Teratothyas (Ascoteratothyas) porrigens, Gerecke, 2020

Gerecke, Reinhard, 2020, The early derivative water mites (Acari: Hydrachnidia, superfamilies Eylaoidea, Hydrachnoidea and Hydryphantoidea) of Madagascar, Zootaxa 4727 (1), pp. 1-77 : 55-57

Teratothyas (Ascoteratothyas) porrigens sp. nov.

Fig. 27 a–b

Type series: Holotype ♂, MNHN Ac 1451, MD 118a, 21.10.2001 Maromandia ( Majunga ), left affl. of R Andranamalaza , ca. 1.0 km E from main road, 100 m, riffle, in liquid . Paratypes: same site and date, (2/0/0) slide mounted, Ac 1382; (1/0/0) in liquid, Ac 1452; MD 031b, 18.08.2001 Madiorano (Fianarantsoa), stream crossing the railroad at km 51.2 (W tunnel 18), 650 m, pool, (0/1/1) slide mounted, Ac 1383; MD 037, 20.08.2001 Andrambovato (Fian- arantsoa), large cascade 3 km E from the village, 820 m, (0/1/0) slide mounted, Ac 1384; MD 200, Andringitra National Park (Fianarantsoa), affluent to Cascade de la Reine near campsite, 1979 m, S 22°09’11.3’’, E 046°54’02.2’’, 12.04.2011 (0/2/2) slide mounted, Ac 1386-1387 .

Other material examined: MD 154b, 17.11.2001 Joffreville (M. d’Ambre, Antsiranana), R de Manques in Reserve Fontenay, 550 m, roots, (1/0/0) slide mounted, Ac 1385 .

Diagnosis: Membranous integument papillate. Genital field ( Fig. 27 b ) with acetabula strongly enlarged (L Ac-1, 53–100, 32–44 % genital field L, Ac-2, 68–128, 44–55 %). Palp ( Fig. 27 a ) longer than in other species of the subgenus (total L, P-4 L ♂♂, 234–268, 80–95; ♀♀, 296–352, 105–134), P-4 ventral margin in basal part straight.

Description: Membranous parts of integument with densely-arranged papillae. Genital field ( Fig. 27 b ) with large acetabula (Ac-1 nearly as long as posterior medial plate margin, its posterior end on level of anterior end of Ac-2; L Ac-1, 53–100, 32–44 % genital field L, Ac-2, 68–128, 44–55 %). Genital flaps finely porose, with about 20 setae (longer and dense at anterior and posterior edges, finer and regularly-arranged along central medial margin) together forming a circle, anterolaterally with porose secondary sclerite, anteromedially concave, embracing the longish Ac-1. Plates posterolaterally embracing genital field with a strong, pore-free anterior margin. Leg claws with a very poorly developed, obtuse angled ventral blade.

Gnathosoma ( Fig. 27 a ) slender, ventral margin in proximal part straight, on the level of palp insertion forming an obtuse angle, distal part concave. Chelicera L/H 8.0–10.0. Palp stout, P-1 basally large, distally strongly narrowed, with one pennate dorsal seta; P-2 and -3 distally barely expanding, P-2 bearing three fine dorsal and two strong, pennate, distoventral setae, P-3 with one simple dorsal seta; P-4 relatively short, maximum H basally (here ventral margin straight or in the centre, bearing 4 fine, hair-like setae, one dorsally in the proximal half, three flanking P-5-insertion; P-5 slender, with little curved claws.

Measurements: Male: Idiosoma L/W 830–1050/525–700; coxal field L/W 470–530/490–590; Cx-I+II L/W 470–530/490–590; Cx-III+IV L/W 275–330/180–210; genital field L/W 155–170/160–220; maximum diameter Ac-1, 53–70, Ac-2, 68–75 Ac-3, 53–70, ejaculatory complex L 180–68; gnathosoma L 215; chelicera total L 350– 352, L/H 9.8–10.0; basal segment/claw 1.23–1.29. Palp total L 234–268; L, L/H ratio, relative L [% total L] palp segments: P-1, 35–38, 0.93–1.15, 13–16; P-2, 48–60, 1.52–1.78, 20–22; P-3, 33–43, 1.08–1.13, 14–16; P-4, 80–95, 3.05–3.17, 34–36; P-5, 35–36, 2.2–2.9, 13–16; L ratio P-2/-3, 1.41–1.46, P-2/-4, 0.59–0.63, P-3/-4, 0.41–0.45. Leg segments L/H, L/H ratio: I-L-2, 85–105, 1.55–1.75; I-L-3, 95–103, 1.65–1.71; I-L-4, 145–163, 2.64–2.83; I-L-5, 150–170, 3.00–3.40; I-L-6, 145–175, 3.18–3.22; claw L 45–50. II-L-2, 95–105, 1.52–1.75; II-L-3, 70–105, 1.17– 1.83; II-L-4, 185–210, 3.36–3.82; II-L-5, 178–215, 3.23–3.91; II-L-6, 160–200, 3.50–3.64; claw L 40–45. III-L-2, 85–105, 1.55–2.00; III-L-3, 85–100, 1.70–1.90; III-L-4, 155–188, 3.10–3.75; III-L-5, 145–185, 3.22–3.70; III-L-6, 140–175, 2.95–3.18; claw L 50–53. IV-L-2, 100–125, 1.90–2.27; IV-L-3, 110–135, 2.10–2.45; IV-L-4, 215–258, 4.30–4.68; IV-L-5, 190–235, 4.22–5.22; IV-L-6, 175–215, 3.68–3.91; claw L 50–55. Total L segments 2–6: I-L, 620–715; II-L, 733-790; III-L, 610–753; IV-L, 790–968.

Females: Idiosoma L/W 1250–1580/850–1120; coxal field L/W 600–840/680–1120; Cx-I+II L/W 350–380/243– 270; Cx-III+IV L/W 338–460/302–350; genital field L/W 83–100/240–270; maximum diameter Ac-1, 83–100, Ac- 2, 105–128, Ac-3, 78–86; gnathosoma L 315–380; chelicera total L 400–518, basal segment/claw 1.08–1.31, L/H 7.8–9.0; Palp total L 296–352; L, L/H ratio, relative L [% total L] palp segments: P-1, 43–47, 0.84–1.13, 13–15; P-2, 65–90, 1.64–2.10, 22–25; P-3, 40–43, 0.84–1.03, 12–14; P-4, 105–134, 3.00–3.83, 35–38; P-5, 38–40, 2.00–2.46, 11–14; L ratio P-2/-3, 1.58–2.11, P-2/-4, 0.62–0.67, P-3/-4, 0.32–0.39. Leg segments L/H, L/H ratio: I-L-2, 105– 140, 1.50–2.07; I-L-3, 115–140, 1.64–2.13; I-L-4, 185–234, 2.85–3.47; I-L-5, 200–252, 3.64–4.23; I-L-6, 180–225, 2.77–3.57; claw L 45–55. II-L-2, 125–180, 1.79–2.22; II–L–3, 120–176, 1.78–2.29; II-L-4, 235–315, 3.62–4.32; II-L-5, 230–320, 3.68–5.07; II-L-6, 180–225, 3.07–4.38; claw L 45–58. III-L-2, 105–149, 1.40–2.20; III-L-3, 115– 153, 1.53–2.27; III-L-4, 225–285, 3.33–4.00; III-L-5, 225–279, 3.91–4.77; III-L-6, 215–248, 3.44–3.67; claw L 54–60. IV-L-2, 135–194, 1.80–2.30; IV-L-3, 148–194, 2.03–2.53; IV-L-4, 290–359, 4.14–5.20; IV-L-5, 290–332, 4.46–5.62; IV-L-6, 250–320, 3.85–4.73; claw L 50–63. Total L segments 2–6: I-L, 785–995; II-L, 940–1242; III-L, 885–1103; IV-L, 1113–1382.

Derivatio nominis: porrigens (Latin) , extending–with reference to the protrusible gnathosomal tube.

Remarks: The species is similar to the type species of the subgenus, T. levigata , in general size of the idiosoma and appendages and formation of the genital field (with large acetabula), but differs in the papillate, not smooth membranous integument. The Ac-2 are more strongly enlarged (% genital field L, T. levigata in parentheses): ♂♂, 44–47 (41–42), ♀♀, 49–55 (43). In both sexes, this taxon shows a wide variability of many measurements, and remarkable differences are also found in the shape of P-4 (with maximum H in basal part, MD 037, in the centre of the segment, MD 118a). A male from the northern Montagne d’Ambre (MD 154) is provisionally attributed to T. porrigens . It lies slightly outside the variability range given here, in having slightly shortened Ac-2 (38 % genital flap L), more elongate chelicerae (L/H 11.0) and a proportionally shorter P-4 (relative L 0.33, P-2/-4 ratio 0.71). Further research on the variability of the diverse populations could reveal that T. porrigens is a mix of two or more species.

Habitat: Low and middle order streams, one uncertain record from (temporary?) puddles.

Distribution: Madagascar, endemic. Mostly in forests at middle and low elevation, but in the Andringitra Mountains at nearly 2000 m a.s.l.

Figures

FIGURE 27. Family Teratothyadidae; a.–b. Teratothyas (Ascoteratothyas) porrigens (MD 200), female. a. gnathosoma with distal part of membranous tube lateral, chelicera and palp; b. genital field and surrounding sclerites; c.–f. Teratothyas (Ascoteratothyas) reducta (MD 074) female; c. gnathosoma with chelicera and palp, lateral; d. palp medial; e. integument structure; f. venter.