• Cleaner wrasse show self awareness in stunning mirror experiments These tiny reef fish may be far more self-aware than anyone imagined. • Scientists at Osaka Metropolitan University in Japan have identified a newly documented behavior in cleaner wrasse (Labroides dimidiatus). • When the small reef fish were given access to a mirror, they did more than simply recognize their reflections. • They also began experimenting with the mirror using bits of food. • The findings suggest these highly social fish are capable of a sophisticated cognitive process known as ‘contingency testing,’ a level of intelligence more commonly associated with marine mammals such as dolphins. • The research team was led by Specially Appointed Researcher Shumpei Sogawa and Specially Appointed Professor Masanori Kohda at the Graduate School of Science.

Article Summaries:

  • Cleaner wrasse (Labroides dimidiatus) have demonstrated advanced self‑awareness in new mirror‑test experiments conducted by Osaka Metropolitan University. Researchers first marked the fish with parasite‑like spots, then introduced a mirror. The fish quickly used the reflection to locate and scrape off the marks-often within an hour-much faster than in previous studies. After several days, some wrasse also dropped shrimp near the mirror, tracking the shrimp’s reflected movement and repeatedly touching the glass, a form of “contingency testing.” These findings suggest that self‑recognition and exploratory cognition may extend beyond mammals to highly social reef fish.
  • Cleaner wrasse show self awareness in stunning mirror experiments These tiny reef fish may be far more self-aware than anyone imagined. - Date: - February 23, 2026 - Source: - Osaka Metropolitan University - Summary: - Cleaner wrasse have revealed a remarkable new side of fish intelligence. Marked with fake parasites, they used mirrors to inspect and remove the spotsâfar faster than seen in earlier tests. Even more striking, some fish dropped shrimp in front of the mirror to watch how its reflection moved, a form of exploratory âcontingency testing.â The findings suggest self-awareness may ext

Sources: