In the Asia-Pacific region, the COI DNA test revealed the divergence of the bivalve mollusc Mactra chinensis into three species; can these species be distinguished using shell coloration and sperm structure?

Abstract According to COI DNA barcoding testing, the marine bivalve mollusc Mactra chinensis , which is native Asia-Pacific region, diverged into three species. These species were preliminary characterized as M. clade I, II and III. To find out whether it possible morphologically distinguish samples representing genetic clades, we examined color of shells structure spermatozoa. It was found that number detected coloration types exceeds In addition, shown individuals belonging same can have different colors. Consequently, impossible choose one type shell a species-specific trait. For sperm, sperm morphological patterns in each are consistent with model described previous reports. However, single variant also not applicable discriminate between derived from since heterogeneous variants spermatozoa differing length acrosomal rod found. We hypothesized divergence could cause shift towards predominance variants, morphs be quantitatively dominant molluscs clades. I Thus, useless traits. parameters specific geographic regions, seems unique environmental factors determine morphology. As result, both used geographical forms regardless particular clade. Here propose introduction identifiers, sets criteria origin specimens complex.