Physiological aspects of wood consumption, growth, and reproduction in the shipworm Lyrodus pedicellatus Quatrefages (Bivalvia:Teredinidae)

Abstract

Single specimens of the shipworm Lyrodus pedicellatus Quatrefages (Mollusca, Bivalvia) were grown for 4 months in individual wooden dowels in either phytoplankton free sea water or sea water enriched with the flagellate Isochrysis galbana Parke. Increases in burrow length, tissue dry weight, percent carbon and nitrogen, total wood consumption, larval production, biodeposition, respiration and ammonia excretion were monitored routinely throughout the experiment. No significant differences in measured parameters were observed between the two experimental conditions. Although previous studies showed significant algal 14C incorporation into Lyrodus pedicellatus tissue, a phytoplankton supplement is not required to satisfy dietary needs; however, ingestion of wood alone is not sufficient to account for the carbon and nitrogen levels present in shipworm tissue, larvae and faecal material. No significant quantities of ammonia-N excretion were detected. Shipworms appear to be extremely nitrogen-conservative and may be capable of recycling proteinaceous catabolic end products, via bacterial associations, to augment their dietary input.