"A. fischeri" colonization of the light organ of the Hawaiian Bobtail Squid is currently studied as simple model for mutualistic symbiosis, as it contains only two species and "A. fischeri" can be cultured in a lab and genetically modified. This mutualistic symbiosis functions primarily due to "A. fischeri" bioluminescence. "A. fischeri" colonizes the light organ of the Hawaiian Bobtail Squid and luminesces at night, providing the squid with counter-illumination camouflage, which prevents the squid from casting a shadow on the ocean floor.