Records of the Western Australian Museum 18: 67-76 (1996). 
Copepods from ground waters of Western Australia, I. The genera 
Metacyclops, Mesocyclops, Microcyclops and Apocyclops 
(Crustacea: Copepoda: Cyclopidae) 
G.L. Pesce 1 , P. De Laurentiis 1 and W.F. Humphreys 2 
1 Dipartimento di Scienze Ambientali, University of L'Aquila,Via Vetoio, 
1-67100 L'Aquila, Italy 
2 Western Australian Museum, Francis Street, Perth, Western Australia 6000, Australia 
Abstract - Metacyclops mortoni sp. nov. and Mesocyclops brooksi sp. nov. are 
described from ground waters of the Cape Range karst area, northwestern 
Australia. New localities for the species Microcyclops varicans G. O. Sars, 1863 
and Apocyclops dengizicus (Lepechkine, 1900) are reported from the same 
area. The distribution of the above species is greatly extended to 
northwestern Australia. 
INTRODUCTION 
Until recently, notwithstanding the great extent 
and diverse geological, climatic and hydrological 
conditions of the Australian continent, very few 
studies were devoted to the taxonomy of 
copepods, especially of groundwater-inhabiting 
species. Even less is known of the copepod fauna 
of Australia outside Victoria, New South Wales 
and the Northern Territory. 
The apparent scarcity of copepods in Australia 
probably results from a lack of collections over 
much of the continent, particularly from 
subterranean biotopes. 
The number of recent publications on Australian 
freshwater copepods, especially groundwater 
species (Dumont and Maas 1985; Morton 1985, 
1990; Hamond 1987; Dussart and Fernando 1988; 
Timms and Morton 1988; Pesce et al. 1996), reflect 
the growing recognition world wide of the extent 
and importance of groundwater communities 
(Marmonier et al. 1993). Nevertheless, the fresh¬ 
water cyclopid copepods, particularly those from 
northwestern Australia, remain almost completely 
unknown. Therefore, it is not surprising that 
collections from different subterranean habitats in 
this region included two hitherto undescribed 
species of the genera Metacyclops Kiefer and 
Mesocyclops G. O. Sars, and the widespread species 
Microcyclops varicans (G. O. Sars, 1863) and 
Apocyclops dengizicus (Lepechkine, 1900). 
The discovery of Metacyclops mortoni sp. nov. 
increases to two the number of congeners from 
Australia, the others being M. amaudi (G.O. Sars, 
1908) and the subspecies M. amaudi platypus Kiefer, 
1967. 
The genus Mesocyclops is better represented in 
Australia and, besides the new' species, includes at 
least five species viz. M. notius Kiefer, 1981, from 
Queensland and the Northern Territory, M. darwini 
Dussart and Fernando, 1988, from the Northern 
Territory, M. australiensis (= M. thermocyclopoides 
australiensis) (G. O. Sars, 1908), from New South 
Wales, Victoria and Tasmania, M. cutlacuttae 
Dumont and Maas, 1985, from the Northern 
Territory and M. thermocyclopoides Harada, 1931, 
from New South Wales and Victoria (Defaye and 
Kawabata 1993). M. pehpeiensis Hu, 1943, was 
recorded by Lim and Fernando (1985), but without 
locality data. 
Finally, this paper considerably extends to the 
west the known distribution of both M. varicans 
and A. dengizicus, which were previously known 
within Australia only from New South Wales, 
Victoria and Northern Territory. 
HABITAT AND ASSOCIATED FAUNA 
Northwestern Australia is arid and on the Cape 
Range peninsula the available water is mostly 
groundwater accessible in a few caves within the 
Cape Range karst and in the general water table of 
the surrounding coastal plain where a freshwater 
lens overlies salt water (Humphreys 1993a, 1993c; 
1993d). The area has a rich stygofauna with tethyan 
affinities (Humphreys 1993b, 1994; Humphreys 
and Adams 1991; Knott 1993). 
Metacyclops mortoni was found only in hand-dug 
wells on the coastal plain of the Cape Range 
peninsula (C-25, C-149, C-273 and Waroora Well) 
and on the Ashburton River (Geebera Well) in 
water ranging in temperatures between 19.6 and 
28.2°C and salinity between 2,550 and 17,044 mg 
L 1 . It was associated with an aquatic fauna that 
included Turbellaria, harpacticoid and calanoid 
