Bioluminescence use by crabs?

Hi all,

I have a series of images of this crab with what seems to be some bioluminescent algae on it?

Taken in Lembeh at night.

Any ideas on ID and is this a common behavior?

Thank you

Adam

Unlikely that is bioluminescence, which would be quite weak compared to the light (strobe?) you used for the shot.

Hi Adam,
not sure how many animals are able to see this...
The wavelenghts we use are not for sure the same that animals use....

Have you ever noticed flashy red algae deeper than 6m? Should not be possible, but is there.
Some small fish have red signs that show their gender, but only if you can see the special wavelenght.

Thats a thing i think often....
When you get uv pics of archeological finds, looking great, but did they have the chance to see it, or is it just the combination of materials that looks much better with our technology?

Regards,
Wolfgang

Thank you guys...

@Tursiops: Bioluminescence is defined as "the production and emission of light by a living organism."

This is naturally occurring (I think!) so it must be a form of bioluminescence.

@Trimix125: You are entirely correct about how it may appear to other animals. Bioluminescence is used for "The uses of bioluminescence by animals include counter-illumination camouflage, mimicry of other animals, for example to lure prey, and signalling to other individuals of the same species, such as to attract mates."

If an animal generates red light at depth, it will appear red. The lack of naturally occurring red is due to the color's wavelengths in sunlight being absorbed as it passes through the water column. A red torch's beam still appears red...

Thank you both for your input.

I don't think I made my point very well. Your definition of bioluminescence is not in question. Rather, the production of such light is always quite faint....few photons....so would be unlikely to stand out against the bright light of a strobe. Why is this not just something being illuminated by your strobe? What makes you think it is bioluminescence? Did you see it in the dark, and then just took a picture of the organism producing it?

@Tursiops: Bioluminescence is defined as "the production and emission of light by a living organism."

This is naturally occurring (I think!) so it must be a form of bioluminescence.

@tursiops-That is a good point!

It was definitely glowing, which was why I photographed it!

Adam

Maybe a chunk of a jelly or a siphonophore?

I doubt the crab uses it purposefully....it is just another thing he can plop on his shell so he becomes invisible....