Morphology and phylogeny of Pentapharsodinium jinhaense sp nov. (Dinophyceae) producing a calcareous resting cyst

Abstract

A new species, Pentapharsodinium jinhaense sp. nov., was established by incubating resting cysts, which were collected from trap samples from Jinhae-Masan Bay, Korea. The resting cysts of P. jinhaense were spherical or ovoidal, with a large reddish pigment body and a thick wall covered by numerous needle-shaped calcareous crystals. The size, shape and plate tabulation of motile cells that germinated from the resting cysts were similar to those of Pentapharsodinium tyrrhenicum and Ensiculifera carinata; however, the motile cells had a spine located in the anterior sulcal plate and many pores and spines on the thecal surface. Molecular phylogenetic analysis using internal transcribed spacer and 5.8s rDNA showed that P. jinhaense was closely related to P. tyrrhenicum. Large subunit ribosomal DNA sequences also revealed that P. jinhaense was nested within Pentapharsodinium and formed a strongly supported clade with Pentapharsodinium dalei and P. tyrrhenicum.