Exploring the Effects of Changing Climates on Symbiosis Establishment in the Bobtail Squid

Symbioses allow many organisms to overcome challenges faced in their natural environments. Rapidly changing global climates have put great strains on such symbiosis relationships. The Hawaiian Bobtail Squid Euprymna scolopes is one such organism, which has co-evolved with the bioluminescent bacteria Vibrio fischeri. Vibrio provide squid with a light-source with which they can perform counter-illumination, a process enabling the squid to camouflage itself from potential predators. Crucially, juvenile squid must be colonised by symbionts in the first hours after they hatch for this relationship to form. One key step in this process is mediated by internal fluid-structure interactions within scolopes. By utilising their respiration, ciliated surfaces, and internal geometry squid are able to process bacteria carried in these flows. Notably, this enables the selective capture of bacteria using a specialised light organ, and filters out any unwanted particles and bacteria. Using the Method of Regularised Stokeslets, and motivated by experimental observations, we have been able to simulate these flows. Furthermore, we have explored the impacts of temperature stress on the resulting flow fields as mediated by the parameters that underpin these flows.