Posted: Mar 24 2011
Stramonita haemastoma canaliculata (Gray, 1839), Hays' Rock-shell
Update: Aug 2011
Ref: Claremont, M., Williams, S. T., Barraclough, T. G., and Reid, D. G. 2011. The geographic scale of speciation in a marine snail with high dispersal potential. Journal of Biogeography U. Biogeogr. 38: 1016-1032.
Referenced paper utilized the Stramonita haemastoma complex of shells to investigate the geographic scale of speciation in a marine snail with a long open ocean larval stage. Although not specifically focused on a comprehensive analysis to ascertain morphological and genetic speciation within the complex, the study did utilize a combination of molecular and morphological methods to establish geographical ranges and reconstruct phylogenetic relationships. As a result, the authors found support for six species within the Stramonita haemastoma complex. A pertinent finding was that, although S. rustica was validated as a species and has a wide range, that range did not include Florida. The authors found that only S. canaliculata and S. floridana occurred in Florida and, contrary to prior findings, these two species occurred on both sides of Florida with the former predominant on the Gulf side and the latter on the Atlantic. Within the Stramonita haemastoma complex of six species, the authors found that only two had a distinctive morphological feature that would distinguish it from the others. The channeled suture found in S. canaliculata was one, and the white aperture of S. rustica was the other.
Since the work reflected in the referenced paper needs to be further substantiated by a more comprehensive sampling and molecular analysis of live-collected material, I have not yet revised my presentation. However, these findings should be kept in mind; esp. regarding the absence of S. rustica in Florida. And, when dealing with a specific Stramonita from the Gulf or Atlantic coasts, if it has a channeled suture, more than likely, it may be S. canaliculata.