Trematirunella seychellia Kontschán & Ermilov, 2025, sp. nov.
Creators: name: Kontschán, Jenő
name: Ermilov, Sergey G.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Mesostigmata
Trematuridae
Trematirunella
Trematirunella seychellia

description: Trematirunella seychellia sp. nov.
Figs 1, 2, 3, 4, 5
Material examined.
Holotype. • Female. Seychelles, Praslin, 4°20'12"S, 55°44'8"E soil and decaying wood, 27 July 1982, C. Vaucher coll. Paratypes. Ten males and two deutonymphs. Locality and date same as in holotype.
Diagnosis.
Posterior margin of idiosoma rounded. Dorsal setae apically serrate. Setae in row J long, reaching basis of next setae. Surface of female genital shield without sculptural pattern. Ventral setae smooth and long.
Description.
Female (N = 1). Length of idiosoma 635, width at level of coxae IV 462, colour reddish-brown. Shape of idiosoma oval, posterior margin rounded.
Dorsal idiosoma (Figs 1, 5 A – D). Marginal and dorsal shields completely separated. Dorsal shield covered by oval pits (ca 9–10 × 6–8) with wide court. Dorsal setae apically serrate (Fig. 3 A), short (ca 33–35) in anterior and lateral areas and long (ca 82–97) in central area. Two pairs of robust and sword-like (ca 95–102 long) setae situated on caudal area of dorsal shield. Marginal shield with an anterior incision, its inner margin undulate in anterior area. Inner margin of caudal area of marginal shield bearing numerous, long (ca 55–105 long) and smooth setae. Marginal setae long (ca 82–94) and apically serrate (Fig. 3 B).
Ventral idiosoma (Fig. 2). Five pairs of smooth and needle-like (ca 10–22 long) sternal setae presented. Setae st 1 inserted at level of anterior margin of coxae II, st 2 at level of mid-coxae II, st 3 at level of anterior margin of coxae III, st 4 at level of posterior margin of coxae III, st 5 at level of posterior margin of coxae IV. Sternal shield with web-like sculptural pattern, one pair of lyriform fissures situated close to st 1. Preanal suture present. Seven pairs of ventral setae smooth and needle-like, setae anterior to preanal suture shorter (ca 55–60) and narrower than setae posterior to preanal suture (ca 98–105). Surface of ventral shield ornamented by large oval pits. One pair of poroids situated close to first ventral setae, and one pair of lyriforms fissured on lateral area of ventral shield. Anal opening oval (34 long and 12 wide), anal valves smooth, without euanal setae. Adanal setae (ad 1 and ad 2) ca 36–44 long and needle-like. Postanal seta similar in shape and length to adanal setae. Genital shield scutiform (length 162, basal width 97) with long (ca 44) anterior prolongation. Surface of female genital shield without sculptural pattern. Stigmata situated between coxae II and III. Peritremes with hook-shaped prestigmatid part, poststigmatid part short and straight. Pedofossae weakly developed. Tritosternum with vase-like base, with two pairs of apical spines. Its laciniae marginally pilose and apically trifurcated (Fig. 3 C).
Gnathosoma (Fig. 3 D). Corniculi with three lateral teeth, internal malae narrow and smooth. Hypostomal setae h 1 smooth and needle-like (ca 29–32), h 2 (ca 21–23), h 3 (ca 37–39) and h 4 (ca 41–43) marginally serrate. Deutosternal groove narrow, without denticles. Epistome marginally serrate (Fig. 3 E), basal part wider than apical part. Chelicerae with internal sclerotized nodes (Fig. 3 F). Both digits of chelicerae bearing 3–4 teeth, movable digit as long as fixed digit (ca 45–52 long). Both palp trochanter setae pilose, other setae on palp segments smooth.
Legs (Fig. 3 G – J). Length of legs (from base of coxae to apex of tarsi): I 280–283, II 245–248, III 270–272, IV 283–284. Leg I with ambulacral claws; all setae smooth, long and need-like. Femora I – IV with ventral flaps.
Male (N = 10). Body 630–637 long and 450–460 wide.
Dorsal idiosoma. As in female.
Ventral idiosoma (Figs 3 K, 5 E). Intercoxal area, with sternal setae and genital shield, as in Fig. 3 K. Sternal setae ca 23–25 long, smooth and needle-like. Setae st 1 situated at level of mid-coxae II, st 2 and st 3 at level of anterior margin of coxae III, st 4 at level of posterior margin of coxae II, st 5 posterior to genital opening. Surface of sternal shield covered by oval pits, but a U-shaped reticulate sculptural pattern visible anterior and lateral to genital opening. One pair of large poroid-like structure situated between st 2 and st 3 and two small pairs of poroids situated posterior to large ones. Genital shield rounded, but anterior margin a little straight, ca 32–34 long and 27–29 wide. Its surface smooth, without eugenital setae and situated between coxae III – IV.
Other characters as in female.
Deutonymph (N = 2). Idiosoma 450–455 long and 346–350 wide.
Dorsal idiosoma (Fig. 4 A). Dorsal shield oval, its surface covered by oval pits with wide court. Dorsal setae smooth and apically serrate in different sizes (ca 18–72 long). Caudal part of dorsal shield with four pairs of anterior and long (ca 85–87 long) and four pairs of posterior and short (ca 27–30 long) robust setae. Marginal shield without sculptural pattern and bearing ca 72–88 long apically serrate setae.
Ventral idiosoma (Fig. 4 B). Sternal shield vase-shaped, covered by oval pits and bearing four pairs of needle-like setae (ca 22–24 long). Surface of peritrematal and metapodal shields with web-like sculptural pattern. Prestigmatid part of peritremes long with two bends, postsitgmatid part short and straight. Anal shield wider (203–207) than long (78–82) and bearing one pair of shorter (ca 45–47 long) and one pair of longer (ca 86–89 long) setae. Surface of anal shield with web-like sculptural pattern. Anal opening wider than long (10–12 × 17–18) and bearing one pair of short (ca 16–17) and needle-like setae.
Protonymph and larvae unknown.
Etymology.
The name of the new species refers to the islands, where the species was collected.
Note.
The most important differences among the known Trematirunella species are summarized in Table 1.
Zoogeographical note.
Trematirunella species have been reported only from the Philippines and the Seychelles. The distance between the two known localities is considerable. Still, there is no information about the occurrence of the members of this genus in some of the most intensively studied countries (like Malaysia, Indonesia, and Thailand) (see Kontschán 2024).
description: Published as part of Kontschán, Jenő & Ermilov, Sergey G., 2025, A new remarkable representative of Uropodina mites from Seychelles (Acari, Mesostigmata, Trematuridae), pp. 289-296 in ZooKeys 1229 on pages 289-296, DOI: 10.3897/zookeys.1229.142822