Comparative Venomics of and and Closely Related Vermivorous Cone Snails.

Cone snail venom biodiversity reflects dietary preference and predatory and defensive envenomation strategies across the ≈900 species of . To better understand the mechanisms of adaptive radiations in closely related species, we investigated the venom of two phylogenetically and spatially related species, and of the clade. Transcriptomic analysis revealed that the major superfamily profiles were conserved between the two species, including 68 shared conotoxin transcripts. These shared transcripts contributed 90% of the conotoxin expression in and only 49% in , which showed greater toxin diversification in the dominant O1, I2, A, O2, O3, and M superfamilies compared to . On the basis of morphology, two additional sub-groups closely resembling were also identified from One Tree Island Reef. Despite the morphological resemblance, the venom duct proteomes of these cryptic sub-groups were distinct from We suggest rapid conotoxin sequence divergence may have facilitated adaptive radiation and the establishment of new species and the regulatory mechanisms facilitating species-specific venom evolution.