Influence of Global to Regional Zoogeography on Local Fish Assemblages

Abstract

To understand the occurrence of fish in local assemblages, it is necessary to consider the overriding, global influence of zoogeographic history and drainage basin relationships on present-day assemblages. G. R. Smith (1981) concluded that barriers to dispersal (basin boundaries) were of paramount importance in controlling species density and patterns of evolution of fishes. Without Zoogeographic information, experimental assessments of present-day ecological phenomena run the risk of attributing present-day functioning or composition of fish assemblages to extant, adaptive processes, even though composition of those assemblages may relate as much or more strongly to historical events (e.g., Smith, 1981; Mayden, 1987) in either the “deep” or “recent” past that influence which species can occur in a stream or lake. Understanding the evolutionary origins [as much as is known for some groups, cf. Fink and Fink (1981)] or distributional affinities of the individual species in a local assemblage or regional fauna is of importance, as is an understanding of geological events affecting the location, in making any predictions about comparative ecology of species or assemblages.