Teratothyas (s. str.) proceripapillata, 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 : 45-48

Teratothyas (s. str.) proceripapillata sp. nov.

Fig. 23

Type series: Holotype ♂, MNHN Ac 1350, MD 011d, 21.07.2001 Anjozorobe (Antananarivo), Ravoandrina, R Ampanakamonty near campsite, 1280 m, upper course (undissected, slide mounted together with a dissected male) . Paratypes: same site and date, (2/4/0) slide mounted, Ac 1351-1353; MD 011c (same site and date, middle course), (0/1/0) slide mounted, Ac 1354; MD 015b, 25.07.2001 Anjozorobe (Antananarivo), Ravoandrina, R Andohana Andreba (affl. of R Ampanakamonty), 1250 m, riffle, (2/0/0) slide mounted, Ac 1356; MD 016a, 27.07.2001 Anjozorobe (Antananarivo), Ravoandrina, R Anjajely (affl. of R Ampanakamonty, downstream from affl. MD 015), 1250 m, stones, (1/0/0) slide mounted, Ac 1357; MD 167, 21.11.2001 Joffreville (M. d’Ambre, Antsiranana), riparian rheocrenes at R Antomboka downstr. large cascade, 850 m, (6/2/0) in liquid, Ac 1443 .

Other material examined:MD 012, 23.07.2001 Anjozorobe (Antananarivo), R Ranonisoanavola (larger stream E from main mountain chain), 1200 m, (0/0/1) slide mounted, Ac 1355; MD 033 , 18.08.2001 Madiorano (Fianarantsoa), spring at the right border of the stream crossing the railroad at km 51.2 (MD 031), 650 m, (1/0/0) slide mounted, Ac 1358; MD 036 , 19.08.2001 Andrambovato (Fianarantsoa), spring stream 0.5 km SE from the 1.07 km-railway-tunnel, 900 m, (1/0/0) in liquid, Ac 1440; MD 037 , 20.08.2001 Andrambovato (Fianarantsoa), large cascade 3 km E from the village, 820 m, (1/0/0) slide mounted, Ac 1359; MD 042 , 21.08.2001 Ranomena (Fianarantsoa), riparian spring at the upper course of the stream NW from the 1.07 km-railway-tunnel (right affluent of MD 034), 1000 m, (5/1/0) in liquid, Ac 1441; MD 045 , 22.08.2001 Andrambovato (Fianarantsoa), riparian spring at stream E railway-tunnel 4 (about 1 km W of the village), 800 m, (13/15/0) in liquid, Ac 1442; (2/2/0) slide mounted, Ac 1360-1361 .

Diagnosis: Membranous parts of integument with densely-arranged, long papillae. Genital field ( Fig. 23 c ) with Ac-1 rather short, posteriorly narrowed (24–38 % genital flap L), Ac-2 rather various in size (31–53 % genital flap L); medial genital flap margins in posterior 2/3 subparallel, in males their posterior end rectangular. Leg claws with an only very slightly projecting basal blade ( Fig. 23 g , detail). Palp ( Fig. 23 f ) L/H ratio P-2, 1.6–1.9, P-3, 1.5–1.7, P-4, 3.9–4.5); P-4 mediodistal margin forming an obtuse angle at dorsodistal peg seta insertion.

Description: Integument papillae long and narrow, well visible also in areas covering underlying plates; these papillae fluted and therefore in vertical view appearing star-shaped; locally, especially on the posterior dorsum, a hexagonal background pattern of fine granulation is visible. Pores of idiosoma sclerites rather large (<10 per transect on dorsocentralia), inner trabecular structures prominent. Legs ( Fig. 23 g–h) relatively slender, claws with a slightly projecting, rounded basal blade.

Genital field embraced anteriorly by concave (in juvenile specimens straight or even convex) sclerotization made up by posteromedial margins of Cx-IV and medially extending sclerite arms, posteriorly by trabecular sclerites forming obtuse lateral angles. Genital flaps subtriangular, finely porose, with about 20 setae (longer and pennate at anterior and posterior edges, finer and hair-like along central medial margin). Ac-1 longish, in the membranous integument, embraced by concave sectors of anterior genital flaps; Ac-2/-3 often rather large, lens-shaped, inserted into the lateral respectively posterior genital flap margin; anterior to Ac-2 insertion, lateral genital flap margin concave, with variously developed, sometimes porose, fringe of secondary sclerotization.

Gnathosoma in lateral view with a smoothly S-shaped ventral margin, proximodorsal apodemes well developed. Chelicera with stout basal segment distoventrally extending into a long finely pointed extension flanking the long, needle-like claw, L/H ratio 5.9–7.5, basal segment/claw 0.9–1.1. Palp relatively stout, P-1 basally large, distally strongly narrowed, with one pennate dorsal seta; P-2 and -3 distally hardly expanding, P-2 bearing four fine dorsal and the two typical strong, pennate, distoventral setae, P-3 with three simple dorsal setae; P-4 long, with subparallel or slightly diverging ventral and dorsal margins, bearing 4 fine, hair-like setae, one dorsally in the proximal half, three flanking P-5-insertion, distal margin forming an obtuse angle at the insertion of the pointed distomedial peg seta; P-5 slender, with little curved claws.

Measurements: Male: Idiosoma L/W 825–925/500–665; coxal field L/W 450–540/460–540; Cx-I+II L/W 260– 300/150–170; Cx-III+IV L/W 215–250/160–210; genital field L/W 135–170/170–205; maximum diameter Ac-1, 45–65; Ac-2, 55–70; Ac-3, 40–48; ejaculatory complex L 170–200; gnathosoma L 190–200; chelicera L 340–353, L/H 5.9–6.4, basal segment/claw 0.94–1.04; palp total L 273–280; L, L/H ratio, relative L [% total L] palp segments: P-1, 45, 1.29–1.40, 16–17; P-2, 53–59, 1.75–1.88, 19–21; P-3, 45–46, 1.54–1.57, 17; P-4, 100, 4.00–4.21, 36–37; P-5, 30, 2.4, 11, P-2/-3 L 1.17–1.27, P-2/-4 L 0.53–0.59, P-3/-4 0.45–0.46. Leg segments L/H, L/H ratio: I-L-2, 85–93, 1.71–1.79; I-L-3, 78–93, 1.55–1.68; I-L-4, 125–143, 2.68–2.85; I-L-5, 133–155, 3.18–3.31; I-L-6, 128–133, 2.43–2.65; claw L 38–39; II-L-2, 100, 1.90; II-L-3, 90–95, 1.80–1.81; II-L-4, 168–175, 3.35–3.50; II-L-5, 170–178, 3.94–4.00; II-L-6, 155, 3.10; claw L 41–43; III-L-2, 88–90, 1.80–1.89; III-L-3, 78–83, 1.65–1.72; III-L-4, 150–155, 3.44–3.53; III-L-5, 153, 3.94–4.07; III-L-6, 145–153, 3.22–3.39; claw L 40–43; IV-L-2, 110, 2.10–2.20; IV-L-3, 108–115, 2.19–2.26; IV-L-4, 205–220, 4.40–4.56; IV-L-5, 193–250, 4.67–5.56; IV-L-6, 178–183, 3.48–3.55; claw L 44–48. Total L segments 2–6: I-L, 483–565; II-L, 683–703; III-L, 613–633; IV-L, 793–878.

Females: Idiosoma L/W 1050–1200/650–750; Cx-I+II L/W 280–330/170–200; Cx-III+IV L/W 240–290/210– 230; genital field L/W 170–185/195–220; maximum diameter Ac-1, 50–60, Ac-2, 65–90, Ac-3, 40–55; gnathosoma L 225–240; chelicera total L 485–498, basal segment/claw 1.31–1.34, L/H 7,4–7.8; Palp total L 314–328; L, L/H ratio, relative L [% total L] palp segments: P-1, 50–56, 1.32–1.43, 16–17; P-2, 63–68, 1.80–1.92, 20–22; P-3, 51–55, 1.52–1.63, 16–17; P-4, 113–118, 4.09–4.48, 35–37; P-5, 33–36, 2.89–2.90, 10–11. Leg segments L/H, L/H ratio: I- L-1, 55, 1.05; I-L-2, 93, 1.76; I-L-3, 90, 1.80; I-L-4, 143, 2.85; I-L-5, 143, 3.17; I-L-6, 140, 2.43; claw L 40. II-L-1, 48; 0.66; II-L-2, 135, 2.45; II-L-3, 133, 2.41; II-L-4, 195, 3.90; II-L-5, 190, 4.00; II-L-6, 163, 2.71; claw L 43. III-L- 1, 50–63, 0.69–0.83; III-L-2, 100–113, 1.80–1.90; III-L-3, 95, 1.65–1.81; III-L-4, 178, 3.23–3.74; III-L-5, 175–183, 3.68–3.84; III-L-6, 143–168, 2.59–2.91; claw L 45–50. IV-L-1, 120–123, 1.41–1.63; IV-L-2, 128–133, 2.12–2.32; IV-L-3, 128–129, 2.17–2.43; IV-L-4, 248–253, 4.30–4.59; IV-L-5, 230–248, 4.60–5.35; IV-L-6, 190–195, 3.25– 3.30; claw L 49–53. Total L segments 2–6: I-L, 608; II-L, 815; III-L, 690–735; IV-L, 933–945.

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

Remarks: The only previously known species of the genus, T. reticulata K. Viets, 1929 from Sumatra, was first described from a single female. Lundblad (1969) published the first description of the male and additional information on the variability of females, but without detailed measurements. Teratothyas reticulata (in parentheses) differs from T. proceripapillata in: (1) membranous integument areas with flattened papillae; (2) genital field with rounded Ac-1, relatively larger Ac-2 (maximum diameter nearly twice Ac-1 or -3) and convex medial genital flap margins not forming a posteromedial angle in males; (3) a stouter palp (for female and male calculated from Viets’ and Lundblad’s figures, respectively): L/H P-2, 1.4–1.6; P-3, 0.9–1.0 (relative L only 12–14 %). Concerning the shape of P-4, the female holotype of T. reticulata (L/H 4.2) lies within the variability range of T. proceripapillata (where no sexual dimorphism in palp shape is observed), while this segment is distinctly stouter in the male described by Lundblad (L/H 2.4). This difference suggests that the population studied by Lundblad might represent a species different from T. reticulata .

I attribute to T. proceripapillata also members of several populations collected from weakly seeping springs in the Fianarantsoa-Manakara area (MD 033, 036, 037, 042, 045). They all lay within the variability range of T. proceripapillata in nearly all measurements and proportions, but are not included into the type series due to some minor differences: Slide mounted specimens have a slightly stouter chelicera with a longer claw (L/H 5.0–5.6, basal segment/claw ratio 0.83–0.86) and have shorter integument papillae, in tangential view appearing truncated like merlons of a castle; the specimen from MD 037 also differs in more shortened acetabula (Ac-1, 24 %, Ac-2, 29 % genital flap L).

Habitat: Low and middle order streams.

Distribution: Madagascar, endemic, in relict forest areas of the centre and on the northeastern slopes.

Figures

FIGURE 23. Family Teratothyadidae, Teratothyas (s. str.) proceripapillata (MD 011–016) (originals, D. Cook). a.–c. female; a. idiosoma, dorsal view; b. idiosoma, ventral view; c. genital field; d. male genital field; e. male gnathosoma and palp; f. female palp; g. male I-L (detail: claw); h. male IV-L (detail: seta).