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S.C. Choy 
0.4 of second endopod segment, distal margin with 
long plumose setae. 
First pereiopod (Figure Id) reaching tip of basal 
antennular segment; chela length 2.3 X width, 
movable finger 1.3 X as long as palm, length 3.3 X 
width; finger tips rounded, without hooks, setal 
brushes well developed. Carpus attached to chela 
ventrally, excavated disto-dorsally, length 2.5 X 
width, 0.91 X chela length, 1.2 X merus length. 
Merus 0.7 X as wide as carpus. Ischium length 0.48 
X merus length. Epipod present. 
Second pereiopod (Figure le) reaching tip of 
second segment of antennular peduncle, more 
slender and longer than first pereiopod. Chela 
length 2..4 X width; movable finger length 3.2 X 
width, 1.5 X as long as palm; finger tips without 
hooks, setal brushes well developed. Carpus 
slightly excavated distally, length 5.3 X width, 1,3 
X chela length, 1.2 X merus length. Ischium length 
0.52 X merus length. Epipod present. 
Third pereiopod (Figure li) over-reaching 
antennular peduncle tip by about 0.33 distal 
propodus. Dactylus length 3.1-4.2 X width, ending 
in prominent claw-like hamate seta surrounded by 
simple setae, behind which posterior margin bears 
4-7 shorter spiniform hamate setae. Propodus 
length 14.0-14.6 X width, 3.0-3.7 X dactylus length, 
posterior margin and lateral surface bearing two 
rows of small spiniform hamate setae. Carpus 
length 0.7 X propodus length, distal projection 
feebly developed, posterior and lateral surfaces 
with up to 5 small hamate setae. Merus 1.7-2.2 X 
length of carpus, with 1-3 strong, movable 
spiniform hamate setae along posterior margin. 
Ischium 0.2-0.3 X length of merus. Epipod present. 
Fourth pereiopod reaching tip of second segment 
to tip of third segment of antennular peduncle, 
morphology similar to third pereiopod. Dactylus 
length 3.5 X width, ending in prominent claw-like 
hamate seta and 4-7 shorter spiniform hamate 
setae along posterior margin. Propodus length 14.0 
X width, 4.5 X length of dactylus, bearing two rows 
of hamate setae along posterior and lateral 
surfaces. Carpus 0.7 X length of propodus, with up 
to 7 small hamate setae along posterior and lateral 
surfaces. Merus about 2.1 X length of carpus, with 
3-4 spiniform hamate setae on postero-lateral 
margin. Ischium 0.25 X length of merus. Epipod 
present. 
Fifth pereiopod (Figure If) reaching tip of second 
segment to tip of third segment of antennular 
peduncle. Dactylus length 4.3 X width, ending in 
claw-like apical hamate seta, bearing comb-like 
row of 35-45 hamate setae on posterior margin. 
Propodus length 15.7 X width, 3.0 X dactylus 
length, bearing two rows of 15-20 short hamate 
setae on posterior margin. Carpus length 0.5-0.6 X 
propodus length, bearing 2-6 short hamate setae, 
distal projection well developed. Merus distinctly 
shorter (0.8) but broader (1.3) than propodus, 
bearing 2-4 large spiniform hamate setae. Ischium 
about 0.4-0.5 X length of merus, with simple setae. 
Epipod absent. 
Abdomen (la) well developed, rotund, glabrous, 
2.1 CL; sixth abdominal segment 0.47-0.67 CL, 
length 1.9-2.3 X depth. Second abdominal somite 
depth (from top of tergum to ventral margin of 
pleura) about 0.96 CL in fully developed non- 
ovigerous female, about 0.80 in males and juvenile 
females. 
First pleopodal endopod (Figure lh) length in 
adult male 2.2 X proximal width, 0.27-0.33 X 
exopod length, ovate, wider proximally, broadly 
rounded distally, inner margin bearing long 
plumose setae, outer margin with short plumose 
setae proximally and longer ones distally. 
Appendix interna absent. 
Second pleopodal endopod length in adult male 
about 0.90 X exopod length, inner border near base 
with long marginal and submarginal hamate setae. 
Appendix interna reaching beyond middle of 
appendix masculina, with many retinaculae 
distally. Appendix masculina subcylindrical, long 
hamate setae distally and on inner lateral margin. 
Telson (Figure lg) 0.4-0.5 CL, equal to or just 
shorter than sixth abdominal segment, tapering 
posteriorly, ending in rounded margin, dorsal 
surface with 3-5 pairs of short hamate setae. 
Posterior margin rounded, with 8-10 spine-like 
setae, one or two outer-most pairs much shorter 
than adjacent, somewhat sigmoid, inner pair which 
in turn is generally thicker and longer than its 
adjacent inner ones. Uropods distinctly longer than 
telson; diaeresis on exopod with 8-10 small hamate 
setae. 
Etymology 
The specific epithet refers to the habitat from 
where the species was collected (Latin: spelunca = 
cave). It is used as a noun in apposition. 
DISCUSSION 
Caridina spelunca sp. nov. is the first in the genus 
to be described from Western Australia. Its habitat 
and sympatric fauna have been described by 
Humphreys (1995). It somewhat resembles Caridina 
xveberi De Man 1892 (which is a wide ranging Indo- 
Pacific species but not yet reported from Australia) 
in rostral structure but can be easily distinguished 
from this and other morphologically similar species 
on the basis of a combination of the following 
characters in C. spelunca: absence of a median spine 
on the posterior telsonic margin; posterior telson 
margin with fewer and shorter intermediate setae, 
each lacking septum and annulus; carpus of first 
pereiopod longer and not deeply excavated and 
the absence of an appendix interna on the endopod 
