Typically, the harbored bacterium is only Photobacterium leiognathi, but in the two ponyfish species Photopectoralis panayensis and Photopectoralis bindus, Photobacterium mandapamensis is also present. Two of the most widely studied uses for luminescence in ponyfish are camouflage by ventral counterillumination and species-specific sexual dimorphism.
Typically, the microorganism living inside these fish is usually Photobacterium leiognathi; however, in specific ponyfish species like Photopectoralis panayensis and Photopectoralis bindus, an additional microorganism, Photobacterium mandapamensis, can also be present. Two of the most widely examined uses of bioluminescence in these fish are camouflage through ventral counterillumination and species-specific sexual differences.