Social Context Affects Camouflage in a Cryptic Fish Species

Crypsis, or the ability to avoid detection and/or recognition, is an important and widespread anti-predator strategy across the animal kingdom. Many animals are able to camouflage themselves by adapting their body colour to the local environment. In particular, rapid changes in body colour are often critical to the survival of cryptic prey which rely on evading detection by predators. This is especially pertinent for animals subject to spatiotemporal variability in their environment, as they must adapt to acute changes in their visual surroundings. However, which features of the local environment are most relevant is not well understood. In particular, little is known about how social context interacts with other environmental stimuli to influence crypsis. Here we use a common cryptic prey animal, the goby (Pseudogobius species 2) to examine how the presence and body colour of conspecifics influences the rate and extent to which gobies change colour. We find that solitary gobies change ...