Records of the Western Australian Museum 18: 233-261 (1997). 
Australian water mites of the genus Arrenurus, with the description of 
twelve new species from northern and western Australia 
(Acari: Hydrachnellae: Arrenuridae) 
Harry Smit 
Emmastraat 43-a, 1814 DM Alkmaar, The Netherlands 
Abstract - Two new subgenera of the genus Arrenurus, viz., Dividuracarus 
(type species Arrenurus (Dividuracarus) tripartitus sp. nov.) and 
Brevicaudaturus (type species Arrenurus lohmanni Piersig, 1898), and 12 new 
species, viz., A. (A.) ensifer, A. (A.) harveyi, A. (A.) Uliaceus, A. (A.) 
manlonensis, A. (Dividuracarus) gereckei, A. (Dividuracarus) tripartitus, A. 
(Megaluracarus) caeruleus, A. (Megaluracarus) gilvus, A. (Micruracarus) 
anbangbang, A. (Micruracarus) jabiruensis, A. (Micruracarus) purpureus and A. 
(Micruracarus) separatus are described from Northern Territory and Western 
Australia. Further, a description is provided for the females of A. 
(Brevicaudaturus) lohmanni Piersig, A. (A.) balladoniensis Halik and A. 
(Megaluracarus) vanderpalae Smit, while a more detailed description is given 
for A. (Megaluracarus) thienemanni K.O. Viets. In addition, three species are 
reported new for the fauna of Australia. A key is given for the Australian 
species of the genus Arrenurus. 
INTRODUCTION 
Two genera of the water mite family Arrenuridae 
have been reported from Australia, Wuria and 
Arrenurus. Although the genus Arrenurus has a 
cosmopolitan distribution and is one of the most 
species-rich in the water mites, not more than 20 
species and subspecies have been reported from 
Australia (see Table 1). These species belong to the 
subgenera Arrenurus, Megaluracarus, Micruracarus 
and Truncaturus. Only one species of Wuria, W. 
boutit, is known (Harvey 1989). 
On a trip through the Northern Territory and 
Western Australia, areas seldom visited by 
acarologists, I collected 15 Arrenurus species new 
for the fauna of Australia, of which 12 species are 
new to science. Further, two new subgenera of this 
genus are described. A number of females of 
previously known species are described for the 
first time, and three species new to the Australian 
fauna are reported, i.e. Arrenurus gracilipes Piersig, 
A. lohmanni Piersig and A. rouxi Walter. 
Separate keys are given for the males and 
females of the Australian members of the genus 
Arrenurus. 
All materia! has been collected by the author. 
Western Australia and Northern Territory 
holotypes and paratypes have been deposited in 
the Western Australian Museum (Perth) (WAM), 
and in Northern Territory Museum (Darwin) 
(NTM) respectively. Further, paratypes and almost 
all non-type material have been deposited in the 
Zoological Museum of the University of 
Amsterdam (ZMA). 
The following abbreviations have been used (see 
Figure 9): Ll-4 lateroglandularia 1-4; Al-2 pre- 
and post-antennal glandularia; Dl-4 
dorsoglandularia 1—4; CXI—4 coxal plates 1-4; PI- 
PV palp segments 1-5; l.p. ligulate process; SMF - 
Forschungsinstitut und Naturmuseum 
Senckenberg. All measurements are in pm, 
measurements of leg and palp segments are of the 
dorsal margins. Measurements of paratypes in the 
description of new species are given in brackets. 
Unless otherwise stated, all species have the 
second, third and fourth legs with numerous 
swimming setae 
SYSTEMATICS 
Arrenurus (Arrenurus) balladoniensis Halfk 
Figures 1-2 
Arrenurus balladoniensis Halik, 1940: 283; Halik, 
1941: 106; Cook, 1986: 305; Smit, 1992: 106. 
Arrenurus Cjuadripapillatus Lundblad, 1941: 120; 
Lundblad, 1947: 74. 
Material Examined 
Australia: Northern Territory: 13 6 ,13 $, ponds 
in Ormiston Creek, Ormiston National Park, 6 
August 1994 (ZMA). Western Australia: 2 6, 2 9, 
Lake Monger, Perth, 26 August 1994 (ZMA). 
