Sperchon (Sperchon) sounkyo Imamura, 1954

Zhang, Xu & Jin, Dao-Chao, 2011, New records of water mites of the family Sperchontidae Thor, 1900 from China (Acari, Hydrachnidia), with descriptions of two new species, ZooKeys 158, pp. 89-109 : 96-97

Sperchon (Sperchon) sounkyo Imamura, 1954 Figures 2231

Material examined.

25 males and 36 females, Xinjiang Uygur Autonomous Region, Altay City, Kanas Lake (48°48'59"N, 87°02'01"E), 14 August 1997, coll. Dao-Chao Jin; 2 males, Shanxi Province, Taibaishan Mountain National Forest Park, Honghuaping area scene, an unnamed stream (34°07'16"N, 107°53'46"E), 02 September 1997, coll. Dao-Chao Jin; 3 females, Hebei Province, Wulingshan National Nature Reserve, an unnamed stream (40°37'23"N, 117°29'51"E), 03 April 2002, coll. Jian-Jun Guo; 2 males and 1 female, Guizhou Province, Xishui National Natrue Reserve, an unnamed stream (28°28'19"N, 106°05'41"E), 02 Jun 2002, coll. Jian-Jun Guo; 10 males and 8 females, Guizhou Province, Kuankuoshui National Natrue Reserve, an unnamed stream (28°14'25"N, 107°11'59"E), 22 May 2004, coll. Zhen-Zao Tian and Ai-Ping Cui; 11males and 9 females, Guizhou Province, Leigongshan National Nature Reserve, an unnamed stream (26°21'24"N, 104°34'40"E), 21 May 2005, coll. Xu Zhang.

Description.

Male (n = 4):Idiosoma oval in outline, 561 (523-635) in length, 396 (374-418) in width. Cuticle yellow-brown, covered with scale-shaped papillae (Fig. 24). A1 short and plumose, setae of other glandularia smooth and relatively long. Cuticle without dorsalia and ventralia except the platelets surrounding glandularia and O2 (Fig. 22, Fig. 23). Coxae in four groups, surface of coxae reticulated. ACG 157 (148-166) in length, apodeme developed. E2 laterally between ACG and PCG. PCG 167 (160-174) in length. E4 on the median and near to inner margin of CxIII. Distance between anterior end of ACG and posterior end of PCG 308 (283-317). Genital field between PCG with a small and rounded platelet in front. Genital valves not covering the genital acetabula, 113 (108-121) in length, 109 (101-114) in width. Pre- and postgenital sclerites visible though not developed. Three pairs of genital acetabula, the first pair of genital acetabula more or less rectangular, the second pair somewhat triangular, and the third pair rounded and larger than the anterior two. V1 on median size sclerites and without accompanying glandularia. Excretory pore without sclerotized ring, and anterior to the line of V2 glands.

Infracapitulum with a short rostrum, length 193 (185-203). Chelicera total length 204 (194-219), basal segment length 151 (146-160), claw length 53 (48-59), basal segment/claw length ratio 2.8 (2.7-3.0). Dorsal lengths of the palpal segments: P-I, 21 (19-23); P-II, 94 (85-102); P-III, 102 (94-108); P-IV, 97 (92-111); P-V, 24 (22-27). P-I short and without seta. P-II with a long ventro-distal projection, one thin and long seta near to the base of the projection. Four setae on the dorsal and lateral side of the P-II, one of them plumose. The ventral side of P-III nearly straight and without seta, six short smooth setae on the lateral and dorsal side. P-IV with two small peg-like ventral setae and three thin setae, the proximal peg-like seta is larger than the distal one. The dorsal of P-IV with three thin setae, two of them located distally. Dorsal lengths of the first leg: I-L-1, 44 (39-50); I-L-2, 63 (55-71); I-L-3, 68 (59-76); I-L-4, 119 (112-138); I-L-5, 109 (102-123); I-L-6, 105 (97-114). Dorsal lengths of the fourth leg: IV-L-1, 61 (57 - 65); IV-L-2, 85 (76-95); IV-L-3, 103 (92-116); IV-L-4, 195 (183-210); IV-L-5, 204 (191-218); IV-L-6, 162 (149-178). Third to fifth segments of leg I-IV with rather short smooth setae in longitudinal rows. Ambulacrum with two claws and each claw with protruded claw-blade and two clawets, a long dorsal and a shorter ventral one (Fig. 28).

Female (n = 3):Similar to male except for the morphology of genital field and the size of idiosoma (Fig. 30, Fig. 31). Idiosoma 910 (768-944) in length, 570 (493-648) in width. ACG 182 (170-190) in length, PCG 215 (204-221) in length. Distance between anterior end of ACG and posterior end of PCG 397 (381-405). Genital field 174 (164-181) in length, 154 (144-162) in width. Pre- and postgenital sclerites more developed than in the male. Infracapitulum length 229 (213-238). Chelicera total length 270 (246-279), basal segment length 200 (183-205), claw length 70 (63-74), basal segment/claw length ratio 2.9 (2.7-2.9). Dorsal lengths of the palpal segments: P-I, 23 (20-25); P-II, 123 (118-130); P-III, 149 (142-156); P-IV, 113 (107-122); P-V, 29 (26-33). Dorsal lengths of leg I: I-L-1, 43 (37-49); I-L-2, 65 (60-74); I-L-3, 85 (79-97); I-L-4, 147 (136-154); I-L-5, 134 (125-147); I-L-6, 112 (106-120). Dorsal lengths of leg IV: IV-L-1, 75 (70-82); IV-L-2, 111 (103-119); IV-L-3, 118 (112-127); IV-L-4, 242 (221-263); IV-L-5, 223 (208-237); IV-L-6, 187 (178-196).

Remarks.

Sperchon sounkyo Imamura, 1954, was firstly described from Japan based on a single female ( Imamura 1954), and never recorded since the first description.

Although the original descriptions and illustrations of Sperchon sounkyo were lacking of some specific features, such as shape of A1 (Fig. 22, Fig. 30) and leg claws (Fig. 28), most characters of our specimens (e.g., shape of cuticle and palp, E4 on CxIII, and excretory pore without sclerotized ring) are in accordance with this species. So we attribute our specimens to Sperchon sounkyo Imamura, 1954. Some differences found in the body size and the number of the setae on the palpal between the Chinese specimens and Japanese specimens should be regarded as the variety between the different populations.

It is the first report from China and the first description of the male of Sperchon sounkyo . This species seems to be a widely distributed species in China.

Distribution.

China (present study); Japan ( Imamura 1954).