Which aquatic animals are trainable?

Several aquatic animals are known to be trainable, including dolphins, sea lions, and certain species of fish like goldfish and wrasses. Dolphins, in particular, are highly intelligent and capable of learning complex behaviors through positive reinforcement. Sea lions can also be trained to perform various tricks and tasks, often seen in marine shows. Fish, while not as commonly trained, can learn simple tasks and respond to cues, demonstrating a level of cognitive ability.