Bacteria are present in large numbers in lotic waters. Perlidae are usually lotic and lentic erosional. Seasonal patterns in species diversity and niche parameters of lotic predator guilds. Insects have developed several strategies for living in the diverse flows of lotic systems. River ecosystems are prime examples of lotic ecosystems. Up to 90% of invertebrates in some lotic systems are insects. Invertebrates can be organized into many feeding guilds in lotic systems. Invertebrates are important as both consumers and prey items in lotic systems. Dams alter the flow, temperature, and sediment regime of lotic systems. Ecological correlates of species richness in three guilds of lotic macroinvertebrates. The fry appear to be adapted to lotic water. Fish are probably the best-known inhabitants of lotic systems. Streams are an example of a lotic habitat Hong Kong. The creek chubsucker is an important species in lotic water systems. Unidirectional water flow is the key factor in lotic systems influencing their ecology.