Efficiency of anesthetics on female gastropod Littoraria angulifera

The present study evaluated the effect of three anesthetics at three concentrations, menthol (C10H20O) (1%, 1.5%, 2%), eugenol (C10H12O2) (0.5%, 1%, 1.5%) and magnesium chloride (MgCl2) (4%, 7%, 10%) diluted in distilled water on the gastropod Littoraria angulifera. Twenty females were tested for each concentration with shell height varying between 18.3 and 26.1 mm (n = 180), all collected from the same site. The time of induction and recovery of the sedative effect, as well as the survival rate, were assessed. The animals were kept within aquaria at a temperature of 25±1°C and observations were made every 30 minutes since the beginning of the anesthesia for up to 2 hours. After this period, the animals were kept in aquaria and observed during the following 15 days for survival evaluation. Only MgCl2 caused a sedative effect on L. angulifera. At 4% and 7% MgCl2 solutions, 20% and 95% of animals were anesthetized after 2 hours, respectively, and at 10% all animals were anesthetized after 1 hour. In conclusion, L. angulifera can be efficiently anesthetized in a 10% MgCl2 solution for 1 h and the recovery occurs in 30 minutes with no apparent side effects on behavior and survival.