Spatial variation of symbiotic Dinoflagellates on coral reefs of the northern Persian Gulf

Abstract

Density, mitotic index, Chlorophyll-a content and cell size of symbiotic dinoflagellates of dominant reef-building corals were measured at two different depths in Kish Island and from one depth of Larak Island in the Persian Gulf. The higher densities of symbionts were found in shallow waters of Kish Island. However, ANOVA analyses of the mitotic index yielded mixed results. The cell sizes of symbionts did not significantly differ among depths, except for Porites corals at one site in Kish Island which displayed the larger cells in deeper water. The comparison of symbiont attributes between islands exhibited intraspecific variability. Density of zooxanthellae was only different in Porites and Favia corals between islands. Chlorophyll-a density (cm-2) was significantly different between islands in all species, with higher values for Kish corals. Chlorophyll a cell-1 was only significantly different in Porites and Platygyra corals, with higher values for Larak Island. The symbiont cell sizes usually exhibited no variability, except for Porites corals with larger sizes in Kish Island.