Study finds bluestreak cleaner wrasse fish assess body size using mirrors prior to fights, showing potential self-awareness.

A study from Osaka Metropolitan University reveals that bluestreak cleaner wrasse fish assess their body size using mirrors before engaging in fights. This behavior indicates a form of self-awareness, as the fish appear to recognize their reflection and make decisions based on size comparisons. The findings contribute to understanding the evolution of self-awareness in non-human animals, suggesting parallels with human cognition.