Associative-mesofauna abundance and its correlation with sponges antibacterial activity in seagrass ecosystem

Abstract

Sponge is one of the benthic organisms that could be found in seagrass ecosystem. Sponge is also could harbor various organisms within its tissue, as a biogenic habitat for those associative organisms. This interaction could benefit from enhancing marine biodiversity in the seagrass ecosystem. Aims of this research were study the abundance of associative mesofauna and its correlation with the sponges antibacterial activity. Sponges samples were preserved in 70% ethyl alcohol (0.5-1 cm3 thickness) and observed under stereomicroscope, to find the associative mesofauna. Meanwhile fresh tissue samples were tested against several pathogenic bacteria in antibacterial assay. Associative mesofauna that was found in 14 of 23 seagrass sponge species, belong to Ophiuridae, Mollusca, Gastropoda, Arthropoda, Polychaeta, and Oligochaeta groups. Mollusca and Polychaeta were highly correlated with most of the sponge species (8 of 14), based on statistical correspondence analysis (CA). Antibacterial assay on sponge tissue showed that only 6 of 14 sponge species has activity against several pathogenic bacteria. Statistical analysis (CA) showed that Mollusca and Polychaeta also have high correlation with the antibacterial activity. This suspected that sponges defense mechanism strategy against pathogenic bacterial infections, could influence the preference of associative mesofauna inhabiting seagrass sponges.