The mutualistic symbiosis between Vibrio fischeri and the Hawaiian Bobtail Squid is a characteristic model of host-microbe symbiosis and strain diversity in which V. fischeri produce luminescence for the squid. This symbiosis is unique from others in that there are multiple strains of the same bacteria involved. It is not yet known how the diversity that arises from the presence of multiple strains of V. fischeri within the squid contribute to the symbiosis.