Size Differences in Personality Profiles of the Cunner Wrasse (Tautogolabrus adspersus)

Individual animals, including fish, often differ consistently in their behaviours, which is known as personality. An individual’s values on the five axes of personality, which are activity, aggression, anxiety, boldness, and sociality, come together and form syndromes. The major syndromes, proactive or reactive, characterize an individual’s expected behaviour. The cunner wrasse, (Tautogolabrus adspersus), is the only warm-water cleaner fish for removal of sea lice from Atlantic salmon in Eastern Canada. Developing behavioural assay of the syndromes is important for industry to use to improve aquaculture because they are linked to species’ growth, cleaning efficiency, and welfare. I explored if the proactive and reactive syndromes exist in cunners and how their size influences the syndromes. The research was conducted with different sizes of cunners (n=43) in the Hagen Aqualab for three months, starting from January 2020. An open field test, scoring anxiety, and a swimming test, scoring activity, were conducted, followed by a mirror test measuring sociality and aggression. Then, a replica test was conducted to score boldness, followed by a novel object test also measuring boldness. Then, a shelter-seeking test was conducted to score anxiety. I found that cunners of all size-classes showed proactivity and reactivity. However, there was a significant difference in which components of the five axes of personality determined the two syndromes between large and small-medium cunners. These findings may develop a behavioural assay for industry to use when they breed cleaner fish to use for their desired traits, such as better growth and higher cleaning efficiency.