spongy id please

[cordodor]

What are these yellowish sponge-like things? they've popped up all over my tank. they ate up one of my GSP's.

TIA

 

[Jim Hart]

those are bi-valves aren't they?

 

[Herefishyfishy]

sponges... Not aggressive, they seem to pop up in higher load tanks. Doubt it ate your GSP, most lekely you need a water change and better skimmer (Just a guess)

 

[Herefishyfishy]

http://www.wetwebmedia.com/spongeidfaqs.htm

 

[cordodor]

interesting. i have all of 1 fish in my tank at the moment. a damsel that was kind of a tester fish as my 2yr old tank just crashed 2 months ago. (never did really figure out why) This damsel's lived in there for a good month now, so I think he'll make it.

The sponges were in the tank prior to the crash, but they've just flourished as of late it seems. good to know they're not harmful. Thanks for the ID.

the reason i say it ate my gsp is that i had a nice clump of them on a rock and then one of these sponges popped up in the middle of it and the GSPs kind of just deteriorated around it. Very strange.

 

[drummereef]

I agree with Herefishyfishy. Sponges. I'd say the tank crash did the GSP in, not the sponges.

 

[NaH2O]

I agree with the others, that most of the time, sponges are beneficial to your tank. However, the sponges may also have hindered the area of coral around its growth.

From Sponges, Phylum Prorifera, Part 3

Sponges engage in "chemical warfare" as celebrated as the Soft Corals. They should be put out of harms way of all stony corals and provided with growing room around them. Encrusting forms must be provided with a "break" in their substrate to stop them from spreading.