An assessment of tobacco waste for control of the gastropod Tympanotonus fuscatus (Linnaeus) in brackishwater fish ponds

Abstract

The common brackishwater gastropod Tympanotonus fuscatus or “periwinkle” can become a serious pest in tidal fish ponds. Control of the molluscs in fish ponds can be accomplished by using tobacco waste. This paper presents the results of behavioural response and survival of T. fuscatus at varying concentrations of tobacco waste. The time taken for 50% of the animals to escape from the solution increased with increasing concentration. The median times were 23, 28, 40, 62, and 213 min for concentrations of 0.25, 0.50, 0.75, 1.00, and 1.25 g/l. At 2 g/l no animals escaped. Using 1-, 2- and 3-day-old solutions, the escape time decreased with the age of the solution. The median lethal time (50% mortality) for snails exposed to lethal concentrations decreased with an increase in the concentration. At 1 g/l, median lethal time was 216 h, decreasing to 71 h for 2 g/l. At concentrations less than 2 g/l, the snails attempted to escape from the solution, but at this or higher concentrations the snails close the operculum and eventually die.