Animals of the open water zone
The limnetic region of this zone contains certain fishes as well as rotifers, zooplankton such as crustacean and protozoan. In the profundal zone occur chemosynthetic autotrophs as well as heterotrophs. The latter may be carnivores or detritus feeders. Further the larger fishes of the lakes are restricted to the profundal zone which also has a well developed series of decomposer population present from top to the bottom.
The bottom which underlies the open water zone contains benthos whose diversity is low. Benthic animals found here are larvae of several insect species such as midges and burrowing flies as well as clams, snails, tube worms and decomposers.