The effect of temperature on the development of Angiostrongylus cantonensis (Chen 1935) in Pomacea canaliculata (Lamarck 1822).

Angiostrongyliasis cantonensis, clinically presented as eosinophilic meningitis, is a snail-borne parasitic disease. We studied the effects of different temperatures on the larval development of Angiostrongylus cantonensis in the freshwater snail Pomacea canaliculata. Six groups of snails were infected and each group was cultured under different temperature conditions. At predefined intervals, four snails from each group were dissected to examine the larval development. The development-time curve of each group was drawn according to the fraction of third-stage larvae present. The developmental time was defined as the time needed until 50% of the first-stage larvae developed into third-stage larvae. A linear regression model was established based on the time (D; in days) and the corresponding temperature (T; in degrees Celsius): DT = 15.04 x D + 262.53. The threshold temperature for larval development was 15.04 degrees C and the thermal constant was 262.53 degree-days. These parameters could be helpful in estimating the number of parasite generations in a year and the impact of climate change on the distribution of A. cantonensis.