Moll. Res. 17: 49-109 (1996). 
Three new morphologically and genetically determined species of 
hydrobiid gastropods from Dalhousie Springs, northern South Australia, 
with the description of a new genus 
W. F. Ponder, D. J. Colgan, T. Terzis, 
S. A. Clark and A. C. Miller 
Australian Museum 
6 College Street, Sydney, New South Wales 2000 
А new genus (Dalhousia) containing two new species (D. globosa and D. harrisi), and а 
new species of Fluvidona (F. centralia) are described from Dalhousie Springs in northern 
South Australia. Allozyme data from 77 populations are presented and used to justify the 
separation of the two species. Dalhousia is the sister group of Fonscochlea from the Lake 
Eyre Supergroup springs but differs from that genus in females having a single sperm 
pouch. Species of Fluvidona are otherwise found in streams and rivers, mainly in south 
eastern Australia, F. centralia being the only species known from central Australia. The 
anatomy of the three species is described and a summary of their variation, based on shell , 
measurements and allozymes, is presented. 
Introduction "s 
SE are many artesian springs associated with the Great Artesian Basin (GAB) іп South 
ES (Ponder, 1986; Boyd, 1990) and they are of great interest, biologically, limnologically and 
Po SE Their considerable conservation significance has been recognised (Harris, 1981, 1993; 
T er, 1985, 1986, 1995; DEST, 1994). 
ҚАНЫН groups of artesian springs аге associated with the section of the GAB in South 
[mre 1a. The largest group, the Lake Eyre Supergroup (Habermehl, 1982; Ponder, 1986), lies in a 
SM nning roughly south west between Marree and Oodnadatta. The other major group, Dalhousie 
ARS comprises approximately 80 springs in a small area (about 70 km?) of far northern South 
1982. ae Which together have the largest natural discharge of water from the GAB (Habermehl, 
Sg E 1989). Aspects of their history, biology, limnology and geology are described in Zeidler 
Ge er (1989). The springs contain а number of endemic aquatic animals, including fishes 
No р О, Crowley & Ivantsoff, 1990), amphipods (Zeidler, 1989, 1991) and hydrobiid 
Gs Gr 5 (Ponder, 1989 and herein). The latter are by far the most abundant and conspicuous of 
e етіс aquatic invertebrates, as is the case in other GAB artesian springs (see below) and also 
a Ss Spring systems іп the Americas (e.g. Hershler, 1985; Hershler and Landye, 1988; Hershler 
1994) а, 1987). These snails are generally associated with long-term permanent water (Ponder, 
E See on the hydrobiid snails of the Lake Eyre Supergroup springs demonstrated considerable 
d ogical and genetic diversity (Ponder et al., 1989; in press) and hydrobiids from springs 
Clated with the Queensland part of the GAB have been described by Ponder and Clark (1990). 
PORTS survey of Dalhousie Springs was undertaken in 1985, the results presented in Zeidler and 
Ke Іп а review of the aquatic molluscs of Dalhousie, Ponder (1989) recognised an 
€ m ed fauna of “at least six species of hydrobiid snails” based on gross shell differences, but 
Be a SE variable shell morphology encountered in the springs. Major differences in shell 
BETEN Shape were noted between populations inhabiting different environments, even associated 
dub п mele spring. Preliminary morphological analysis indicated that standard techniques were not 
© distinguish putative taxa. A second major survey of the fauna was undertaken in 1990 to 
