Bioluminescence: dual mechanism in a planktonic tunicate produces brilliant surface display

Luminescent flashes emanate spontaneously and on mechanical stimulation from the bodies of Oikopleura dioica (Urochordata, Larvacea); flashes also emanate, on mechanical stimulation only, from both their occupied and discarded mucous houses. The luminescence is intrinsic to the animals and their houses. Field observations suggest that, because of this dual method of light production, larvaceans may contribute substantially to surface coastal displays of marine bioluminescence.