Effect of ammonium chloride on Biomphalaria Alexandrina and on its infection with schistosoma mansoni and echinostoma liei miracidia

The LC50 and LC90 of ammonium chloride [NH4C1] were found to be 90 ppm and 130 ppm, respectively. Maintaining of B. alexandrina at low concentrations of NH4C1 [5, 10, 15 and 20 ppm] greatly reduced their survival rate and fecundity. The net reproductive rate was deleteriously affected. This rate was significantly reduced than that of the control snails in all tested snail groups. The reduction in Ro was 86.9%, 90.8%, 93.9% and 96.9%, respectively. The susceptibility of B. alexandrina to infection with S. mansoni and E. Liei miracidia and infectivity of these two parasites were greatly reduced. Increasing the salt concentration increased this reduction. The magnitude of reduction in infection rate was lower in case of E. Liei than that in S. mansoni indicating that E. liei was more tolerant to the effect of this salt than S. mansoni

Ocorrência de Lymnaea columella (Say, 1817)(Mollusca, Pulmonata, Lymnaeidae), no Estado de Goiás. Consideraçöes sobre os parasitos por ela transmitidos / Occurrence of Lymnaea columella (Say, 1817)(Mollusca, Pulmonata, Lymnaeidae) in the State of Goiás and commentes about the ralationships of the molluc with the transmission of some parasites

Os autores relatam a primeira ocorrência de Lymnaea columella (Say, 1817) no Estado de Goiás, ressaltando a importância da espécie como hospedeiro intermediário de vários parasitos dos animais domésticos, dos quais, alguns são agentes de zoonoses no Brasil e em outros países. Também fazem considerações sobre os parasitos transmitidos ou possivelmente transmitidos por este molusco, já assinalados no Brasil