Tryssaturus longwood, K & PešićK, 2024

K, Harry Smit & PešićK, Vladimir, 2024, New records of notoaturine water mites from New Zealand, with the description of five new species (Acari: Hydrachnidia: Notoaturinae), Acarologia 64 (2), pp. 499-524 : 515-518

Tryssaturus longwood n. sp.

Zoobank: 9732C558-D149-44E1-94CC-409D89ECFE1B

Figures 9 , 10 , 14I

Material examined — Holotype male, small mossy stream crossing road to Bald Hill , Longwood Forest, South Island, 46°10.873′ S, 167°49.523′ E, alt. 671 m asl., 31 Jan. 2023, dissected and slide mounted ( NMNZ) . Paratype: 1/0/0, same data as the holotype ; 2/0/0, unnamed stream crossing road to Bald Hill, South Island, 46°11.355′ S, 167°49.630′ E, alt.

561 m asl., 31 Jan. 2023 ( RMNH); 0/1/0, Caution Creek, Fox Glacier Track, South Island, 43°29.584′ S, 170°01.690′ E, alt. 277 m asl., 12 Febr. 2023, dissected and slide mounted ( RMNH).

Diagnosis — Unpaired anteromedial dorsal plate distinctly wider than long; male dorsal shield without reticulate ornamentation; IV-leg-2 with a distal projection and 3-4 thickened setae on medial surface.

Description — Male — Idiosoma dorsally 534 long and 377 wide, ventrally 553 long. Eye pigment present. Dorsal shield ( Figure 9A ) typical for the genus Tryssaturus , 441 long and

359 wide, without reticulate ornamentation; unpaired anteromedial plate wider than long, 191 long, and 256 wide; unpaired posteromedial plate longer than anterodorsal plate, 250 long and 275 wide; anterolateral platelet 178 long, posterolateral platelet 148 long. Coxae confined to anterior half of idiosoma; Cx-I projecting, with tips more or less rounded, gnathosomal bay 120 long; glandularia Cxgl-4 well distanced from suture line Cx-III/IV, projections associated with insertions of fourth legs bluntly pointed and with a few long setae on lateral margins; posterior margins of Cx-IV placed at right angles to midline. Genital field with numerous acetabula in two or three rows along posterior margin, gonopore oval and subterminal, 44 long and 38 wide.

Palp as illustrated in Figure 9C ; dorsal length/height (in parentheses length/height ratio) of palpal segments: P1, 31/14 (2.2); P2, 62/37 (1.7); P3, 34/28 (1.2); P4, 77/27 (2.8); P5, 38/13

(3.0); P4 without medial ridge, ventral setae close to each other in lateral to medial direction. Gnathosoma ventrally 79 long (without apodemes), 103 with apodemes; chelicera 123 long. Dorsal length of I-leg: 52, 56, 64, 100, 94, 89; maximum height of I-leg-6, 30; dorsal length of IV-leg: 172, 100, 134, 94, 100, 97; IV-leg-2 with a distal projection and 3-4 thickened setae on medial surface, IV-leg-3 with a large distal projection with a peg-like seta ( Figure 9 D-E).

Female — Not know with certainty. A single female from Caution Creek resembles the male in unpaired anterodorsal plate distinctly longer than wide, but differs in surface ornamentation of dorsal sclerites ( Figure 14K ). Until the male and female are taken from the same site, our assignment is tentative. Here we provide a description of the female specimen from Caution Creek. Idiosoma dorsally 467 long and 350 wide, ventrally 533 long. Dorsal shield as photographed in Figure 14I , 381 long and 341 wide; unpaired anteromedial plate 156 long and 234 wide; unpaired posteromedial plate 222 long and 244 wide; anterolateral platelet

165 long, posterolateral platelet 150 long. Gnathosomal bay 119 long. Gonopore subterminal, elliptical in shape, 78 long and 38 wide.

Palp as illustrated in Figure 10C ; dorsal length/height (in parentheses length/height ratio) of palpal segments: P1, 33/12 (2.8); P2, 58/37 (1.58); P3, 31/27 (1.14); P4, 75/27 (2.75); P5,

34/13 (2.75). Dorsal length of I-leg: 36, 48, 54, 77, 81, 84; dorsal length of IV-leg: 118, 73,

75, 83, 92, 95; IV-leg-2 distally slightly projecting, IV-leg-3 without a distal extension and a peg-like seta ( Figure 10D ).

Etymology — Named after its occurrence in the Longwood Forest. The name is a noun in apposition.

Remarks — This is the second known species of the genus after Tryssaturus spinipes Hopkins, 1967 . The latter species was orginally described from a stream in Tararua Mountains of southern North Island ( Hopkins 1967) and later on reported from several localities in

North and South Island. From the new species, T. spinipes can be easily distinguished in the morphology of the dorsal shield with the anteromedial plate distinctly longer than wide, and with a characteristic reticulate ornamentation (as shown in Figure 14H ). Further, the male of T. spinipes , has a group of thickened setae (around 12 setae as illustrated on Figure 317 in Cook 1983) on medial surface of IV-leg-2 which does not exist in the new species, which has 3-4 strong setae on medial side of the latter segment

Distribution — Known from two localities from South Island.

Figures

Figure 9 Tryssaturus longwoodn. sp., male, stream crossing road to Bald Hill. A – idiosoma, dorsal view; B – idiosoma, ventral view; C – palp; D-E – IV-leg-2-6; F – I-leg-5 and -6. Scale bars = 100 μm.

Figure 10 Tryssaturus longwoodn. sp., female, Caution Creek. A – idiosoma, dorsal view; B – idiosoma, ventral view; C – palp; D – IV-leg- 2-6. Scale bars = 100 μm.

Figure 14 Photographs of dorsal shield. A – Evidaturus scopticus Cook, 1983, male holotype, stream on Wainui Rd (from: <https://collections.tepapa.govt.nz/object/125039>); B –Kritaturus sornus Cook, 1983, female, Longbeach Creek; C – K. jacundusCook, 1983,