Another ID Question

[mmcdade]

Any idea what this is? They are ~2-4mm long and there are lots of them. They seem to favor darker areas under arches in the rock, etc.

 

[Thereefgallery]

Pineapple Sponge. Harmless filter feeder.

 

[ISpeakForTheSeas]

Pineapple sponges - harmless filter feeders; they tend to boom then bust in population before going away on their own.

 

[EeyoreIsMySpiritAnimal]

These may be helpful.

What is that!! A R2R guide to common new tank hitchhikers.

One of the greatest things about starting a reef tank is getting your live rock in and admiring all the diversity within it. The rock comes to life different creatures. This is a guide that I, along with a very well known critter identifier @KJ , have put together for the new reefer on what...

www.reef2reef.com

Guide to Common Hitchhikers in reef tanks.

The purpose of this thread is to hopefully assist hobbyists in obtaining the correct id and method of treatment to common hitchhikers. Both; the good ones and the bad ones. 1) Anemones: Some times called the flowers of the sea, many hobbyists keep them intentionally for their striking colors...

www.reef2reef.com

 

[mmcdade]

Pineapple Sponge. Harmless filter feeder.

Thank you!

 

[Reefkeepers Archive]

Any idea what this is? They are ~2-4mm long and there are lots of them. They seem to favor darker areas under arches in the rock, etc.

Pineapple sponge