The Ecology of Running Waters

abundant adults Africa algae amount amphipods animals aquatic areas Baetis benthic benthos biological biomass breeding brown trout caddis-worms carbon cent channel Chironomidae cm./sec Creek current speed cycles cyprinids darters detritus diatoms Diptera discharge downstream drift ecology effect eggs emergence Ephemerella Ephemeroptera Europe factor fairly fauna feed fish flow freshwater Gammarus genera genus Gessner gravel growth habitat hatch Hydropsyche Hynes important increase insects invertebrates lakes large numbers larvae less Limnol live mayflies Minckley move normal North America number of species numbers nymphs observed occur Oligochaeta organic matter oxygen particles period periphyton plankton plants Plecoptera populations probably production Rhithrogena rhithron riffles rivers and streams rotifers running water running-water salmon samples sand season seen Shadin shown silt similar Similarly Simuliidae Simulium small streams snails specimens spring stoneflies stones stony stream bed stream-dwelling substrata substratum summer surface temperature tend Trichoptera trout types upstream varies VIII winter zone