DESCRIZIONE
A housing system for aquatic animals has a shelf-like rack holding tiers of individual tanks or aquariums (aquaria), each removably suspended from structural members that engage flanges of the tanks. The tanks are tilted inwardly of the rack and have covers with fittings on the higher or outer side, that intercept flow between a supply and a drain to inlet water when the tank is in the rack and to recycle the water at any tank position that is unoccupied. The inside bottom of each tank is contoured, for example with a longitudinal trough, so sediment collects at a low spot on the lower or inner side, where a drain inlet is placed to provide a drainage outlet that opens at a velocity increasing restriction at which sediment is entrained. The drain has a spring biased valve that opens the drain only when the tank is fully inserted in the rack. Water supply, water drain and air supply conduits are integrated using an extrusion or multiple passage conduit for air supply, water supply and water return at the interception point of the tank water inlet. The housing system is apt for zebrafish for laboratory experimentation.