MICROBIAL DIVERSITY AND DENSITY IN THE CORAL REEF ENVIRONMENT OF THE GULF OF MANNAR

Abstract

Microbes are important in the coral reef environmen t in the recycling of nutrients and as a source of food to a variety of animal species. They also have an important trophic role to play in the reef environment, goverened by different physico-chemical and biotic factors. The present study has reveale d the presence of more THB (total heterotropic bacter ia) population density in water (5.2 to 22.5 ◊ 10 5 CFUml -1 ) and in the sediments (7 to 24.2 ◊ 10 7 CFUg -1 ) than in the surrounding coastal environments. A total of 24 species of planktonic cyanobacteria and 11 species of benthic cyanobacteria were recorded. Among them, Phormidium tenue was the most dominant species and the families Osc illatoriaceae and Chroococcaceae were predominant in the present study. A total of 35 species of fungi belonging to 20 genera representing the families Labyrinthulomycete s, Oomycetes, Zygomycetes and Deuteromycetes were isolated. Among them, the deuteromycetous fungi formed the bulk of the mycoflora of all the samples at both stations.