Bioluminescence in the Deep-Sea Cirrate Octopod Stauroteuthis syrtensis Verrill (Mollusca: Cephalopoda).

The emission of blue-green bioluminescence ({lambda}max = 470 nm) was observed from sucker-like structures arranged along the length of the arms of the cirrate octopod Stauroteuthis syrtensis. Individual photophores either glowed dimly and continuously or flashed on and off more brightly with a period of 1-2 seconds. Examination of the anatomy and ultrastructure of the photophores confirmed that they are modified suckers. During handling, the photophores were unable to attach to surfaces, suggesting that, unlike typical octopod suckers, they have no adhesive function. The oral position of the photophores and the wavelength of peak emission, coupled with the animals' primary postures, suggests that bioluminescence in S. syrtensis may function as a light lure to attract prey.