Duda, Thomas F. JR. Kohn, Alan J., Palumbi, Stephen R. 2001. Origins of diverse feeding ecologies within Conus, a genus of venomous marine gastropods. Biological Journal of the Linnean Society 73: 391-409.

Conus is a very species-rich genus of predatory marine snails with a diet range that matches its species diversity. Have this genus' diet specializations evolved many times or did they evolve conservatively with only one to a few origins of each form of diet?

Conus includes more that 500 living species and hundreds of extinct species as well. In addition, although shell morphology varies very little from one species to another, life history and ecological attributes vary greatly. Three general feeding groups in this genus have arisen, with respective diets consisting of fish, worms and other mollusks.

72 Conus species from the various feeding groups were obtained from throughout the Pacific, Atlantic and Indian Oceans. DNA was extracted from each species and analyzed to create several tentative phylogenetic trees. Estimated time scales from fossil records were then applied to the tree. Several obvious phylogenetic clusters of species were observed.

DNA results showed a conservative evolution pattern. A diet of errant polychaetes appears to be the ancestral Conus form. Two clades of molluscivores, and two of the three clades of piscivores share a common ancestor that was likely an snail that preyed on a diet of errant polychaetes. The third clade of piscivores may have arisen from a sedentary vermivorous ancestor.

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(posted Mar. 24 2009)