Entities › Animals and other organisms › Fish and amphibians

Cleaner wrasse

Labroides dimidiatus

A reef fish that passed a version of the mirror mark test. People disagree about what that shows.

Neurons

No published count

Evidence

• It passed the mirror mark test: it reacted to a coloured mark visible only in its reflection. How to interpret that is debated.
  Kohda M, Hotta T, Takeyama T, Awata S, et al. (2019) If a fish can pass the mark test, what are the implications for consciousness and self-awareness testing in animals? PLoS Biol 17(2):e3000021. doi:10.1371/journal.pbio.3000021.

The New York Declaration on Animal Consciousness (2024) finds at least a realistic possibility of conscious experience in all vertebrates and in many invertebrates, including cephalopods, decapod crustaceans and insects.

Assess it against the published criteria