“…Freshwater sponges can survive extreme environmental constraints ranging from ice to cold and hot water, desiccation, silty floods, anoxy, eutrophy, and high concentrations of chemicals, hydrocarbons, and heavy metals (Old, 1932;Jewell, 1935Jewell, , 1939Sarà and Vacelet, 1973;Harrison, 1974Harrison, , 1977Rader, 1984;Rader and Winget, 1985;Van Soest and Velikonja, 1986;Willenz et al, 1986;Francis and Harrison, 1988;Ricciardi and Reiswig, 1993;Richelle-Maurer et al, 1994a,b;Vacelet, 1994;Reiswig and FIGURE 8.13 Reproductive strategies of most Spongillina display both K and r phases. Miller, 1998;de Ronde et al, 2002;Rota and Manconi, 2004;Müller et al, 2007). On the contrary, gemmule dispersal to colonize new habitats (A′-A′′-A′′′-A′′′′) matches the r phase when unsuccessful events (x) occur (right).…”