Animal colouration is fascinating and it plays a vital role in communication, reproduction and defence. Defensive colouration is particularly intriguing, with some species showing extensive colour variation across their range in response to predation. Whether this variation arises through adaptation or plasticity remains largely unknown however, especially in marine taxa. Our knowledge of colour variation derives mostly from terrestrial systems (e.g. Johansson & Nilsson-Örtman 2013), but this is problematic since the mechanisms driving these patterns in marine environments may differ given their unique ecological and spectral features.
Doris pseudoargus is a cryptic nudibranch found in intertidal and shallow subtidal ecosystems across the European Atlantic and Mediterranean and recently introduced to North America. This species varies in colour from red to white in a continuous way, with multiple colour morphs recovered at both small and large spatial scales. This variation has ignited questions about the mechanisms and processes generating and maintaining this phenotypic diversity, and camouflage more specifically. Doris pseudoargus derives a suite of secondary metabolites from its sponge prey, but how diet might mediate colour pattern in this species remains unknown, as do the genetic underpinnings of these patterns. This project will, for the first time, investigate the ecological and evolutionary origins of continuous colour variation in a polymorphic nudibranch mollusc. Nudibranchs are an ideal system to ask questions about colour pattern evolution given their impressive diversity and the prevalence of aposematism, crypsis and mimicry in this group (e.g. Layton et al. 2018, Layton et al. 2020).
In this PhD, you will collect detailed information about colour pattern and diet in D. pseudoargus through field research, colour pattern analysis and gut content analysis, and you will conduct laboratory experiments in aquaria to determine how diet shapes colour variation. You will also have access to a genomic dataset from populations in the UK and Europe that you will employ for multivariate genome-wide association analyses to determine whether colour varies along environmental gradients and reflects local adaptation. Through this work you will address a key knowledge gap in identifying the drivers of colour variation in this species and in turn improve understanding of how diversity is produced and maintained in the marine environment. We will encourage you to bring your own research interests to this project with the potential to develop the functional genomics, evo-devo or chemical ecology aspects of this work through collaboration within and across schools.
You will be supervised by Dr Kara Layton and Dr Lesley Lancaster in the School of Biological Sciences at the University of Aberdeen and by Dr Sarah Helyar in the School of Biological Sciences at Queen’s University Belfast. You will be based at the University of Aberdeen but you will have the opportunity to visit Queen’s University Belfast and the Marine Laboratory in Portaferry. This is in addition to conducting fieldwork across coastal regions in the UK and Europe and establishing a laboratory experiment in world-class aquarium facilities.
Candidate Background: The candidate is expected to hold, or to achieve a degree in marine biology, zoology, genetics or a related subject. Experience in marine/costal fieldwork, molecular ecology and the statistical software 'R' is essential. Experience in experimental manipulation of molluscs, and genomic data analysis/bioinformatics is desirable.
More project details are available here: https://www.quadrat.ac.uk/quadrat-projects/
How to apply: https://www.quadrat.ac.uk/how-to-apply/