LabHorta: a controlled aquarium system for monitoring physiological characteristics of the hydrothermal vent mussel Bathymodiolus azoricus

Abstract

AbstractColaço, A., Bettencourt, R., Costa, V., Lino, S., Lopes, H., Martins, I., Pires, L., Prieto, C., and Serrão Santos, R. 2011. LabHorta: a controlled aquarium system for monitoring physiological characteristics of the hydrothermal vent mussel Bathymodiolus azoricus. – ICES Journal of Marine Science, 68: 349–356. LabHorta is a facility composed of laboratories and retrievable deep-sea cages created to support and expand the capabilities of research cruises. It also enhances the ability to conduct experimental studies with organisms from deep-sea hydrothermal vents and other deep-sea environments, while keeping them under controlled conditions of pressure and water chemistry. This paper presents a case study with the vent mussel Bathymodiolus azoricus (which harbours a dual symbiosis) collected at the Menez Gwen hydrothermal vent field at 840-m depth, transported to experimental aquaria at atmospheric pressure and maintained under four different controlled experimental conditions to study their comparative condition index (CI). Environmental parameters were monitored daily and efforts were made to keep these constant. During the first few months, there were differences between the CI scores of mussels kept under the various conditions. After 6 months, the differences are not so clear but mussels still had sulphur-oxidizing bacteria when fed with sulphide. The methane oxidizer bacteria disappear even in the presence of methane. A range of CI scores appeared as a function of the culture type. The LabHorta facility is a good tool for performing long-term physiological studies of deep-sea organisms, simulating possible changes in the natural environmental where they normally thrive.