June 2023 – Do wrasse use individual recognition in mate choice and social interactions? This question is currently being explored in a field experiment involving Ben Ellis, Tonje Sørdalen, Anne Berit Skiftesvik, Torkel Larsen, Noan le Goff (B.Sc. student from Université Bretagne Sud), Kim T. Halvorsen and our team. Using our pit-telemetry system on a corkwing wrasse nest colony in Austevoll, we are collecting data, in real-time, on mating interactions at 11 nests simultaneously. All pit-tagged fish are photographed when captured prior to the experiment, allowing us to expose the nesting males to models with photos of strangers (fish from a different island) and familiar fish (those that we know have been recently interacting with the nesting male) and to use cameras to record the male’s behavioral response. We hypothesize that the males will be more aggressive towards stranger females than to females they already have spawned with. In addition to the females, there are a high proportion of sneaker males in this system, which cannot be distinguished from females (at least not by humans), but both sneakers and females have unique facial patterns (Olsen et al 2023), so could it be that males rely on experience and individual recognition when deciding their response to nest visitors – and that they are aggressive to models of familiar sneaker males but not familiar females? A recent lab study demonstrated that tropical wrasse respond more aggressively to photos of strangers than to familiar individuals – does the same apply to our wrasse – in the wild? Such knowledge is valuable for an improved understanding of the importance of individual recognition in mate choice and to what extent it plays a role in maintaining social networks in wild populations. Stay tuned for updates!
