The pyloric caeca and posterior intestine of Howella brodiei are bioluminescent, and are associated with internal reflective tissues. The bioluminescence is not bacterial in origin. Unlike that of several shallow water apogonids, it does not depend upon Vargula luciferin. Florenciella lugubris has bioluminescent oesophageal diverticula and is able to eject a pulse of luminescent material from beneath the operculum. The luminescence of the two species is compared with that of other perciform fishes.