Arrenurus (Truncaturus) regulator (Thor, 1925)

Tuzovskij, Petr V., 2020, Description of a new water mite of the genus Arrenurus (Acari, Hydrachnidia: Arrenuridae) from Chukotka, Zootaxa 4802 (2), pp. 383-390 : 388

Key to males of the Arrenurus (Truncaturus) regulator group

1 Dorsal furrow extends laterally onto sides of idiosoma at base cauda ( Fig. 23 )............................. A. viktorovi

- Dorsal furrow terminates on dorsal side of idiosoma ( Figs 13 , 25 )............................................... 2

2 Genital plates broad, short and distinctly expanded laterally, Fig. 26 ( Gerecke et al 2016)................... A. regulator

- Genital plates narrow and rather long, widening somewhat laterally............................................. 3

3 P-2 with three or less dorsal setae, Fig. 29 ( Mullen 1976)............................................ A. lacrimatus

- P-2 with five to seven dorsal setae........................................................................ 4

4 Idiosoma broad, W 775–800 μm, excretory pore located ventrally ( Fig. 16 ), P-2 with. seven dorsal setae arranged in two rows ( Fig. 17 )........................................................................... A. chukotkaensis sp. n.

- Idiosoma comparative narrow, W 560–610 μm, excretory pore located on posterior end of cauda, Fig. 30 ; P-2 with five dorsal setae arranged in a straight row, Fig. 31 ( Habeeb 1954).......................................... A. rufopyriformis

Figures

FIGURES 23–31. Arrenurus,adults; 23–24, Arrenurus viktorovi: 23, idiosoma,dorsal view, 24, idiosoma, ventral view (after Tu- zovskij 1976); 25–26, A. regulator: 25, idiosoma, dorsal view, 26–27, idiosoma,ventral view; 28, pedipalp (after Gerecke et al. 2016); 29, A. lacrimatus, pedipalp (after Mullen 1976); 30–31, A. rufopyriformis, 30, idiosoma, ventral view (after Habeeb 1954; 31, pedipalp (after Mullen 1976); 27, female; 23–26, 28–31, male.

FIGURES 10–14. Arrenurus chukotkaensis sp. n., larva: 10, leg I; 11, leg II; 12, leg III; 13, claws of leg I; 14, claws of leg III. Scale bars: 10–12 = 50 μm, 13–14 = 20 μm.

FIGURES 15–16. Arrenurus chukotkaensis sp. n., male: 15, dorsal view (holotype); 16, ventral view (holotype). Scale bar: 13–14 = 200 μm.

FIGURES 17–20. Arrenurus chukotkaensis sp. n., male: 17, pedipalp (holotype); 18, IV-Leg-4–6 (paratype); 19, claws of leg I (para- type); 20, claws of leg IV (paratype). Scale bars: 17 = 50 μm, 18=100 μm, 19–20 = 20 μm.