Zelandatonia orion Cook, 1992

SmitK, Harry & PešićK, Vladimir, 2024, New records of rare water mites from New Zealand, with the description of a new genus (Acari: Hydrachnidia), Acarologia 64 (2), pp. 602-611 : 606

Zelandatonia orion Cook, 1992

Figure 2

Material examined — South Island. 2/1/0, Camp Creek, interstitial, Lake Kaniere Scenic Reserve, 42°50.313′ S, 171°09.910′ E, 156 m asl, 13.ii.2023, one male, dissected and slide mounted ( RMNH), one female partly dissected (palp, I-leg and IV-leg from one side dissected) and slide mounted ( RMNH).

Remarks — This species was described by a single female collected from a driven well near Nelson, South Island ( Cook 1992). Thus far, the male was unknown, and therefore a description is given below. Our specimens generally matches the original description except in the dorsum with three pairs of sclerites, instead of the two pairs in the female, postocularia and the most posterior pair, as illustrated by Cook (1992).

Description — Male — Integument soft and lineated, 894 long and 644 wide; dorsum with three pairs of sclerites, anterior pair with postocularia ( Figure 2A ). Coxal groups close together but not fused, anterior coxal group much smaller than posterior coxal group; gnathosomal bay relatively shallow and V-shaped, 125 long; Cx-III/IV suture line incomplete; glandularia of Cx-III near anterior margin; Cx-IV expanded, enclosing genital field ( Figure 2B ); a pair of small setae fused with posterior margin of Cx-IV. Genital field with three pairs of acetabula, 178 long and 128 wide, length of Ac–1-3: 50, 53, 39. Ejaculatory complex 222 long. Excretory pore on a small rounded sclerite.

Palp as illustrated in Figures 2 C-D: dorsal length/height (ratio given in parentheses): P1, 25/44 (0.57); P2, 106/97 (1.1); P3, 59/78 (0.76); P4, 100/41 (2.46); P5, 31/16 (2.0); palpal segments, especially P2 and P3 stocky; P2 ventral seta distanced from the margin of the segment; P4 without ventral tubercles. Gnathosoma 134 long; chelicera ( Figure 2E ) 172 long. Dorsal lengths of I-leg: 69, 88, 109, 166, 175, 181; dorsal lengths of IV-leg: 116, 114, 134,

206, 228, 206; III-leg-4 with one two swimming seta; III-leg-5 with two short swimming setae; IV-leg-4 with two swimming setae; IV-leg-5 with five swimming setae as illustrated in Figure 2G .

Distribution — Previously known from the type locality on South Island ( Cook 1992).

Figures

Figure 2 Zelandatonia orionCook, 1992, male, Camp Creek. A – idiosoma, dorsal view (inset: glandularium, 2x enlarged); B – idiosoma, ventral view; C-D – palp; E – chelicera; F – I-leg-4-6; G – IV-leg-5 and -6; H – terminal part of IV-leg-6. Scale bars = 100 μm.