Fig , 3L–M View Fig , 4I–J).

SEGMENT 9. Middorsal process as on preceding segment, slightly longer ( Figs 2B View Fig , 4A, I). Paired setae in paradorsal, laterodorsal, lateroventral and ventromedial positions ( Figs 2A–B, D View Fig , 4I). Paired sensory spots in paradorsal, subdorsal, laterodorsal and ventrolateral positions ( Figs 2A–B, D View Fig , 4I). Nephridiopore in lateroventral position.

SEGMENT 10. Without middorsal cuticular specialization. Paired setae in lateroventral position ( Figs 2A– B, D View Fig , 3J View Fig ). Paired sensory spots in subdorsal, laterodorsal and ventrolateral positions ( Figs 2A–B, D View Fig , 3J View Fig , 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 View Fig , 3J–K View Fig , 4A, G, I). Males with two sexually dimorphic pairs of stout, thick penile spines ( Fig. 2A View Fig ). 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 View Fig , Table 1 View 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 View Fig ). 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 View Fig ). However, due to the broad range observed in the LTS/ TL of S. kielensis ( Fig. 5B View Fig ), 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 View Fig ). The LTS/TL seems to present sexual dimorphism in S. algarvensis sp. nov. as well ( Fig. 5B View Fig , 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 View Fig ).