ChileanJAR

Standard artificial breeding of the freshwater snail Physa venustula for ecotoxicological evaluation of pesticides was realized. The bioassays were standardized with a breeding protocol of four batches of P. venustula fed with a solution of Cereal Leaves™ plus fishmeal and Chlorella vulgaris in our laboratory. The oviposition had a downward trend through the time. The eggs were hatched between 7 and 14 d under experimental conditions. The average of eggs per capsule was 12.04 ± 10.66 (range= 1 to 45) and the average fecundity percentage was 65.22%. The snails which produced more egg mass had a lower average number of eggs. The Cereal Leaves™ proved to be a more complete diet for the freshwater snail P. venustula compared to the microalgae Chlorella vulgaris. The morphologic characteristics of the eggs and the behavior of the immature forms are described. The rotifer Philodina acutiformis was a biological contaminant that did not permit the normal growth of the eggs in the cultures. The protocol of ecotoxicological assay using P. venustula has the following advantages: wide distribution in the neotropic, reliability, repeatability, high sensitivity in comparison with other snails and short duration of the assay.