Chologaster aggasizi Putnam.--The spring cavefish was not a subject 
during this investigation because of the thorough study of its 
ecology conducted for the U. S. Forest Service by Norbert Welch 
in 1973. Remarks here about its ecology will therefore be confined 
to observations that supplement Welch's report. The fish may get 
into the swamp at any time when they are swept out from a spring. 
Casual observations by one of us (Smith) suggested that tempera- 
ture was the critical factor and that during winter months indi- 
viduals could survive water temperatures in the swamp but not 
during the summer. Welch correlated the number of individuals in 
Springs with the volume output of the springs. It thus appears 
that temperature has nothing to do with the species occurrence 
in the swamp. Individuals are probably swept into the swamp 
during the very high winter flow of the springs and subsequently 
unable to find their way back to the spring mouths. 
Gunning and Lewis's (1955) figure of 7.8 percent of their total 
Sample was probably the result of selective sampling inasmuch as 
they mentioned that dipnetting, which is the most efficient method 
of capturing the cavefish, was one of their methods. The presence 
of the spring cavefish in the swamp is an accident that occurs 
ee wien a Spying is adjacent to the swamp or has a high rate 
of flow 
Other Species. --Comparison of relative abundances of most of the 
Species encountered in this survey and that of Gunning and Lewis 
in the early 1950's reveals relatively little change. Some 
differences are to be expected because of succession, year-to-year 
fluctuations in spawning success, and different sampling methods. 
Although most the species appear to have changed little in abun- 
dance, three show rather dramatic changes. 
Gunning and Lewis found the pirate perch, Aphredoderus sayanus, 
to be the most common species and to comprise almost 36 percent 
of their total sample. We found it to rank eighth and to make up 
only 3 percent. We found the bluegill, Lepomis macrochirzus, to 
be most common at 23 percent of the total; they found it to make 
up only 1 percent. The two fishes are conceivable competitors, 
and modifications of the swamp:that create pondlike habitats 
(excavating fishing ponds, beaver ponds, destruction of aquatic 
vegetation, etc.) migh favor the bluegill, which is less dependent 
upon shallow, well-vegetated waters. The mosquitofish, Gambusia 
agsfinis, appeared to be more abundant during the recent study but 
may reflect only differences in sampling methods. 
Wy 
