Cleaner Wrasse

Cleaner wrasses are thumb-sized fish with electric blue stripes that swim directly into the mouths of predatory groupers - fish with 700 pounds of bite force designed to crush crustaceans. The grouper freezes, mouth agape, fighting every predatory instinct while the wrasse picks parasites from between those deadly teeth. The cleaning service is worth more than the snack. This is mutualism sustained by reputation and repeat interaction.

Cleaner wrasses operate 'cleaning stations' - specific reef locations where predators return repeatedly. Research shows cleaners inspect an average of 2,297 client fish per day. The system works through enforcement: when cleaners cheat by biting healthy tissue (consuming high-value mucus instead of low-value parasites), clients jolt (physical signal of displeasure) or abandon the station. Cleaners respond by providing better service. Interestingly, cleaners discriminate by client power: when predatory clients (who might eat the cleaner) and non-predatory clients are present, cleaners preferentially service predators first and more carefully.

For business, cleaner wrasses illustrate three principles: reputation systems enforce cooperation through repeat interaction, power imbalances can improve service quality (high-stakes clients get priority), and long-term value beats short-term extraction when relationships repeat indefinitely. The wrasse succeeds not through contracts but through iterated games where both parties know there's always tomorrow. The moment cleaning stations stop being geographically fixed, cooperation collapses - mobility destroys accountability.