Annual spawning of the hydrothermal vent mussel, Bathymodiolus azoricus, under controlled aquarium, conditions at atmospheric pressure

Dense macrofaunal communities of modioliform mussels are a major component of many hydrothermal vent and cold seep ecosystems. The hydrothermal vent mussel Bathymodiolus azoricus, that dominates hydrothermal vent communities near the Azores Triple Junction, can be maintained in aquaria at atmospheric pressure. Cages containing these mussels were placed over diffuse vent outlets and recovered at different times. Cages recovered in January 2003 contained mussels with ripe gonads while those recovered in July, August and November 2001 and in April 2003 did not. Mussels collected post-spawning in April 2003 spawned in the aquaria in January 2004. Young mussels recruited to the cages in April 2003. The data support a main single period of spawning and of juvenile recruitment for B. azoricus.