Limnesia (Limneisa) diploseta, Yi, Tianci & Jin, Daochao, 2009

Yi, Tianci & Jin, Daochao, 2009, Water mites of the genus Limnesia Koch, 1836 (Acari: Hydrachnidia, Limnesiidae) from China, with description of four new species, Zootaxa 2234, pp. 21-38 : 22-24

Limnesia (Limneisa) diploseta sp. nov.

Figure 1 , A–L

Type series: Holotype: Male, Hulan River, Yichun City, Heilongjiang Province, 19 August 1996, leg. Jin Daochao. Paratype: Two females, the same data as the holotype. All were dissected and slide-mounted.

Diagnosis Actaubula oval, small (major axis 22–24 in length, minor axis 13–17 in length) and homomorphic; outer side of genital plates of female slightly convex; IV-L-6 with 2–3 long distal setae.

Description Male Body soft and smooth, 693 in length, 551 in width; dorsum with a pair of anterior small platelet fused with O1; A1 located on ventral anterior end of body; lateral eyes separated, O1 posterior to anterior-lateral eyes; A2 slightly anterior to posterior-lateral eyes; O2 anterior to D1; coxae occupying almost half the ventral surface; infracapitular bay V-shaped, longer than median margins of CxI; CxI separated but close to each other; ACG and PCG separated; medial margins of CxIII round with small secondary sclerotization; distance between CxIII median angles (including the secondary sclerotization) 73; sucture line between CxIII and CxIV incomplete, ending at E4; V3 lateral to V1; V1, V3 and the second acetabulum at the same level; genital plate 163 in length and 160 in width; three pairs of genital acetabula, the second acetabulum near to the third but far away from the first; a number of setae situated along the margin of the genital plate; chelicera as shown in Figure 1 -H, 245 in length, chelicera claw 58 in length; proportions and chaetotaxy of palp as shown in Figure 1 -F; mid-ventral side of P-II smooth with a peg-like seta (14 in length); ventral side of P-IV with two homomorphic hair-like setae and one fine seta; dorsal lengths of P-I to P-V: 25, 123, 85, 151, 50; I-L-5 with two ventral long distal setae; IV-L-6 with two strong setae in a row and two swimming hairs in right ( Figure 1 -I), three long swimming hairs in left ( Figure 1 –K); claw with one slender dorsal clawlet and one ventral thick clawlet; dorsal lengths of I-L-3 to 6: 85, 96, 95, 102; dorsal lengths of IV- L-3 to 6: 113, 178, 223, 198; III-L-4 with 2, III-L-5 with 4, IV-L-4 with 3 and IV-L-5 with 5 swimming hairs.

Female Body soft and smooth, 741 (621) in length, 501 (490) in width; the shape of dorsum and coxae are similar to male; genital plates (including pregenital sclerite) 188 (198) in length and 125 (158) in width; three pairs of round genital acetabula, distance between the first and the second acetabulum about three times of diameter of the first acetabulum; chelicera 260 (278) in length, chelicera claw 61 (73) in length; peg-like seta on ventral side of P-II 15 (14) in length; dorsal lengths of P-I to P-V: 21 (24), 116 (106), 74 (101), 178 (192), 51 (49); dorsal lengths of I-L-3 to 6: 84 (63), 100 (95), 128 (119), 101 (98); dorsal lengths of IV-L-3 to 6: 109 (127), 179 (195), 206 (223), 211 (231); anterior swimming hairs on IV-L 125 (120) in length, posterior one 176 (150) in length; III-L-4 with 1 (1), III-L-5 with 2 (3), IV-L-4 with 2 (2) and IV-L-5 with 3 (4) swimming hairs.

Remarks The new species closely resemble Limnesia connata Koenike, 1895 from Eurasia and Limnesia tundrosum Tuzovskij, 1997 from Russia. However, outer side of genital plates of female deeply concave in L. connata emarginare while slightly concave in new species. Genital field of male enlongated while in new species the ratio of genital length to width is about 1. The following morphological characteristics distinguish the new species from Limnesia tundrosum . Acetabula are oval (major axis 22–24 in length, minor axis 13–17 in length) and homomorphic, while heteromorphic in Limnesia tundrosum , the third acetabulum is smaller than the others. Seven dorsal setae are on P-II, only four dorsal setae in Limnesia tundrosum . A pair of small dorsal plate fused with O2, while a small pair of anterior dorsal plate and a pair of moderate posterior dorsal plate present in Limnesia tundrosum .

Etymology Named after two long setae on IV-L-6.

Figures

FIGURE 1. Limnesia diploseta sp. nov. A—idiosoma, ventral view, male, B—idiosoma, dorsal view, male, Cidiosoma, ventral view, female, D—genital field, female, E—genital field, male, F—palp, lateral view, male, Ginfracapitular, lateral view, male, H—chelicera, lateral view, male, I & K—IV-L- 5, 6, male (right & left), J—I-L- 5, 6, male, L—IV-L- 5, 6, female. Bars = 100 Μm.