In recent decades, biodiversity loss and climate change have severely affected critical ecosystems such as oyster reefs, which are essential for the stability and functioning of marine environments. In this context, the restoration of European flat oyster Ostrea edulis, a native species recognised by OSPAR (Oslo-Paris Commission) as vulnerable and in decline, is a priority. To enable this, genetic selection and microbiome analysis are emerging as critical strategies for restocking and shellfish aquaculture. The interplay between genetics, environment and the microbiome plays a key role in the health of organisms and can also influence resistance to pathogens and environmental stresses. However, hatchery selection practices, although advanced, have not yet fully integrated knowledge of these complex holobiont systems.

The PhD project aims to explore new ways to develop climate-resilient mollusc lines, focusing on the interaction between production techniques, host, environment, genes and microbiome. Molecular tools will be used to assess genetic parameters and microbiotic dynamics related to traits such as growth, tolerance to environmental stresses (heat waves, variable salinity) and diseases.
The ultimate goal is to contribute to improving our understanding of the relationships between hosts’ genetics and the microbiome, and to integrate this knowledge into hatchery protocols to promote restocking practices and sustainable, resilient aquaculture.

Five publications related to the Research Topic for the candidate interview:

1. Núñez-Pons L, Mazzella V, Pfingsten L, Santoro M. Heterogeneous microbiomes associate with shell-boring Polydora hoplura (Polychaeta, Spionidae) affecting the flat oyster Ostrea edulis. Aquaculture Volume 595, Part 1, 30 January 2025, 741522

2. Gignoux-Wolfsohn S, Garcia Ruiz M, Portugal Barron D, Ruiz G, Lohan K. Bivalve microbiomes are shaped by host species, size, parasite infection, and environment. PeerJ. 2024;12:e18082. Published 2024 Oct 8. https://doi.org/10.7717/peerj.18082

3. Scanes E, Parker LM, Seymour JR, et al. Climate change alters the haemolymph microbiome of oysters. Mar Pollut Bull. 2021;164:111991. https://doi.org/10.1016/j.marpolbul.2021.111991

4. Maneiro V, Santos Y, Pazos AJ, Silva A, Torres-Corral Y, Sánchez JL, et al. Effects of food ration, water flow rate and bacteriological levels of broodstock on the reproductive conditioning of the European Flat Oyster (ostrea edulis, linnaeus 1758). Aquaculture Reports. 2020 Nov;18:100412. DOI: https://doi.org/10.1016/j.aqrep.2020.100412

5. Hesser J, Mueller RS, Langdon C, Schubiger CB. Immunomodulatory effects of a probiotic combination treatment to improve the survival of Pacific oyster (Crassostrea gigas) larvae against infection by Vibrio coralliilyticus. Frontiers in Immunology [Internet].  2024;15. DOI: doi:10.3389/fimmu.2024.1380089

Tutor: Prof. Maria Elena Martino
mail: mariaelena.martino@unipd.it