Teratothyas (s. str.) planipapillata, 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 : 49-51

Teratothyas (s. str.) planipapillata spec. nov.

Fig. 24 c–f

Type series: Holotype ♂, MNHN Ac 1368; MD 109, 08.10.2001 Ankaratra (Antananarivo), Reserve Manjakatompo, riparian spring exp. SE at spring stream N deviation to Analamitana (MD 108), 1850 m, slide mounted, together with one of the following paratype ♂♂ . Paratypes: Same site and date, (3/4/2) slide mounted, Ac 1369-1372; (10/11/0) in liquid, Ac 1446.

Diagnosis: Membranous parts of integument with short, flattened papillae. Genital field ( Fig. 24 c ) with rather long acetabula (relative L Ac-1, 33–40, Ac-2, 44–48 % genital flap); medial genital flap margins in posterior 2/3 slightly convex, their posterior end rounded. Leg claws with basal blade ending in a pointed, distally directed tip ( Fig. 24 d ). Palp ( Fig. 24 e ) relatively slender (L/H ratio P-2, 1.8, P-3, 1.4, P-4, 4.7), P-4 maximum height basally.

Description: Integument papillae well developed, rounded, not prolonged or cannelated. Pores of idiosoma sclerites rather large (<10 per transect on dorsocentralia), inner trabecular structures everywhere prominent. Legs relatively slender, claws with an acute-angled, denticle-like basal blade.

Genital field ( Fig. 24 c ) anterior margin in a trapezoidal bay made up by straight posteromedial margins of Cx-IV and their medially extending sclerite arms, posterior margin embraced by trabecular sclerites forming obtuse lateral angles. Genital flaps finely porose, medial margins straight except for the bay embracing Ac-1, posteromedial edges rectangular, with a rounded tip; about 20 genital setae (longer and dense at anterior and posterior edges, finer and hair-like along central medial margin). Anterolateral secondary sclerite extending under the medial margins of Cx-IV. Ac-1 lateral margin equally rounded, medial margin straight, posteriorly pointed; Ac-2/-3 large and prominent.

Gnathosoma ( Fig. 24 e ) as in T. proceripapillata . Chelicera ( Fig. 24 f ) with a very stout basal segment, L/H ratio 5.3–8.3, basal segment/claw 0.5–0.7. Palp ( Fig. 24 e ) with P-1 basally large, distally strongly narrowed, with one or two pennate dorsal seta(e); P-2 and -3 distally hardly expanding, P-2 bearing four fine dorsal setae, the two typical distoventral setae very strong, P-3 with three simple dorsal setae; P-4 maximum H in proximal part, ventral and dorsal margins equally converging towards segment tip, bearing the typical 4 fine, hair-like setae, distal margin at the insertion of the pointed distomedial peg seta protruding and pointed; P-5 slender, with barely curved claws.

Measurements: Male: Idiosoma L/W 1040–1050/620–700; coxal field L/W 570–620/510–580; Cx-I+II L/W 320–350/210–220; Cx-III+IV L/W 380–420/270–290; genital field L/W 180–190/170–190; maximum diameter Ac-1, 73–78, Ac-2, 80–90, Ac-3, 68–80, ejaculatory complex L 215; gnathosoma L 250–260; palp total L 340; L, L/H ratio, relative L [% total L] palp segments: P-1, 53, 1.50, 15; P-2, 69, 1.83, 20; P-3, 49, 1.39, 14; P-4, 130, 4.73, 38; P-5, 40, 2.91, 12. Leg segments L/H, L/H ratio: II-L-2, 120–130, 2.09–2.17; II-L-3, 100–110, 1.82–1.91; II-L-4, 180–195, 3.27–3.39. IV-L-4, 250–260, 4.52–4.55;

Females: Idiosoma L/W 1350–1410/910–960; coxal field L/W 700–740/710–730; Cx-I+II L/W 400/240–250; Cx-III+IV L/W 500–510/370–380; genital field L/W 240/260; maximum diameter Ac-1, 80–90, Ac-2, 108–115, Ac-3, 75–105; gnathosoma L 300–460; chelicera total L 495, basal segment/claw 0.74, L/H 8.25; palp total L 388; L, L/H ratio, relative L [% total L] palp segments: P-1, 68, 1.59, 17; P-2, 75, 1.76, 19; P-3, 55, 1.38, 14; P-4, 148, 4.72, 38; P-5, 43, 2.83, 11. Leg segments L/H, L/H ratio: I-L-2, 113, 1.73; I-L-3, 105, 1.62; I-L-4, 165, 2.54; I-L-5, 175, 2.92; I-L-6, 150, 3.00; claw L 45. II-L-2, 140–150, 2.07–2.14; II-L-3, 120–125, 1.78–1.79; II-L-4, 223–235, 3.36–3.42; II-L-5, 225–240, 3.91–4.00; II-L-6, 145–190, 2.42–3.45; claw L 48. III-L-2, 120, 1.85–2.00; III-L-3, 110–113, 1.83–1.88; III-L-4, 205–218, 3.73–3.95; III-L-5, 190–215, 3.45–4.30; III-L-6, 190–195, 3.90; claw L 55. IV-L-2, 153–170, 2.26–2.43; IV-L-3, 170, 2.52–2.62; IV-L-4, 290–315, 4.46–4.85; IV-L-5, 265–280, 4.61–4.67; IV-L-6, 225–230, 3.68–3.91; claw L 58–63. Total L segments 2–6: I-L, 708; II-L, 895–898; III-L, 830–845; IV-L, 1103–1165.

Derivatio nominis: planus (Latin): flat, papillata (Latin): papillate; with reference to the membranous integument structure.

Remarks: Teratothyas planipapillata differs from T. proceripapillata and T. digitata in the formation of the membranous integument, with short, flat papillae, leg claws with a pointed proximoventral blade, and P-4 with maximum H in proximal part. In comparison with T. proceripapillata (idiosoma L ♂♂ <1000, ♀♀ <1250, genital field L ♂♂ <175, ♀♀ <190) it is distinctly smaller in size. With regard to proportions of the palp, T. planipapillata is intermediate between the two species, with a P-4 more slender than in T. proceripapillata , but stouter than in T. digitata –as in the latter species, the distal margin of the segment is acute-angled.

Habitat: Weakly seeping riparian rheohelocrene on the border of a middle order mountain stream.

Distribution: Madagascar, endemic, only known from the type locality at high elevation in the Ankaratra mountains.

Figures

FIGURE 24. Family Teratothyadidae. a.–b. Teratothyas (s. str.) digitata (MD 194), male; a. genital field; b. palp. c.–f. Teratothyas (s. str.) planipapillata (MD 109); c. female genital field; d.–f. male; d. leg claw; e. gnathosoma with palp; f. chelicera.