著者
Haruko Yoshie Yoichi Yusa
出版者
JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY
雑誌
Applied Entomology and Zoology (ISSN:00036862)
巻号頁・発行日
vol.43, no.4, pp.475-482, 2008-11-25 (Released:2008-11-30)
参考文献数
24
被引用文献数
21 23

We studied the predatory potential of the turtle Chinemys reevesii on the apple snail Pomacea canaliculata using two series of experiments. First, we investigated the relationship between turtle body size and the maximum size of snails consumed over a period of 3 days within 0.37 m2 containers. The maximum snail size consumed was positively related with turtle size. Secondly, we investigated the predation of snails by turtles over a period of 8 weeks. We released 200 snails (10–30 mm shell height) and an adult turtle (155–183 mm carapace length) into each of two 2.08 m2 plots with soil and rice plants. Subsequently, snail density was monitored every week and 200 snails were added to low density plots up to twice a week. Two control plots with the same initial density of snails but without turtles were also monitored. The density and survival rate of snails were lower in plots with a turtle than in control plots. We estimated that a single turtle consumed >2,000 snails in 8 weeks. In addition, the biomass of duckweed (given as food for snails) was greater in turtle plots than in control plots, suggesting that the presence of turtles had an indirect effect on weed.