The taxonomic status of Porites sverdrupi, an endemic coral of the Gulf of California

Porites sverdrupi has long been considered to be an ecotype of the more abundant and widespread species P. panamensis, but multivariate comparisons of corallite characteristics indicate that P. sverdrupi is morphologically distinct and thus represents a valid species. In these analyses, linear measurements and counts were made on 72 colonies of the two species (53 of P. panamensis and 19 of P. sverdrupi), and analyzed multivariately using canonical discriminant analysis. Generally, corallite characteristics of P. sverdrupi are larger in size than P. panamensis. Important characters in the discriminant function (e.g., number of bifurcate septa, wall thickness, and dorsal septum length) have not been recognized in previous studies of Porites in either the Indo-Pacific or Atlantic regions as being significant in distinguishing among poritid species. In addition to corallite characteristics, P. sverdrupi is unique in its ecological habit, colony form, and geographic distribution.