I remember you: female Siamese fighting fish recognise prior social partners

Recognising social partners allows individuals to establish social networks with one another, informs mating decisions, and decreases energy expenditure. Studies rarely examine if females have this ability outside of mate choice. Additionally, it is unknown if familiarity differs when females encounter females versus males. Female Siamese fighting fish were placed into one of six treatment groups that differed based on the sex of the interactant (female or male) and experience (familiar, unfamiliar or no previous exposure). In both female-female and female-male interactions, less behaviour was performed towards familiar individuals. However, the degree to which familiarity had an effect differed depending on the sex of the interactant and the behaviour measured. Familiarity may serve an important function if it increases an individual's ability to remember the outcome of prior encounters and use this information in later encounters with the same individual. To fully understand social dynamics, both sexes must be examined.