NEMO FISHES CAN COUNT STRIPES, SCIENTISTS SAY
Clownfish, aka anemonefish, famous by their distinct white bar patterns seen in Disney’s Finding Nemo, can count up to three, a new study finds.
There around 28 different species of anemonefish know to date, having between 0 to 3 white stripes, which has been suggested to be important for species recognition. In a recent study, researchers found out that in lab conditions, common anemonefish (Amphiprion ocellaris), a species that displays three white bars, when faced with an intruder fish, attacked their own species more frequently than other species of intruding anemonefish.
Recearchers tested how common anemonefish could count number of stripes, and they used orange plastic models with different numbers of bars, and compared whether the frequency of aggressive behavior towards the model differed according to the number of bars. The frequency of aggressive behavior toward the 3-bar model was the same as against living common anemonefishes and was higher than towards any of the other models.
-Plastic models used to measure the aggressive behavior of clown fish. Clownfish could count stripe and shown aggresive behavior following the number of stripe. Photo by Kina Hayashi.
Researchers believe common clowfish count the number of white stripes as a cue to identify and attack only competitors that might use the same anemone where they live, using counting as an important behavior for efficient host defense.
Photo: Gaell Mainguy ·
Reference (Open Access): Hayashi et al., 2024. Counting Nemo: anemonefish Amphiprion ocellaris identify species by number of white bars. Journal of Experimental Biology