Not so monochromatic: Size-dependency of both sex and color in the cleaner wrasse Labroides dimidiatus

In marine interspecific cleaning mutualisms, small fish known as “cleaners” inspect the surface, gills and sometimes mouth of “client” reef fish, eating ectoparasites, mucus, scales dead or infected tissue. These cleaner species share similar vivid coloration that makes them recognizable by clients. To gain insight on additional communication roles color, we tested if differences in color among wrasse Labroides dimidiatus individuals captured from wild are explained sex, body size parasite loads. We found males were larger, heavier tended to have more saturated blue tails than females. also saturation be positively correlated with size, this size-dependence explains trend for sexes differ color. Parasite loads did not predict individual but our sample heavily parasitized. Other traits (including yellow black brightness) between associated morphological differences. Size-dependence may thus suggest it is a condition-dependent signal could used various types inter- intraspecific social interactions.