Records of the Western Australian Museum 18: 103-107 (1996). 
Caridina spelunca, a new species of freshwater shrimp (Crustacea: 
Decapoda: Atyidae) from a Western Australian cave 
Satish C. Choy 
Resource Sciences Centre, Queensland Department of Natural Resources, 
1345 Ipswich Road, Rocklea, Queensland 4106, Australia 
Abstract - A new species of freshwater atyid shrimp, Caridina spelunca sp. 
nov., collected from a series of tufa dams within the outflow tunnel of Old 
Napier Downs Cave in the northern Napier Range, Western Australia, is 
described and illustrated. It is the first species of Caridina to be reported 
from Western Australia. Caridina spelunca sp. nov. can be distinguished from 
other species of Caridina by a combination of the following diagnostic 
characters: deep cephalothorax (depth about 0.8 times length), relatively 
small but normal eyes, presence of epipods on the first four pairs of 
pereiopods, lack of a median spine on the posterior telsonic margin and the 
absence of an appendix interna on the endopod of the first male pleopod. 
INTRODUCTION 
Although at least seventeen species of atyid 
shrimps are presently known from Australia (Choy 
and Horwitz 1995), only three species {Stygiocaris 
lancifera Holthuis, 1960, S. stylifera Holthuis, 1960 
and Pycneus morsitans Holthuis, 1986) have been 
reported from Western Australia (Holthuis 1960, 
1986). All three species are obligate troglobites, 
with short-stalked, pyriform eyes which are devoid 
of retinal pigmentation. Most species of the genus 
Caridina are epigean and, although several species 
have been collected from troglons (subterranean 
water bodies), only a few of these exhibit 
troglomorphic characters (Guo et ah, 1996). One 
Australian species, Caridina themiophila Riek, 1953 
was collected in water from an artesian bore but 
neither this nor any of the other seven described 
Australian species of this genus exhibit 
troglomorphic characters. This paper describes a 
new species of Caridina from Old Napier Downs 
Cave in the northern Napier Range in the 
Kimberley, Western Australia. Specimens were 
collected from a series of freshwater tufa dams 
within the outflow tunnel of the cave in the twilight 
zone (Humphreys 1995). These dams are well 
above the level of the plain and no water was 
flowing out of the out of the cave when the samples 
were collected. The lack of troglomorphic 
characters suggests that this species may be a 
facultative troglobite. 
MATERIALS AND METHODS 
The material studied was obtained from the 
Western Australian Museum, Perth (WAM) and 
the Australian Museum, Sydney (AM). The format 
of the description and morphological terms follow 
Choy (1991). Cuticle spination and setation 
terminology follows (Felgenhauer 1992). 
Abbreviations used in the text: CL, post-orbital 
carapace length measured from dorso-lateral 
invagination of the posterior margin to orbital 
margin of carapace; RL, pre-orbital rostral length 
measured from orbital margin of carapace to tip of 
rostrum; SL, body length from tip of telson to 
orbital margin of carapace; x, mean value; s.e., 
standard error. 
SYSTEMATICS 
Family ATYIDAE De Haan, 1849 
Caridina H. Milne Edwards, 1837 
Caridina spelunca sp. nov. 
Figure 1 
Caridina sp. nov.: Humphreys, 1995: 57. 
Material Examined 
Holotype 
Adult 6 , Karst KN-1, Old Napier Downs Cave, 
Western Australia, Australia, 17°14'S 124°39'E, 12 
July 1994, W.F. Humphreys (WAM 422-95), 13.2 
mm SL, 3.48 mm CL, 1.72 mm RL. 
Allotype 
Adult $ Karst KN-1, Old Napier Downs Cave, 
Western Australia, Australia, 11 July 1994, B. Vine 
(WAM 423-95) 15.8 mm SL, 3.64 mm CL, 1.69 mm 
RL. 
