Ecological comparisons of growth and feeding between Pomacea canaliculata and Pomacea scalaris

• Main Authors: Min-Ching Li, 李敏菁
• Other Authors: Li-Lian Liu
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/w992y8

碩士 === 國立中山大學 === 海洋生物研究所 === 96 === The distribution of apple snail Pomacea canaliculata is islandwide but Pomacea scalaris is only found in southern Taiwan. In order to gain more information on the not well-known invasive species of P. scalaris, the growth and feeding of P. canaliculata and P. scalaris were studied. The hatching period of P. canaliculata (10.4±1.3 days) was shorter than that of P. scalaris (12.2±2.3 days). And, the hatching size of P. canaliculata was also smaller. Two weeks after hatching, a significant higher growth rate in P. canaliculata had been found. The 75-day growth equations for P. canaliculata and P. scalaris were y = 0.29x + 1.09 (p < 0.001) and y = 0.16x + 1.68 (p < 0.001), respectively. Feeding structures of mandible, radulae, central tooth and stomach in P. canaliculata were larger than that of P. scalaris. But, there was no significant difference in the length of gut between the two species. Food passing time in P. canaliculata (1.4±0.7 days) was less than that of P. scalaris (2.9±0.7 days). And, the approximate digestibility per day of P. canaliculata (44.41±24.02%) was higher than that of P. scalaris. Through the analyses of δ13C, δ15N, stomach content and feces, it is known that they have the same trophic level with similar food sources. Additionally, the values of δ13C and δ15N were significantly different between sites of JiouRu and Wugou-shui, Pingtung. In other words, the feeding environments were different between the two sites. Based on the results, it is concluded that the superiority of growth and feeding performance in P. canaliculata is important in shaping its wide distribution in Taiwan.