The Effect of Interspecific Competition on the Distribution and Size of Darters of the Subgenus Catonotus (Percidae: Etheostoma)

Distributions of seven slab-pool-inhabiting species of Catonotus form an almost totally nonoverlapping mosaic in the Cumberland, Tennessee and Green river systems, which appears to be responsible for their allopatry.

Abstract

Distributions of seven slab-pool-inhabiting species of Catonotus form an almost totally nonoverlapping mosaic in the Cumberland, Tennessee and Green river systems. In contrast, riffle-inhabiting species of Catonotus are both sympatric and syntopic with each other and with species of Catonotus that inhabit slab pools. Competition among the slab-pool species for habitat space appears responsible for their allopatry. Maximum size (largest standard length known) varies interspecifically and geographically among Catonotus, and for most populations is apparently determined by the presence or absence of E. squamiceps.