Caribbean Cleaning Gobies Prefer Client Ectoparasites Over Mucus

Abstract

If cooperation often involves investment, then what specific conditions prevent selection from acting on cheaters that do not invest? The mutualism between the Indo‐Pacific cleaner wrasse Labroides dimidiatus and its reef fish clients has been a model system to study conflicts of interest and their resolution. These cleaners prefer client mucus over ectoparasites – that is, they prefer to cheat – but punishment and partner switching by clients enforce cooperative behaviour by cleaners. By contrast, clients of Caribbean cleaning gobies (Elacatinus spp.) do not to use punishment or partner switching. Here, we test the hypothesis that the behavioural differences between these two cleaner fish systems are caused by differences in cleaner foraging preferences. In foraging choice experiments, we offered broadstripe cleaning gobies Elacatinus prochilos client‐derived parasitic isopods, client mucus and a control food item. The cleaning gobies significantly preferred ectoparasites over mucus or the control item, which contrasts with cleaner wrasses. We propose that the low level of cleaner–client conflict arising from cleaning goby foraging preferences explains the observed lack of strategic partner control behaviour in the clients of cleaning gobies.

Mutualistic cleaner fish maintains high escape performance despite privileged relationship with predators

“…Unlike L. dimidiatus, Elacatinus spp. are not tempted to cheat because they prefer eating ectoparasites over mucus [59], and clients do not use punishment to enforce cooperation [60]. Since Elacatinus spp.…”

Scaling patterns inform ontogenetic transitions away from cleaning in Thalassoma wrasses

“…This behavior has been observed in several species including Labroides cleaner wrasses, as well as Elacatinus cleaner gobies (Gorlick, 1980;Grutter, 1997;Bshary and Grutter, 2002;Grutter and Bshary, 2004;Soares et al, 2009;Soares et al, 2010). Notably, in both of these clades, cleaners are described as 'obligate', indicating that they obtain, on average, 85% of dietary items through cleaning (Côté, 2000).…”

Power and temptation cause shifts between exploitation and cooperation in a cleaner wrasse mutualism

“…We predict that cleaner wrasse L. dimidiatus are indeed specifically adapted to this problem, because it is very likely to be rare in nature that an animal faces this problem. Even cleaning gobies can focus on eating preferred food as they prefer fish ectoparasites over mucus [58], which probably applies to most facultative cleaner fish species as well [59]. As it stands, the cleaner wrasse L. dimidiatus shows strategic abilities adapted to interactions with clients that are absent in primates [60], despite the general importance of cooperation in primates' social life [61,62].…”