The spatial pattern of bioluminescent flashes in the polychaete Eusyllis blomstrandi (Annelida)

Abstract

Each of the trunk segments of the polychaete Eusyllis blomstrandi is equipped with paired epidermal luminescent domains. They luminesce upon mechanical or electrical stimulation. Light emission can be rapidly turned on and oV, appears intracellular and is highly coordinated among the trunk segments. Luminescent light is typically emitted in series of Xashes. Light emission in a Xash starts locally in a group of segments and recruits adjacent segments at a rate as fast as ·1 ms/segment. The collapse of light emission at the end of a Xash is almost simultaneous in all of the segments involved. In the intact worm, the luminescent reaction usually involves only a posterior group of segments. Facilitation becomes manifest as the consecutive Xashes in a series increase in brightness and duration and recruit additional anterior segments that were not active in earlier Xashes. The Xash series stops abruptly instead of decreasing asymptotically in brightness. In posterior fragments, all the segments participate in Xashing luminescence, indicating the loss of an inhibitory eVect exerted by the anterior end in the case of whole animals. Posterior fragments survive and are still capable of luminescence weeks after fragmentation although they do not regenerate a head. Immediately upon fragmentation of the worm, the posterior fragment luminesces continuously for some seconds while the anterior part quickly stops light emission.This suggests a decoy and/or a predator-alerting function of prolonged, strong luminescence by the moribund posterior fragment to the beneWt of the survival of the anterior fragment.

Bioluminescence in the Sea

“…orner & Fischer 2007). Such defensive responses are also common in other polychaete lineages, where there is no evidence of a function during mating.…”

Bioluminescent signals spatially amplified by wavelength-specific diffusion through the shell of a marine snail

“…Encounters with high-contact organisms were analogous to high-energy, acute physical disturbance, which is known to trigger light production in other luminous organisms that use bioluminescence for defence [15,45,49], although mechanical stimulation has rarely been reported to trigger light production in luminous snails [20]. The bioluminescence was not expelled in mucous since removing the snail from the luminometer immediately restored light to background levels (figure 4a, 0 snail þ polychaete).…”

Defense through sensory inactivation: sea hare ink reduces sensory and motor responses of spiny lobsters to food odors

“…For example, limb autonomy, in which an appendage is detached and distracts the predator, is found in octopuses and lizards (Arnold, 1994;Bateman and Fleming, 2009). Decoys can also be visual, such as the bioluminescent ink clouds that are released in many marine species, including squid and ostracods, and act as misdirectional cues (Morin, 1983;Morin, 1986;Grober, 1990;Herring, 1990;Bush and Robison, 2007;Zoerner and Fischer, 2007;Haddock et al, 2010). Repellent or deterrent chemicals are commonly used to create startle or escape responses in predators; for example, the spray of skunks (Wood et al, 2002) and bombardier beetles (Eisner et al, 2006;Eisner et al, 2007).…”