1 Introduction
Corbicula fluminea belongs to the family Corbiculidae, genusCorbicula (Ishibashi et al., 2003; Korniushin, 2004). The clam has a round base and triangular double shells (Figure 1). The surface of the shells is glossy, and the shell color varies with the living environment (Alyakrinskaya, 2005). Shells are brown, yellow, green, or black and are characterized by circular growth lines (Qiu, Shi, & Komaru, 2001). There are three main teeth in the left shell, one in the front, one in the back and one in the side (Thorp & James, 1991). The clam grows rapidly and takes only 73–91 days for sexual maturation (Tao, Deng, & Li, 2016; Gu, & Wang, 2001). Due to this, it has strong reproductive capacity and diffusion ability (Sun, 1995). C. fluminea is native to East Asia, therefore it is also called the Asian Clam. This species is a native shellfish in China, where it displays strong environmental adaptability. As a representative of freshwater macrobenthic invertebrates, clams are an important component of freshwater ecosystems, and this species has an important impact on the diversity of freshwater ecosystems (Ding, Deng, & Cao, 2014; Xiao, 2015). As a bivalve that has successfully undergone radiation in freshwater habitats (Sirirat, Joong, & Foighil, 2000), the clam is widely distributed in lakes and rivers in China. It is also found in Korea, Japan, and Southeast Asian countries (Jiang, & Zhao, 1997), whereas in America and Europe, it is considered as an alien species (Keogh, & Simons, 2019; Kondakov, Palatov, & Bolotov, 2018).