Molecular phylogeny of the benthic dinoflagellate Cabra matta (Dinophyceae) from Okinawa, Japan

Abstract Cabra is a genus of marine heterotrophic thecate dinoflagellates with a peculiar cell shape and thecal plate tabulation. Previous studies suggested it was related to the benthic genus Roscoffia based on morphological features. A previous molecular phylogenetic study using 18S rDNA showed that Roscoffia capitata and members of the family Podolampadaceae formed a well-supported monophyletic group; however, the classification of Cabra remains uncertain. In this study, the first molecular phylogenetic analysis based on 18S rDNA sequence for the genus was performed using specimens of Cabra matta collected in Okinawa, Japan. Molecular phylogeny showed that C. matta formed a clade with R. capitata and the planktonic oceanic members of Podolampadaceae including Podolampas spp. and Blepharocysta sp. This result supported previous studies that inferred the close affinity between Cabra, podolampadaceans and R. capitata based on a very narrow and long 1′ plate, and the diminutive 2′ and 3′ plates, the larger...