VII. DESERT FISHES
443
Fig. 8. Distributions of two species of Arizona cyprinid fishes. Dots represent
collection sites for longfin dace since 1960; open circles denote former localities
of occurrence. Closed triangles are for collections of speckled dace since 1960;
open triangles indicate now-extirpated populations. Of 17 sites at which both species
occurred at some time, 5 now support neither species, and 12 support longfin
dace alone, an indication of stream deterioration and upstream invasion of the
latter, a low desert species, to higher elevation as stream temperatures ameliorate
and speckled dace are forced upstream.