Nilotonia (Dartia) lii, Yi, Tianci, Jin, Daochao & Guo, Jianjun, 2009

Yi, Tianci, Jin, Daochao & Guo, Jianjun, 2009, Description of a new species of Anisitsiellidae Koenike, 1910 (Acari, Hydrachnidia), the first record of the family from China, Zootaxa 2158, pp. 50-56 : 51-55

Nilotonia (Dartia) lii sp. nov.

( Figs. 1–20 )

Type series: Holotype: male, Luyashan National Nature Reserve (111°50"– 112°05"E, 38°35"– 38°45"N), Shanxi province, China, 17 August, 2002, leg. Guo Jianjun. Paratype: one female, the same data as the holotype.

Diagnosis: Glandularia with very long setae and large glandular sclerites, V3 fused with posterior margin of CxIV in male, coxae extended latero-dorsally in female, genital field elongated, the first acetabulum located at anterior end of genital flaps, the second and the third close to each other and at posterior end of the flaps, but not fused.

Description: Male Body soft, 671 in length, 579 in width, cuticula with strong dense lineations, dorsal sclerites papillate; surface of coxae, legs and palps with circular patch composed of fine papilla ( Fig. 13 ); dorsum ( Fig. 1 ) with a pair of anterior platelets fused with O2 and a single posterior plate (119 in length, 128 in width), posteriorly between D3; A1 seta long and serrated, O1 between and slightly anterior to A1, A2 between the lateral eyes, O2 posterior to D1, positions of 16 pairs of glandularia showed in lateral view ( Fig. 3 ); infracapitular bay V-shaped ( Fig. 2 ), CxI separated but medially close, length of CxI medial margin 115; E2 fused with anterior margin of EpIII, suture line between glandular sclerite of E2 and CxIII missing; medial margin of PCG round and without secondary sclerotization, distance between medial margin of PCG 65; suture lines between EpIII and CxIV incomplete; E4 reduced, on anterior margin of CxIII; genital field elongated, 181 in length, 125 in width, with three pairs of acetabula; acetabula small, second and third acetabulum close to each other but not fused, far from first one which located at anterior end of genital flap; V3 fused with posterior margin of CxIV; dorsal capitular apodeme lath-shaped, ventral capitular apodeme nail-shaped; chelicera ( Fig. 5 ) 265 in length, chelicera claw 75 in length; ventral surface of P-II denticulate with a peg-like seta 26 in length; P-IV with well developed ventral tubercles; two lateral terminal seta of P-IV as long as P-V and well separated; dorsal length of P-I to P-V: 21, 108, 63, 118, 25. Shape and chaetotaxy of legs showed in Fig. 12 to Fig. 16 , dorsal lengths of leg segments in Table 1. The fifth segment of the second leg is broad, one strong setae at widest part and another strong one anteriorly on base of broad part, and a fine seta in between the two strong setae; the sixth segment of the fourth legs is anisomerous, that of the right leg ( Fig. 15 ) with four short peg-like setae in a row and a long sub-terminal seta while left leg ( Fig. 16 ) with two pinnate setae and a long sub-terminal seta, the tip of the sixth segment of the fourth legs with two short and strong setae; claws with a slender dorsal clawlet and a few ventral clawlets in a row.

Female Body, similar to male, 610 in length, 420 in width; dorsal view ( Fig. 8 ) similar to male, but L1 shifted to dorsum; single posterior dorsal plate 131 in length, 119 in width; ventral view ( Fig. 9 ) similar to male, but V3 separated from CxIV; insertions of fourth legs protruding; coxae well developed and extended to the latero-dorsal ( Fig.8 ); medial margin of CxI 113 in length; genital field 223 in length, 148 in width; palp ( Fig. 10 ) and chelicera ( Fig. 11 ) similar to male; shape and chaetotaxy of legs as shown in Fig. 17 to Fig. 20 , dorsal lengths of leg measurements in Table 1.

Etymology: Named after professor Li Zizhong, Institute of Entomology, Guizhou University, for his encouragement.

Remark: The relationship between Anisitsiellidae and Limnesiidae has always been of great interest to science ( Cook, 1963; Tuzovski, 1987; Smith & Cook, 1994; Harvey, 1998; Goldschmidt, 2004a, 2004c; Panesar, 2004; Davids et al., 2006). However, there is no consensus on the taxonomic position of Anisitsiellidae , therefore, the family position in the traditional systematics ( Cook, 1974) is still accepted in this study.

The subgenus Dartia is commonly defined by the sexual dimorphism of the fifth segment of the second leg. Panesar (2004) modified the characters of the subgenus by “the modifications in the genital field, gap between first and second acetabulum larger or about as long as first acetabulum; basal sclerites of acetabula always enlarged and typically the posterior two pairs on each side fused to each other…”. However, in Nilotonia (Dartia) lii sp. nov. and Nilotonia (Dartia) pinnata Guo, Jin & Asadi 2005 from Iran the second acetabulum is not fused with third one, and the basal sclerites of them are not enlarged. In Nilotonia (Dartia) lii sp. nov., the second acetabulum and the third one are very close to each other. Therefore, the definition of the subgenus Dartia given by Panesar (2004), “basal sclerites of acetabula always enlarged and typically the posterior two pairs on each side fused to each other.” should be revised when more material is available.

Up to date, five species - N. (D.) borneri , N. (D.) harrisi , N. (D.) erzurumiensis , N. (D.) vietsi , and N. (D.) pinnata - with this sexual dimorphism have been reported from Europe and Asia. Male of Nilotonia (Dartia) lii sp. nov. with sexual dimorphism is most close to N. (D.) vietsi Bader & Sepasgozarian 1980 ( Bader & Sepasgozarian 1980; Bader 1984; Özkan & Kücükönder 1993), which shares the following characters: two peg-like setae on the broad part of the fifth segment of the second leg, V3 very close to posterior margin of CxIV, a very elongated genital field and larger gap between the first acetabulum and the third. However, in the new species, glandularia with very long setae (43–144 in length), while in Nilotonia (Dartia) vietsi , the longest setae are only 30μm ( Bader and Sepasgozarian 1980, p163); V3 is fused to posterior margin of CxIV in the male, and the coxae are well developed and extended latero-dorsally in the female.

segment I II III IV

male female male female male female male female 1 39 46 58 61 68 75 105 75 2 47 52 68 71 81 75 71 77 3 59 77 75 80 86 91 97 101 4 96 95 103 122 154 167 149 165 5 113 121 124 142 168 160 186 197 6 95 90 101 105 124 130 166 191

Figures

FIGURES 1 – 7. Nilotonia (Dartia) lii sp. nov. male. 1 — dorsal view, 2 — ventral view (right anterior coxae broken), 3 — lateral view, 4 — genital field, 5 — lateral view of chelicera, 6 — lateral view of capitulum, 7 — lateral view of palp. Scale bars = 100 μm.

FIGURES 8 – 11. Nilotonia (Dartia) lii sp. nov. female. 8 — dorsal view, 9 — ventral view; 10 — lateral view of palp; 11 — lateral view of chelicera. Scale bars = 100 μm.

FIGURES 12 – 20. Nilotonia (Dartia) lii sp. nov. legs of male (12 – 16) and female (17 – 20). 12 — I-L- 2 – 6 (first segment missing), 13 — II-L, 14 — III-L- 2 – 6 (first segment missing), 15 — IV-L- 2 – 6 (first segment missing) (right), 16 — IV-L- 6 (left), 17 — I-L, 18 – II-L, 19 — III-L, 20 — IV-L. Scale bar = 100 μm.