Electroretinograms from Odontosyllis enopla (polychaeta; syllidae): Initial observations on the visual system of the bioluminescent fireworm of Bermuda

In the waters of Bermuda, spawning of the polychaete annelid, Odontosyllis enopla, is intriguing due to the brilliant bioluminescent displays and lunar periodicity characteristic of the mating behavior. At 50–55 minutes after sunset, 2–5 days after the full moon, females become luminescent at the surface and thereby attract males for synchronizing the release of gametes. Previous studies have shown that bioluminescence in this species is maximal in the green portion of the visible spectrum (λmax from 504–507 nm). The eyes of Odontosyllis exhibit maximum ERG amplitudes to green light as well (λ max at around 510–520 nm), as determined by electroretino‐gram recordings made in response to light stimuli at various wavelengths. Color sensitivity in the eyes of Odontosyllis would therefore appear to be appropriate for sensing bioluminescent mating signals. Otherwise, the electroretinogram is a cornea‐negative, monophasic potential of up to 8.0 mV in amplitude. Positive waveforms can be recorded away from the co...