Using large benthic Foraminifera to identify evolutionary potential of reef-dwelling calcifiers in a changing ocean

Informations

Funding country

Netherlands

Acronym

-

URL

-

Start date

1/22/2018

End date

1/22/2021

Budget

250,000 EUR

Fundings

Abstract

In coral reefs, major ecosystem builders enhance their calcification rates by housing algal symbionts. Species that rely on algal endosymbiosis for survival usually respond negatively to ocean warming, and coral reefs are increasingly threatened by shifts in the world's climate. Levels of genetic diversity within populations of both hosts and symbionts, how these holobionts are distributed in space, and their dispersal capacity are important elements in their responses to climate change. However, the interpretation of biogeographical and evolutionary patterns of morphologically defined species has been challenged by the discovery of intraspecific genetic diversity, often linked with distinct biogeography and ecological adaptation of the host. In this study, I will use reef-dwelling large benthic foraminifera (LBF) as model organisms to capture the mechanisms of evolutionary responses to climate change, such as adaptation and shifts in distribution range. I will analyse: genotypic diversity within widespread morpho-species, how genotypes are distributed among biogeographical regions and shift their distribution ranges; and the role of algal symbionts in facilitating the colonisation of new habitats. LBF are crucial marine calcifiers that rely on algal symbiosis for growth and calcification. Morpho-species of LBF host an array of algal types, and fossil records show that during past events of ocean warming their biogeographic range expanded significantly, dominating shallow carbonate platforms over reef-building corals. It is speculated that the capacity of LBF to host algal types other than the dinoflagellate genus Symbiodinium, which is associated with corals, have conferred LBF the capacity to withstand episodes of warming in the geologic past. Additionally, LBF have short-life spans (3-12 months), and can acquire different types of symbionts at each generational turnover that are more suited to the local environmental conditions. These characteristics make LBF ideal model organisms to study the ecological and evolutionary responses of holobiont systems to climate change.