West Lost Lake has a higher production of the crayfish, Orconectes virilis, than does nearby North Twin Lake. The basis for the higher carrying capacity of West Lost Lake lies in its steeper basin slope which extends more of its littoral leaf fall distribution to the deeper waters where the social dominace of males forces the female adults to reside. As a result there is a greater available supply of allochthonous food provided for the female brood stock in West Lost Lake. Even though attached egg production per female breeder is the same in both lakes, more hatchlings are produced in West Lost because it has a greater density of nursery area provided by larger beds of Carex aquatilis var. substricta. Because the survival rate of crayfish throughout life is not different in the two lakes, the higher praoduction in West Lost is attributed to a greater carrying capacity for both young and adults.