Evaluation of wood degradation rates by Teredinidae (Mollusca: Bivalvia) in two ecologically distinct areas, and temperature and salinity influences on the cellulolytic activity of associated bacteria

Abstract

Teredinidae (shipworms) is a family of marine wood-boring bivalves that has an important role in the degradation of wood through its symbiotic relationship with cellulolytic bacteria. To evaluate the rate of degradation of wood by teredinids in two sites with different oceanographic conditions in Rio de Janeiro State, Brazil, artifi cial structures composed of pine wood sheets were immersed in the ocean for three months at Arraial do Cabo in an area under the infl uence of upwelling, and at Ilha Grande Bay under tropical and oligotrophic infl uences. After the immersion period, teredinids were removed from the collectors, identifi ed, and counted. Wood consumption by the teredinids was quantifi ed by comparing the dry weights of the collectors before and after immersion. Associated bacteria were isolated and their cellulolytic activities evaluated at different temperatures and salinities. Two Teredinidae species were recorded: Bankia gouldi and Lyrodus fl oridanus. The highest wood degradation rate and enzymatic activities of the isolated bacterial strains were recorded at Arraial do Cabo, suggesting that upwelling infl uenced the activities of those species.