INTRODUCTION 



Although Montana harbors a large number of caves (see Campbell 1978), the faunas 

 these caves support have received relatively little attention. Bats are the best-documented taxon, 

 but even this group is poorly studied in the state (see Hendricks et al 2000 for the only published 

 account of a cave bat fauna). To date, only two species of terrestrial troglobitic (cave obligate) 

 invertebrates (the harvestman Ctyptohuims cavicolus [= Sclerohomis cavico/ens] and the 

 springtail Oncopodura criiciala) have been described from Montana (Nicholas 1960), both of 

 which are endemic to Lewis and Clark Caverns. 



The aquatic cave fauna of Montana is even less well known. Four endemic species of 

 subterranean amphipods in the genus Stygubromus have been collected and described from water 

 wells in Montana (Holsinger 1974). but none of these so far have been reported associated with 

 caves. The only description of cave-associated aquatic invertebrates is in the unpublished report 

 by Campbell et al. (1977), that includes accounts of the aquatic faunas from Algal and Zoo 

 caves, both in Glacier National Park. Here are reported an isopod, an amphipod, and a planarian 

 associated in pools in Algal Cave, and an amphipod in Zoo Cave. Voucher specimens collected 

 from the caves in 1977 were sent to experts, but their fates remained unknown. Prior 

 investigations of both caves (Campbell 1975, Campbell et al. 1976) made no mention of the 

 aquatic invertebrates found in each. 



The 1999 trip to Algal Cave was prompted by reports from Sam Martinez (Helena, MT) 

 of white aquatic isopods seen m pools m this cave during a trip in 1998. At this time, neither 

 Sam nor myself were aware of the report of Campbell et al. (1977). However, the significance of 

 Sam's observation was appreciated immediately, because 1) I was unaware of any aquatic cave 

 animals reported in Montana, and 2) 1 knew that as of 1976 there was only one species of isopod 

 known for Montana (Newell 1976), and it was not a cave species. I was also cognizant that the 

 isopod might be Salmaselhts steganothrix, a subterranean species originally described from the 

 Rocky Mountains of Alberta (Clifford and Bergstrom 1976). 



The primary objectives of the 1999 project were 1) identify the isopod species inhabiting 

 Algal Cave, 2) provide a count of individuals occupying the portion of the cave surveyed, and 3) 

 provide a preliminary description of the physical environment occupied by the isopods. 



STUDY AREA AND METHODS 



Algal Cave (=West Tunnel Cave) is located along Going-To-The Sun Highway in the 

 McDonald Creek drainage of Glacier National Park (T35NR17WS35SENE). The gated entrance 

 is at about 1226 m elevation (4020 ft) with a length of 643 m (21 10 ft); the cave is formed in 

 Siyeh Limestone and contains a significant stream passage ending in an impassable siphon 

 (Campbell 1995, Campbell et al 1976, Campbell et al. 1977). Prior to reaching the stream, a 

 series of pools (connected by a slight surface flow of water) are present, beginning about 60 m 

 (200 ft) from the entrance. The passage is narrow at this point (barely shoulder-width in some 

 places at pool-level) Some of these pools may become dry, depending on season and year. 



Collecting equipment was simple vials with 80% ethyl alcohol for preservation of 

 specimens, a turkey baster, medicine dropper, and an aquariaum dip net all for collecting 



