Reconsidering Zoanthus spp. diversity: molecular evidence of conspecifity within four previously presumed species.

We have conducted the first phylogenetic study to our knowledge of Zoanthus in the northern hemisphere by sequencing and analysing the mitochondrial cytochrome oxidase subunit 1 (COI) gene. Various unidentified Zoanthus specimens and samples of what have been assumed to be four discrete species (Z. pacificus, Z. sansibaricus, Z. gnophodes, Z. erythrochloros) were collected from four field sites in Kagoshima Prefecture, Japan. Based on our obtained COI gene sequences, all but one of our collected Zoanthus samples appear to be conspecific, with nearly 100.00% base pair matching. Genetic results are further backed up by collected polyp diameter, tentacle count, and mesentary count data. These results indicate a need to reconsider and re-analyze current Zoanthus classification and identification. Possible reasons for the large morphological variation in the same genotype in Zoanthus are also discussed.