Speaker: Lucía Pita, Institute of Marine Science (ICM-CSIC), Barcelona, Spain

Topic: Sponge symbiosis: a unique perspective into how microbes shape marine animal ecology and evolution

Symbiosis – “living together” – with microbes contributes to animal ecological success and is a source of evolutionary innovation. The animal host and its microbiota form a functional unit called the “holobiont”, which can be regarded as a miniature ecosystem of complex host-microbe and microbe-microbe interactions that result in new functions. Marine Sponges beautifully illustrate the holobiont concept and its implications to understand animal physiology. Sponges appeared on our planet 600-800 million years ago and, with the help of their microbes, this group still persists today and has conquered (almost) all aquatic habitats. In my talk, I will first introduce the microbial diversity harbored in sponges and how microbial metabolism occurring inside the sponge, coupled with the animal activity, scales up and influences nutrient cycling in the ecosystem. Then, I will focus on our work aiming at revealing the role of sponge immunity as guardian of sponge-microbe interactions. Finally, I will discuss how the holobiont concept has changed our perspective on how marine animals face the environmental stress caused by the climate crisis.