Departmento de Biquímica, Instituto de Ciências Biológicas da Universidade Federal de Minas Gerais, Centro de Pesquisas de Produtos Naturais, Universidade Federal do Rio de Janeiro, Belo Horizonte, Brazil
Crowding of Biomphalaria glabrata simultaneously inhibits growth and iron uptake. Measurement of the absorption of 59Fe provides a simple criterion for the estimation of crowding. In this way, crowding effect was demonstrate to be related not only to poplation density but also to population size. An inhibitory factor is present in water and feces derived from crowded snail populations.