Sinhaladwipabates scutatus, Smit, 2018

Smit, Harry, 2018, A second species of the water mite genus Sinhaladwipabates Gledhill & Wiles, 1997 from Thailand (Acari: Hydrachnidia: Hygrobatidae), Ecologica Montenegrina 18, pp. 99-101 : 100-101

Sinhaladwipabates scutatus n. sp.

Type material. Holotype female, Huai Chan Waterfall , Ubon Ratchathani Province, Thailand, 14° 31.403 N 104° 22.120 E, alt. 222 m a.s.l., 11-xi-2017, leg. H. Smit ( RMNH).

Description. Female: Idiosoma dorsally 384 long and 308 wide, ventrally 354 long. Dorsum with a large dorsal shield, 356 long and 270 wide, with four pairs of glandularia, the preocularia and the postocularia. Dorsal furrow with three pairs of small glandularia platelets. Eyes large. Gnathosoma separated from Cx-I, with a large upturned rostrum; dorsal of the rostrum a long seta; gnathosoma without an anchoral process. Venter with large ventral shield incorporating the coxae but the genital field is lying in a half-circular area of membranous integument. All suture lines of coxae incomplete. Cxgl-2 located near posterior suture line between Cx-II and Cx-III, Cxgl-4 located near suture line between Cx-III and Cx-IV. Genital field with four pairs of unequal acetabula, 114 wide; genital plate 32 wide. Pregenital sclerite fused with ventral shield. Excretory pore posterior to ventral shield. Lengths of P1-5: 16, 30, 26, 42, 26. P4 with two stiff ventral setae and a very large stout seta. Length of I-leg-4-6: 40, 44, 58 (till tip of segment). First leg much stockier than the three other legs. I-leg-5 with two short, stout distoventral setae and one moderately long hair-like setae. Length of IV-leg-4-6: 70, 78, 64. II-, III- and IV-leg-5 with two swimming setae.

Male: Unknown.

Etymology. Named for the presence of a large dorsal plate.

Remarks. The new species differs from Sinhaladwipabates kumariae Gledhill & Viets, 1997 in the following characters (in parentheses S. kumariae ): Dorsal shield with four pairs of glandularia, the preocularia and the postocularia (only two pairs of glandularia), gnathosoma with one long seta dorsal of rostrum (two setae), P5 stocky (P5 slender) and I-leg-5 anteroventrally with two short setae (two long setae). The anteroventral hair-like seta of I-leg-5 of the new species is not found in S. kumariae , but this seta is easily lost during mounting.

The finding of a new species of Sinhaladwipabates requires an emendation of the diagnosis of the genus: Characters of the genus as described by Gledhill & Wiles (1997). Dorsal shield with 2-4 pairs of glandularia, with or without the preocularia and the postocularia. Gnathosoma with 1-2 long setae dorsally of rostrum.