Fish, like mammals, display intelligence and self-awareness, as evidenced by cleaner fish engaging in a unique behavior. A shrimp drift was observed near a mirror, and a small reef fish tracked it, seemingly curious about the slow-motion experiment. This behavior, known as 'contingency testing', involves animals checking how their real-world movements align with mirror movements. The study, conducted by Osaka Metropolitan University, challenges the traditional mirror self-recognition test, where animals see a mirror for days before being marked. Instead, the team placed a mark on the fish's throat first, then introduced the mirror. The fish showed aggressive behavior towards the reflection, followed by a distinct stage of contingency testing, where they linked their movements to the reflected movements. Interestingly, six out of nine fish attempted to scrape off the throat mark within two hours of mirror exposure, suggesting rapid self-recognition. The study also highlights the complexity of fish behavior, with some fish not scraping within the initial window, and others showing aggression and contingency testing but never scraping. This finding has significant implications for our understanding of animal self-awareness and consciousness, challenging the assumption that long mirror exposure is necessary for self-recognition. The research, published in Scientific Reports, suggests that self-awareness may be more widely prevalent across various taxonomic groups, including fish, and could impact fields such as animal welfare and AI studies.
