Nocifensive behavior as evidence for sentient pain in fish

Fish nocifensive behavior can be studied and understood similarly to the way pain is studied and understood in more advanced vertebrates. Nocifensive behavior is a behavioral and physiological response to a noxious stimulus that leads to the fish avoiding it in the future. This behavioral flexibility is an important criterion for inferring pain sentience in fish. Modulation of the nocifensive behavior by anxiety, fear, or stress has already been demonstrated in zebrafish. The affective experiences of fish will not be identical to those of human beings, clearly. Empirical research will need to ascertain how similar they are.