"You have a tank split in two parts: if the fish gets in the compartment with a red circle, it will receive food, and food will be delivered in the other tank as well. If the fish takes the blue triangle, this fish will receive food, but nothing will be delivered in the other tank. So we have a prosocial choice and antisocial choice. When there is no one in the other part of the tank, the male is choosing randomly. If there is a male, a possible rival: antisocial — almost 100% of the time. Now, if there is his wife — his female, this is a prosocial choice all the time.

"And now a question: Is it just because this is a female or is it just for their female? Well, when they're bringing a new female, it’s the antisocial choice all the time. Now, if there is not the female of the male, it will depend on how long he's been separated from his female. At first it will be antisocial, and after a while he will start to switch to prosocial choices." —Sébastien Moro

In today’s episode, host Luisa Rodriguez speaks to science writer and video blogger Sébastien Moro about the latest research on fish consciousness, intelligence, and potential sentience.

Links to learn more, highlights, and full transcript.

They cover:

• The insane capabilities of fish in tests of memory, learning, and problem-solving.
• Examples of fish that can beat primates on cognitive tests and recognise individual human faces.
• Fishes’ social lives, including pair bonding, “personalities,” cooperation, and cultural transmission.
• Whether fish can experience emotions, and how this is even studied.
• The wild evolutionary innovations of fish, who adapted to thrive in diverse environments from mangroves to the deep sea.
• How some fish have sensory capabilities we can’t even really fathom — like “seeing” electrical fields and colours we can’t perceive.
• Ethical issues raised by evidence that fish may be conscious and experience suffering.
• And plenty more.

Producer: Keiran Harris
Audio engineering: Ben Cordell, Milo McGuire, Simon Monsour, and Dominic Armstrong
Content editing: Luisa Rodriguez, Katy Moore, and Keiran Harris
Transcriptions: Katy Moore