MOVAC · Maintenance of variation in aposematic colouration

Maintenance of variation in aposematic colouration

The research programme outlined in this proposal addresses a key question in evolutionary biology: how diversity in appearance is maintained under natural selection. In particular, the project investigated how colour pattern variation is maintained in species that exhibit warning coloration. This in an especially intriguing area of research because theory predicts that warning signals should look the same in colour and pattern so that they are more easily recognised and avoided by predators. This project investigated this topic using a charismatic polymorphic species of nudibranch mollusc that is common to the coasts of the United Kingdom. Nudibranchs are shell-less marine molluscs with an astounding array of colours and patterns, which they use to either hide from predators (camouflage) or to deter predators by warning them of nasty chemical defenses (warning signals). Nudibranchs are popular spectacles to divers and underwater photographers, yet the anti-predator coloration of this taxon is relatively under-explored. Therefore nudibranchs offer an especially exciting avenue for future research. The results of this project support the hypothesis that morphs of P. quadrilineata use different modes of protective coloration. While both morphs are camouflaged against natural backgrounds in terms of coloration, they each use different forms of aposematic patterns depending on context. In particular, the dark morph relies distance-dependant aposematism, while the light morph is more traditionally aposematic, with luminance contrast that is visible from a greater distance. Both morphs were equally well defended in terms of their chemical defences against fish predators. There were no differences between morphs in terms of in microhabitat association in the wild or behavioural choice between bryozoan / algae combinations. Diet did not seem to play a role in the development of dark pigmentation in juveniles, suggesting the polymorphism is genetically determined. The results of this research project can be used to inform and shape future theoretical models, which are be applicable to a range of ecological and evolutionary processes. The programme has draw attention to a fascinating and unique species, generating international interest and bringing new insight into Europe's coastal ecosystems.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз