Punishers Benefit From Third-Party Punishment in Fish

摘要

Human studies show that uninvolved bystanders often pay to punish detectors (1, 2). Such behavior has typically been interpreted in terms of group-level benefits (3) despite theoretical predictions that third-party punishment can yield individual benefits to the pun-isher (4). Here, we show that male cleaner fish, Labroides dimidiatus, punish their female partners if females cheat while inspecting model clients. Punishment promotes female cooperation, yielding direct foraging benefits to the male. This finding demonstrates empirically that third-party punishment can evolve via self-serving tendencies. When servicing clients, cleaners either cooperate by removing ectoparasites or cheat by taking a bite of mucus.