Comparative life-cycle, biomass and secondary production of three sympatric freshwater gastropod species
Abstract
The life cycles, biomass and secondary production of three sympatric freshwater basommatophoran snails, Lymnaea palustris (MÜller), Physa fontinalis Linnaeus and Anisus rotundatus (Poiret) were studied during two years in a freshwater ditch. L. palustris exhibited an iteroparous life-cycle whereas the two other species presented a semelparous life-cycle, adults died just after oviposition. L. palustris secondary production (dry weight) value was higher (P = 11 298.4 mg 0.1 m−1 yr−1) than those of P. fontinalis (P = 846.3 mg 0.1 m−2 yr−1) and A. rotundatus (P = 1192 mg 0.1 m−2 yr−1).