Research over the past two decades has overturned the assumption that fish are simple creatures with minimal inner lives. Their cognitive complexity demands a serious reconsideration of how we treat them.
A fish that can recognise its own reflection, track social networks, and plan for the future is not a simple reflex machine. These capacities suggest a richer inner life than was assumed. The welfare implications are significant — fish subjected to crowding, poor water quality, and careless slaughter are not experiencing these harms as simple nociception but potentially as something more complex.