Recently presented at an academic conference in Australia, the research, led by marine scientist Ulrike Siebeck, builds on Siebeck’s own prior investigation into the damselfish’s ability to recognize the shape of ultraviolet patterns that distinguish one fish species from another. A 2010 experiment found that the damselfish relied on its ultraviolet (UV) sight to determine which particular species of fish was intruding on its territory, and thereby whether or not that particular fish’s presence necessitated an attack. When the damselfish were prevented from recognizing the intruding fish’s UV facial pattern, they were effectively blinded, unable to identify their preferred prey.
This new study finds that the damselfish is capable of even more nuanced facial recognition than previously thought, involving not just making distinctions between different species, but between individual fish as well. Captive damselfish were trained to recognize a given UV facial pattern, reinforced by a food reward. When presented with the familiar face and a strange new face, the Ambon damselfish were able to identify the correct fish face with 75 percent accuracy, a pattern that held true even when the faces were those of a similar but different species, the lemon damselfish.
via Mental Floss
Image: GAGLIANO VIA WIKIMEDIA COMMONS