关键词: COI, Pomacea canaliculata, P. maculata, 分子鉴定, 遗传多样性, 入侵种

Abstract

Golden apple snails seriously damage crops and aquatic ecosystem in China. Two invasive apple snail species, Pomacea canaliculata and P. maculata, have been reported in China since 2010. Only the distribution of P. canaliculata was reported in Zhejiang Province. It is difficult to distinguish the two species due to their close morphological characteristics and high diversity of shell morphology, which are influenced by both environmental factors and food types. We collected samples from seven localities from Zhejiang Province and sequenced 101 individuals of mitochondrial COI fragments of the DNA barcode region. We also downloaded 55 sequences of five species of the P. canaliculata group, which included all public sequences of P. lineata, P. dolioides, and P. paludosa, and South American sample sequences of P. canaliculata and P. maculata. Analyses including similarity alignments, DNA barcoding gaps, and phylogenetic relationships, revealed that COI sequences were effective to distinguish apple snail species. We detected P. canaliculata and P. maculata distributed in the Jianggan region of Hangzhou, while only P. canaliculata was distributed in the Putuo region of Zhoushan, the Shanyu and Xinchang regions of Shaoxing, the Ouhai region of Wenzhou and the Xihu regoin of Hangzhou. P. canaliculata revealed a much wider distribution range. P. canaliculata and P. maculata were collapsed into 4 haplotypes and 2 haplotypes, respectively. There were 1 to 3 haplotypes in each locality, which indicated a low genetic diversity. The phylogenetic analyses deduced that P. canaliculata and P. maculata were probably introduced from Argentina and Brazil, respectively.

Key words: COI, Pomacea canaliculata, P. maculata, molecular identification, genetic diversity, invasive species