[Dependence of size of the great ramshorn (Planorbarius corneus L., Gastropoda, Pulmonata) on population density].

The dependence of the mean mass (M) of great ramshorn (Planorbarius corneus) individuals on the number of individuals (N) that reached 82-days age in culture with constant conditions--water volume 50 ml, temperature 25 degrees C, and redundant food (dandelion leaves)--has been studied. The relationship between these parameters has been shown to be approximated by the equation M = 139/N mg. Consequently, at least in these conditions the total biomass of same-aged ramshorn individuals in the culture is relatively constant and does not depend on the number of individuals in the population.