hydroids afraid of light?

[CallATT]

Dr.

I am not sure how to identify these things that look like a hydroid or a polyp but contract when I turn my lights on. They stay open at night. I will try and get a pic as soon as I can. But any guesses from this behavior would be helpful. Thanks

[rshimek]

Hi,

Sorry, this behavior is seen in a lot of organisms, and it isn't a cue to any of them (almost all groups have some that do this and others that don't).

So... I will need an image to assist in the identification.

:D