Meeting Abstract
Environmentally transmitted symbioses between bacteria and their animal hosts can be influenced by a number of variables that shape both the distribution and occurrence of each partner, particularly in marine habitats. Factors such as water temperature, salinity, and nutrient availability, while relatively stable, can fluctuate with the mixing of adjoining currents. Sepiolid squids (Cephalopoda:Sepiolidae) form mutualistic associations with bioluminescent bacteria from the genus Vibrio (γ-Proteobacteria: Vibrionaceae). While a multitude of host-mediated factors are important for shaping squid-Vibrio assemblages, their population structure can vary depending on geography and an assortment of abiotic factors. Therefore, we examined the genetic architecture of Euprymna albatrossae and their Vibrio fischeri symbionts in the Philippine archipelago using a combined phylogeographical approach to define whether abiotic factors drive the population dynamics of this mutualism. Diversity measures of symbiont populations within and between sites were highly variable compared to their specific Euprymna host populations, which had less introgression among the samples measured. Additionally, Vibrio populations shared multiple haplotypes across wide geographical ranges. These results indicate that additional factors besides host specificity can contribute to the overall distribution of symbiotic vibrios, leading to a more diverse landscape of host-symbiont assemblages in this beneficial association.
