Biological Market examples

cleaning mutualisms

Redouan Bshary in his previous life as a primatologist

Cleaner fish – client interactions are good examples of mutualistic interactions between members of different species in which different commodities are traded: the cleaner removes ecto-parasites and the client brings food to the cleane. The supply and demand of both commodities varies over time.

Redouan Bshary concentrated on partner choice as the crucial factor driving markets. He compared interactions of cleaners with 'residents', i.e. clients that had access to only a single cleaning station and 'floaters', i.e. clients that could choose between multiple cleaning stations.

As predicted the floaters were serviced faster and better than the residents.

Thomas Adam (2010) also showed that clients with choice options receive better service than those that don't by studying the interactions of cleaners with a single client species, the ornate butterfly fish.

Zegni Triki and colleagues (2022) experimentally reduced the number of cleaners on one isolated reef. The results were unexpected, but certainly provided more insight in how cleaner markets work.

Other well-studied cleaning mutualisms with cleaning gobies (Soares et al). and cleaner shrimp (Becker et al.) , show both similar and contrasting results.

'Floaters' (or 'visitors') are client fish that range widely and have access to multiple cleaning stations. 'Residents' have small territories and access to only a single 'cleaning station'. Floaters can exert partner choice and play off multiple cleaners against each other, while residents have no choice. As a result, cleaners serve floaters better than residents and residents have to wait when a floater visits the cleaning station.

Key references

last update 4 DEC 2023