Chapter 18 - Fishes

Abstract

This chapter deals with the subject of fishes. It begins with a few general topics, shedding light on the anatomy of a fish, their feeding roles, habitat and behavior, and some promising new efforts to develop bioassessment tools based on the diversity of the fish assemblage found at a site. It then examines many of the major families of freshwater fishes occurring in rivers and streams of North America. It also provides more detailed coverage of a half dozen or so families likely to be of particular interest to river enthusiasts and say only a few words about others. All fish species show some level of habitat specialization, and some are extremely specific. This chapter also highlights a number of examples in the treatment of various families of fishes. It is good to keep in mind that fishes, like any organism, exhibit an array of adaptations that fit together to make the total organism. An experienced stream ecologist can read a stream for signs of health or abuse and make a pretty fair assessment. A fish biologist can sample the fishes, and tell whether the seine haul includes good diversity, including species requiring special habitat and intolerant of pollution, or whether the collection yields only hardy generalists.