neuroecology said, I'm curious what's known about fish now - do they have a PFC/is it enlarged in social fish compared to loners, etc?
David Sumpter said, Just now, not very much. What Kolm and colleagues early work shows is that there are behavioral differences in fish selected for brain size. We would like to go the other way round. But establishing brain differences in social and non-social fish requires us first to have a good distinction of this, before we associate the social differences with brain differences. These social differences what we are working on first.