Ancylidae 4 Biomphalaria 4 Biomphalaria straminea 4 Biomphalaria tenagophila 4 Canna glauca 4 Chaco Region 4 Cimex 4 Drepanotrema 4 Drepanotrema cimex 4 Drepanotrema lucidum 4 Eichhornia 4 Eichhornia crassipes Gastropoda 4 Hydrobiidae 4 Hydrocotyle 4 Hydrocotyle ranunculoides 4 Intermediate-hosts 4 Panicum 4 Panicum elephantipes 4 Paraná River 4 Pistia stratiotes 4 Planorbidae 4 Schistosomiasis 4 Stratiotes 4 Vector-ecology 4