Orientilimnesia sinica Yi & Jin

Yi, Tianci, Jin, Daochao, Guo, Jianjun & Zhang, Xu, 2009, Descriptions of a new genus Orientilimnesia (Hydrachnidia: Limnesiidae Thor, 1900) with a new species from China, Zootaxa 2140, pp. 27-32 : 29-31

Orientilimnesia sinica Yi & Jin sp. nov.

Diagnosis: As for the genus.

Type series: Holotype: male, Fujian Province, Wuyishan National Nature Reserve (117°27"– 117°51"E, 27°35"– 27°54"N), stream, October 22, 2005, leg. Guo Jianjun. Paratypes: 8 males, 3 females, same locality as holotype, October 22, 2002 (2 males, 1 female) and October 20, 2005 (6 males, 2 females), leg. Guo Jianjun; 21 males, 18 females (8 males, 3 females slide mounted, 13 males, 15 females unmounted), Guizhou Province, Dashahe Nature Reserve (107º21´35"– 107º47´37" E, 29º00´02"– 29º13´17" N), paddy field, May 23, 2004, leg. Tian Zhenzao and Cui Aiping.

FIGURES 1–16. Orientilimnesia sinica sp. nov. (male: 1–7, 10, 11, 14–16, female: 5, 8, 9, 12). 1, 2, idiosoma, dorsal view; 3, idiosoma, ventral view; 4, idiosoma, lateral view; 6–9, genital field; 10, chelicera; 11–13, palp, lateral view; 14, lateral view of infracapitulum; 15, I-L-5-6; 16, IV-L-5-6; Scale bars = 100μm.

Description: Male (n = 16) Body soft and papillate, L 691 (519–781, 648), W 542 (421–600, 515); dorsum with a pair of small platelets (Fig. 2), in some specimens this platelets not present (Fig. 1); setae of A1 are thicker than that of all other glandularia; lateral eyes separated, anterior-lateral eyes spherical, posteriorlateral ones peanut-like shaped; O1 slightly posterior to anterior-lateral eyes, A2 anterior to posterior-lateral eyes, O2 anterior to D1, D4 located at caudal end of body; infracapitular bay V shaped, longer than medial margins of EpI; EpI separated but close to each other; posterior apodemes of AEG long, reach to EpIII; AEG and PEG separated; E4 located on EpIII; distance between EpIII median angles 92; Genital field L 190 (198–245, 221) and W 220 (210–255, 236); three elongated acetabula with thickened and sinuate edge; numerous fine seta on the genital flaps; the first acetabulum approximately at a right angle with the second and the third acetabulum which almost equal in length and parallel each other; the second acetabulum posterolateral to and somewhat underneath the third one; gonopore, L 120, slightly in the front of genital field. Figs. 1–4 show the position of glandularia; excretory pore located between V2; chelicera L 273, claw L 82 in length; P-II ventral margins slightly concave with a pronounced peg-like seta (L 16) insertion (Fig. 11), in some specimen P-II ventral margin straight (Fig. 13); two hair like setae on ventral P-IV; dorsal L of P-I to P- V: 21, 106, 76, 142, 38; dorsal L of I-L-3 to 6: 70, 85, 110, 45; dorsal L of IV-L-3 to 6: 126, 181, 197, 154; subterminal seta of IV-L-6 L 107; claw with a slender dorsal clawlet and a ventral thick clawlet; III-L-4 with 2, III-L-5 with 6 and IV-L-5 with 5 swimming hairs.

Female (n = 6) Body soft and papillate, L 832 (670–969, 840), W 653 (411–789, 615); shape of epimerae are similar to male; distance between EpIII median angles 70; genital field L 210 (190–215, 208), W 157 (160–210, 188), numerous fine setae on the genital flaps; three elongated acetabula on each genital flap, with thickened and sinuate edge; the first acetabulum slightly curved, second and the third acetabulum parallel, and the second one shorter and posterior to the third one which almost half of genital flaps in length; chelicera 336 in length, claw 98 in length; the characters of palp similar to male; ventral peg-like seta of P-II 24 in length; dorsal lengths of P-I to P-V: 17, 134, 75, 43, 51; dorsal lengths of I-L-3 to 6: 89, 116, 137, 103; dorsal lengths of IV-L-3 to 6: 146, 219, 235, 223, subterminal seta of IV-L-6 100 in length; III-L-4 with 3, III-L-5 with 7, IV- L-4 with 4 and IV-L-5 with 5 swimming hairs.

Etymology: Named after China.

Remarks: The arrangement of elongated acetabula is the unique character of the new species and genus. The lengths of acetabula among different specimens are variable (see Table 1 and 2, Figs. 6–9). The length of the gonopore varies from less than half of the genital plate to more than half of the genital plate (see Table 1 and 2). The specimens of the Fujian population show some small differences from the Guizhou population in the palp and dorsum. In the Fujian population, the ventral margin of P-II is slightly concave with a pronounced peg-like seta insertion (Figs. 11, 12) and the dorsum without small platelets (Fig. 2) while in the Guizhou population, the ventral margin of P-II is straight (Fig. 13) and the dorsum bears a pair of small platelets (Fig. 1).