Ten fish have made a bid for freedom after outgrowing their display tank at Underwater World in Hastings.
The ten bass have been released into the sea off Hastings
The bass, which weigh between 10lb and 14lb (4.5-6.4kg) were released into the wild off the Sussex coast on Monday.
Head aquarist Dan Davies said they were released at Rock-A-Nore beach in time to catch the outgoing tide.
He said they were all checked by a vet before the release and fed on a high-quality diet to give them a head start and better chance of survival.
Space for cuttlefish
"It's nice to be able to release these fish back to sea so they may breed within their natural habitat.
"This is an ideal time of year for us to be releasing them, as it is the start of their annual spawning season," he said.
They had been kept at the aquarium since 2000,
Space gained at the centre by releasing the fish is to be used to set up a cuttlefish project.