Samantha Horton

Inter-specific cooperative relationships are important in the behaviour of a variety of animals and often involve a mutually beneficial interaction. This study assessed the behavioural pattern known as ‘advertising’ in the bluestreak cleaner wrasse (Labroides dimidiatus) that remove ectoparasites from other species around Hoga Island, Indonesia. Advertising is the rocking dance that the cleaner performs, which may advertise their services to client fish. The ecological and behavioural factors influencing this behaviour have never been studied despite being of great importance in cleaning interactions. The factors assessed in the present study determined what effects time of day, location, reef position, life stage, client number, client size and interaction duration, had on advertising duration. The significant factors in determining advertising duration were that of life stage, where juveniles advertised significantly more than their adult counterparts (Mann–Whitney U-test: U = 7, p ≤ 0.01, N₁ = 96, N₂ = 96); and reef location (Mann–Whitney U-test: U = 2964.5, p ≤ 0.01, N₁ = 96, N₂ = 96) where cleaning stations on the reef crest exhibited less advertising than on the flat areas for both life stages. Juveniles are likely to advertise more due to the decreased client size and number seen at the juveniles’ stations, as well as the presence of mimics. Reef location is important as the reef crest allows more access to transient clients, hence a reduction in advertising duration. Life stage and location should be explored in future studies as significant factors in the behavioural ecology of cleaner–client interactions.