Abstract: In order to study the phylogenetic relationships of eight species of abalone in different geographical populations, and to provide molecular biological basis for the identification of the species and the genetic breeding of abalone, this study used 8 kinds of abalone as the experimental materials. The whole sequences of 8 CO I genes were obtained by PCR amplification technique, the other 10 were found from GenBank. Through comparative analysis, it was found that the total length of CO I gene was 1542 bp, which encoded 513 amino acids, and the content of A + T was more than G + C. There were 526 mutation sites, and the mutation rate was 34.11%, while the variation rate of amino acid was 7.8%. From the analysis of genetic distance, it was found that the genetic distance of the same species was less than 0.010. The average genetic distance among different species of abalone was between 0.159-0.196. The phylogenetic tree was constructed to get the following conclusions. Abalone genetic evolution was affected by the influence of geographical distribution, but there was no obvious geographical distribution characteristic between different abalone; and Haliotis rufescens and Haliotis fulgens, which were distributed in the Americas, had a close relationship with Haliotis discus hannai distributing in Asia.

Key words: abalone, CO I gene, phylogenetic tree