RESUMO
Abstract: A three-year breeding experiment was conducted in a paddy field in Zixing City of Hunan Province, South-central China to study the characteristics of golden apple snail (Pomacea canaliculata) reproduction under natural conditions. Under the natural conditions in southern Hunan Province, the snails could approximately reproduce three generations per year. The average sexual maturity periods of the first, the second, and the third generation of the female snails were 59.3, 45.4 and 213.0 days, respectively, and those of the male snails were 4.3 days earlier than the females'. The natural sex ratio of the females to the males was 1.54:1. The average copulation duration was 19.2 hours, but spawning did not always occur after each time of copulation. The number of the egg masses produced by the females per month was significantly positively correlated with the mean monthly air temperature (r = 0.756) , while the average incubation duration of the egg masses was significantly negatively correlated with the daily air temperature (gamma = -0.726x + 23.064, r = -0.980). The average incubation time of the egg masses was 20.7 days, average incubation rate was 44.1%, and the average life expectancy of the female and male snails was 2.40 and 1.98 years, respectively. A female snail in its lifetime could averagely spawn 13764 eggs and reproduce 6070 young snails.
