Polypless Star Polyps?

[JerryJ]

Can star polyp coral survive without the polyps? I have a patch of purple coral, identified for me by this forum as green star polyp. It had a about a dozen polyps growing out of the rubbery purple material. This morning I purchased an algae cleaning crew for this new FOWLR tank and now only one of the polyps (a tiny one) is visible. Every other day, the polyps have emerged promptly when I put on the lights, so I think they've been nipped off. The algae crew I got includes a very hungry Sally Lightfoot crab who's been crawling all over the live rock, so I think I know what happened to the polyps. Assuming I'm right, and the coral won't be able to grow polyps while the crab is around, does this mean the coral will die? I know it's primarily photosynthetic...does the photosynthesis occur in the purple "body" of the coral, or in the green polyps? I assume the polyps gather some food material; is this essential or can the coral live without it? Thanks for any info!

[Coral Hind]

The polyps are probably just retracted inside, out of sight, because they were disturbed by the crabs or snails. Give it a day or so to see if they come out or not. The polyp is where the photosynthesis takes place.

[JerryJ]

Coral Hind, thanks for sharing your opinion, but it's been half a day now since I've seen the polyps, so I do believe they were crab food. That is the most voracious creature I've ever seen...when I put him in the tank he started shoveling algae into his mouth, literally the minute he touched down on the live rock. I have two emerald crabs too, but they seem more laid back. The Sally Lightfoot is such an eating machine, I'm wondering about my plan to stock the tank with little gobies, cleaner shrimp, etc. But at least the live rock is really clean!

[Coral Hind]

They could indeed be crab food. I can't see the coral so I can only share advice with the info I am given. I do know that without enough food (algae) they will find other food such as your planned small fish or as you have witnessed soft corals. I have read a few threads where they have captured small fish and even had soft corals as a meal. I personally no longer keep any crabs in my tank.

[JerryJ]

Well, Coral Hind was right after all. The polyps came out today. I guess they were freaked out by the addition of the crab, as suggested, and I can't blame them. That crab scares me too.

[Coral Hind]

I'm glad they finally came out for you!

 

 

[JerryJ]

Thanks...I'm sorry to say I removed about half the polyps myself last week, before you informed me that they weren't hydroids. So I've done a lot more damage than the crab. We'll see how things progress.