Image scoring and cooperation in a cleaner fish mutualism

Altruism in insect societies and beyond: voluntary or enforced?

“…For example, the cleaner fish Labroides dimidiatus eats ectoparasites on its client reef fish but could also cheat by eating client tissue or mucus. Clients use three different mechanisms to enforce cooperation: (i) they avoid cleaners that have been observed cheating (partner choice); (ii) they switch to other cleaners (partner switching); and (iii) they aggressively chase uncooperative cleaners (punishment) [63,64]. After such punishment, cleaner fish act more cooperatively and are less likely to feed on mucus [63,64].…”

“…Clients use three different mechanisms to enforce cooperation: (i) they avoid cleaners that have been observed cheating (partner choice); (ii) they switch to other cleaners (partner switching); and (iii) they aggressively chase uncooperative cleaners (punishment) [63,64]. After such punishment, cleaner fish act more cooperatively and are less likely to feed on mucus [63,64]. Similar examples occur in the mutualisms between yucca plants and their yucca moth pollinators [53,54] and between legume plants and nitrogen-fixing bacteria, in which plants sanction bacteria that fail to fix nitrogen by cutting resources to root nodules containing such bacteria [55].…”

Do cleaner fish learn to feed against their preference in a reverse reward contingency task?

“…Therefore, they needed to swim away from the more attractive item and approach the less attractive item in order to solve the task. This subtle but perhaps important diVerence might explain why cleaners largely failed in the reverse reward contingency task, while they can easily learn to feed on a non preferred food item from a plate when a preferred item is present on the same plate in 1 cm distance (Bshary and Grutter 2005;Bshary and Grutter 2006). In these earlier experiments, each subject was allowed to continue to feed on a plate with two types of food as long as it continued to feed on the non-preferred item (Xakes).…”

“…biting) cleaners by leaving the cleaning station or attacking (punishing) the cleaner (Bshary and Grutter 2002a;Bshary and SchäVer 2002), cleaners adjust their behaviour and feed on the parasites they obtain from clients (Grutter 1996;Bshary and Grutter 2002b). Several laboratory experiments show that cleaners can easily learn to feed against their preference if this allows them to continue with foraging (Bshary and Grutter 2005;Bshary and Grutter 2006). This foraging behaviour results in a cooperative interaction under natural conditions.…”

Cooperation theory of cooperative breeding

“…Recent experiments demonstrated indirect reciprocity within species in humans (Wedekind and Milinski, 2000), and Norway rats (Spahni, 2005), and between species in cleaner fish and their clients (Bshary and Grutter, 2006; see also Bshary, 2002). The classification scheme proposed by Bergmüller et al (2007) has not included generalized reciprocity (Rutte, 2004;Pfeiffer et al, 2005;Hamilton and Taborsky, 2005), where individuals prefer to cooperate with others based on anonymous social experience.…”