Adaptation to pH stress by can affect its symbiosis with the Hawaiian bobtail squid ().

Many microorganisms engaged in host-microbe interactions pendulate between a free-living phase and a host-affiliated stage. How adaptation to stress during the free-living phase affects host-microbe associations is unclear and understudied. To explore this topic, the symbiosis between Hawaiian bobtail squid () and the luminous bacterium was leveraged for a microbial experimental evolution study.

Adaptation to temperature stress by Vibrio fischeri facilitates this microbe's symbiosis with the Hawaiian bobtail squid (Euprymna scolopes).

For microorganisms cycling between free-living and host-associated stages, where reproduction occurs in both of these lifestyles, an interesting inquiry is whether adaptation to stress during the free-living stage can impact microbial fitness in the host. To address this topic, the mutualism between the Hawaiian bobtail squid (Euprymna scolopes) and the marine bioluminescent bacterium Vibrio fischeri was utilized. Using microbial experimental evolution, V.