SOME BIOLOGICAL NOTES ON A SHALLOW-WATER VESTIMENTIFERAN TUBE-WORM, LAMELLIBRACHIA SATSUMA
Miura, T.; Nedachi, M. & Hashimoto, J.
United Graduate School of Agricultural Sciences, Kagoshima University, 1-21-24 Korimoto, Kagoshima 890, Japan
Lamellibrachia satsuma, a shallow water vestimentiferan tube-worm, living in Kagoshima Bay at depths of 80-100 m was studied to investigate its micro-distribution and its nutrition. The southern most tube-worm site in the Bay was observed using the deep-sea submersible Shinkai 2000 by the first author. A few large and numerous small bush-like assemblages were seen in a restricted area of about 100 x 200 meters. To investigate the rate of growth of the worms in the field, a staining experiment using a blue stain to mark the tubes was carried out. It was however, not successful because of the high rates of sedimentation in this area obscured the stained tubes. The uptake of hydrogen sulfide was detected in tube-worm specimens living in a public aquarium by a routine water-quality analysis. To elucidate this in the field, we analyzed the sulfur isotopic components of the worm and surrounding waters. In the field, the emitted volcanic gas contained rather heavy sulfide (+17 per thousand in delta 34S) compared with other deep-sea hydrothermal vent systems (0 to +5). The body of tube-worms from Kagoshima Bay, however was composed of very light sulfide (-30). It is highly possible that the production process of hydrogen sulfide used by tube-worms may be unique in Kagoshima Bay and not the same as in other deep-sea vent systems.