What's going on with my sea urchin?

[JULZ]

I just did a water change and my long spined sea urchin started releasing a white milky substance, is it dying?

[discuspro]

Where is it releasing it on it's body?

[JULZ]

It appears to be coming out of it back side. It's stringy white. It finally stopped and it appears to be ok. Could it be the vemon sac?

[discuspro]

If you are talking about the side that faces outward, not the mouth, that is where it can release reproductive fluid, and also rid itself of waste. With such a water change it could have been thinking it was in a tide pool and began to release reproductive fluid. I tried to look up whether urchins with venom release their venom in that way when stressed but I have not yet been successful in finding an instance of this. Any other fish in the tank? Are they acting different than normal? If the urchin is okay and the fish are okay maybe it was trying to mate. At St. Edward's U one of our honors classes was inducing urchins to release their reproductive fluids with a small electronic charge. They may be more sensitive to conditional changes when they are mature, ready to release this liquid quickly. All in all I could be wrong but I figured I'd say what I was thinking.

[JULZ]

Well this morning the urchin, fish and coral all appear to be doing fine! I'm so glad! yes, it apeared to be releasing it from the outward back side where the waste is also released. In your class, what did the fluid look like? Your theory sounds good to me! I need to do some more research. Know of any good articles on this topic on the web? Thanks so much for your response, I guess everyone else was sleeping while I was having a panic attack over my urchin!

[GaryP]

Julz, it sounds like your urchin just fed your corals for you.