Abstract

Zooxanthellae of reef-building corals are unicellular dinoflagellates of theSymbiodinium genus, which has an important role in bleaching phenomenon.Symbiodinium and their coral hosts are sensitive to environmental stresses that include salinity, high temperatures, low temperatures, extreme light levels and turbidity. Tidal pools have harsh conditions due to lack of nutrients, food and pronounced changes in physical conditions such as pH, salinity and temperature, hence the study of symbiotic zooxanthellae on coral reefs of tidal pool seems to be necessary. Samples of five coral species that include Siderastrea savignyana,Coscinaraea columna, Anomastrea irregulariis, Cyphastrea serailia, Psammocora superficialis   were collected at intertidal pool of Hengam Island in the northern Persian Gulf. Partial 28S nuclear ribosomal (nr) DNA of Symbiodinium were amplified by polymerase chain reaction (PCR) and then PCR products were analyzed by the phylogenetic analyses of the LSU DNA sequences based on PAUP and Clustal X software. The results showed that there are at least two clades ofSymbiodinium from Hengam Island. Clade D was detected from 3 of the coral species while clade C was found in 2 species only. This study showed dominance of clade D at intertidal pool in Hengam Island and the dominance of clade D might be explained by the high environmental stresses for the Persian Gulf.

Key words: Persian Gulf, clade D, tides, Symbiodinium and Hengam Island.

Abbreviation

 PCR, Polymerase chain reaction; DMSO, dimethyl sulfoxide;EDTA, ethylenediaminetetraacetic acid; nr, nuclear ribosomal; MP, maximum parsimony; BLAST, basic local alignment search tool.