Diversity and evolution of conotoxins in Conus virgo, Conus eburneus, Conus imperialis and Conus marmoreus from the South China Sea

► cDNA libraries of the four venom ducts from the South China Sea were constructed. ► 34 novel conotoxins were identified from 1312 transcripts. ► Some novel conotoxins showed unique patterns of cysteines. ► The evolutionary trees of highly expressed T- and A-superfamily were analyzed. ► T-superfamily conotoxins undergo positive selection.