Limnochares connexa Tuzovskij & Gerecke, 2009

Gerecke, Reinhard, 2020, The early derivative water mites (Acari: Hydrachnidia, superfamilies Eylaoidea, Hydrachnoidea and Hydryphantoidea) of Madagascar, Zootaxa 4727 (1), pp. 1-77 : 9-11

Limnochares connexa Tuzovskij & Gerecke, 2009

Figs 4 – 5

New records: MD 188, Joffreville (M. d’Ambre, Antsiranana), Maison Rousettes, river with small cascade and pool near house of guardian, 1044 m, S 12°31’37.0’’, E 049°10’19.9’’, Gerecke 28.03.2011, (4/0/0) slide mounted, Ac 1321 – 1324; (8/1/0) in liquid, Ac 1438; MD 234, Ranomena (Fianarantsoa), spring area of the stream NW from the 1.07 km-railway-tunnel (same site as MD 043), right affluent of MD 034), 1017 m, S 21°29’45.9’’, E 047°24’07.5’’, 26.04.2011, (0/3/0) slide mounted, Ac 1325 – 1327, 4 adults, 1 dn in liquid, Ac 1437.

Material examined: Limnochares connexa , SMF; Holotype ♀, MD 041, paratypes ♂, MD 042, ♀ MD 035 (Tuzovskij & Gerecke 2009).

Remarks: Several contradictions during comparison with the original description induced me to revise the type material and give new data based on the two populations collected in 2011. Possibly as an effect of seasonality, specimens collected in the rainy season of 2011 differ from those of the type series (from the dry season 2001) in distinctly major dimensions and the presence of an additional pair of dorsal sclerites ( Fig. 5 e ). To assess this phenomenon, the potential in limnocharids for additional moults ( Böttger 1972) and corresponding changes in morphology at the adult stage must be kept in mind. Important details testify for the conspecificity of all Limnochares material from this study site: In addition to the diagnostic features given in the original description–a narrow fusion of Cx-III+IV ( Figs 4 a , 5 f ) and club-shaped setae on the frontal sclerite ( Fig. 4 b )–they have two previously overlooked features: (1) the rather inflated P-4 bears a very fine seta which is distally enlarged to form a finely serrate apical surface ( Fig. 4 c ); (2) the setae in the male genital field are furcate ( Fig. 5 f ).

Measurements (MD 234): Male: Idiosoma L/W 1800/1000; frontal shield 360/100; anterior dorsal plate 350/45; Cx-I+II, 385/295, mL 275; Cx-III+IV, 665/245; setae numbers: Cx-I, 15; Cx-II, 11; Cx-III, 10; Cx-IV, 8; genital field with 50 pairs of acetabula and 60 pairs of setae; genital skeleton L 200. Leg segments, L/H (ratio): I-L-1, 130/140 (0.93); I-L-2, 170/115 (1.48); I-L-3, 165/95 (1.74); I-L-4, 170/85 (2.00); I-L-5, 270/80 (3.38); I-L-6, 210/80 (2.63), claw 85; II-L-1, 85/145 (0.59); II-L-2, 205/105 (1.95); II-L-3, 195/85 (2.29); II-L-4, 200/80 (2.50); II-L-5, 250/80 (3.13); II-L-6, 240/75 (3.20), claw 75; III-L-1, 75/138 (0.55); III-L-2, 200/80 (2.50); III-L-3, 195/75 (2.60); III-L-4, 215/80 (2.69); III-L-5, 265/75 (3.53); III-L-6 not measured; IV-L-1, 100/145 (0,69); IV-L-2, 250/85 (2.94); IV-L-3, 250/80 (3.13); IV-L-4, 285/75 (3.80); IV-L-5, 350/75 (4.67); IV-L-6 not measured. Mouthparts: Gnathosoma basal L 240, total L 490; chelicera L 555, L/H 9.3, basal segment/claw ratio 4.0; palp total L 315; L/H (ratio) P-1, 55/35 (1.57); P-2, 95/45 (2.11); P-3, 58/43 (1.35); P-4, 78/45 (1.72); P-5, 30/10 (3.00); L ratio P-2/P-4, 1.23, P-4/P-5, 2.58.

Female: Idiosoma L/W 2500/1500; frontal shield 415/115; anterior dorsal plate 360-375/50-75 Cx-I+II, 400- 430/310-325, mL 295-310; Cx-III+IV, 760-840/265-320; setae numbers: Cx-I, 16-18; Cx-II, 13-14; Cx-III, 14-15; Cx-IV, 8-9; genital field with 50-70 pairs of acetabula and 25 pairs of setae. Egg maximum diameter 450 (n=5). Mouthparts: Gnathosoma basal L 315, total L 550; chelicera L 590-605, basal segment/claw ratio 10.7; palp total L 409; L/H (ratio) P-1, 73/49 (1.47); P-2, 116/58 (2.00); P-3, 73/55 (1.32); P-4, 104/55 (1.89); P-5, 44/16 (2.73); L ratio P-2/P-4, 1.11, P-4/P-5, 2.40.

Figures

FIGURE 4. Family Limnocharidae, Limnochares connexa female. a. coxae and genital field, partial view; b. frontal shield; c. palp; d. gnathosoma.

FIGURE 5. Family Limnocharidae, Limnochares connexa male. a.–d. I-IV-L-3–5, claw; e. dorsal sclerites; f. genital field and left Cx-III+IV.