Molecular phylogeny of Conus chiangi (Azuma, 1972) (Gastropoda: Conidae)

Coons chiangi (Azuma, 1972) has been regarded by, several workers as morphologically distinctive enough from other Cows species to merit placement in its own genus (e.g., Taranteconus, Azuma, 1972). We demonstrate using standard molecular markers that this species is related to such well-known species as Coons imperial's Linne, 1758, and Coons regius Gmelin, 1791, which are generally regarded as belonging to the Stephanoconus (Morch, 1852), chide. Stephanoconus has had impressive radiation of species in the new world, but only two species were previously assigned to Stephanoconus from the Indo-Pacific region (Coons imperialis and Coons zonatus Hwass, 1792). We also present data using a toxinological marker for Coons chiangi consistent with its inclusion in Stephanoconus. In at least three species of this chide, a virtually identical peptide toxin (first called alpha-conotoxin Iml from Coons imperialis) was identified. Although the predicted mature peptide toxin sequences are closely similar, significant divergence in the prepro region of the precursors was observed. It is suggested that the conservation of the mature peptide toxin sequence is a result of strong selection related to prey choice in Stephanoconus. The results described here suggest a revised picture of the radiation of Stephanoconus in the Indo-Pacific. In addition to the well-known species Coons imperialis and Coons zonatus, which comprise one group, a radiation of small Coons species in deeper water may potentially comprise another distinctive group of Stephanoconus.