Lotic

Darters have evolved to survive in fast moving lotic systems.

Darters have evolved to survive in fast moving lotic systems.

Lotic refers to freshwater ecosystems involving flowing water, such as a river, stream, brook or creek.  Certain fish species are lotic specialists and have evolved to live in higher flow water, such as darters which prefer to live in swift-moving riffles.

Lentic

Cichlids have radiated in the lotic environment of Lake Victoria.

Cichlids have radiated in the lentic environment of Lake Victoria.

Lentic describes freshwater ecosystems characterized by still water and low flow, such as a lake or pond.  Certain fish species have evolved to become lentic specialists, such as the high diversity of cichlid species found in Lake Victoria.