An Osaka Metropolitan University-led research group has found that bluestreak cleaner wrasse have some level of self-awareness, as they checked their body size in a mirror before deciding whether to attack fish that were slightly larger or smaller than themselves. This study, published in Scientific Reports, is believed to be the first time a non-human animal has been demonstrated to possess mental states such as a mental body image, standards, intentions, and goals, which are elements of private self-awareness. The team, which included researchers from the University of Neuchâtel in Switzerland, had previously reported that the cleaner wrasse could recognize photographs of itself based on its face through mirror self-recognition.
The researchers observed that the cleaner wrasse showed a behavior of going to look in the mirror installed in their tank when necessary, indicating that they may be using the mirror to check their own body size against that of other fish and predict the outcome of fights. This suggests that the fish are capable of using the mirror as a tool to assess themselves in comparison to others. According to Taiga Kobayashi, a doctoral candidate at OMU Graduate School of Science, these results support the idea that fish can exhibit self-awareness, which raises questions about the similarities between human and non-human animal self-awareness and how self-awareness has evolved.
The study was supported financially by JST SPRING, JSPS KAKENHI, the Swiss Science Foundation, and an OCU Strategic Research Grant. The findings of this study have important implications for understanding the cognitive abilities and behaviors of non-human animals, particularly fish. By demonstrating that cleaner wrasse have some level of self-awareness and can use a mirror as a tool to assess themselves and predict the outcomes of interactions with other fish, the research highlights the complex cognitive abilities of these animals and provides insight into the evolution of self-awareness across different species.
The implications of this study suggest that fish, and potentially other non-human animals, may possess cognitive abilities and self-awareness that were previously not fully understood or recognized. By studying the behavior of cleaner wrasse in relation to a mirror, researchers have been able to shed light on the mental states and self-awareness of these animals, which could have implications for how we understand and interact with other species. The use of mirrors as a tool for self-assessment and prediction of social interactions in fish could also have broader implications for our understanding of animal behavior and cognition.
The research also emphasizes the importance of considering the similarities and differences between human and non-human animal cognition, as well as the evolution of self-awareness across different species. By studying how cleaner wrasse use mirrors to assess themselves and predict outcomes in social interactions, researchers have gained valuable insights into the cognitive abilities and behaviors of these animals. This study opens up new avenues for further research into self-awareness and cognition in non-human animals, as well as the potential implications for our understanding of animal intelligence and behavior.