Unknown creature

[karo25]

Could anyone identify what this is an egg of?
They are stuck by one end all over the walls of my sump, even inside the bottom of my skimmer.
They're somewhat soft and wave in the current.

 

[Coralfuture]

Pineapple sponge...harmless

 

[Mr. Bill]

Those are pineapple sponges. They're harmless filter feeders and their population is controlled by the available food.

 

[karo25]

cool ;Cat

 

[Betty1964]

I get a ton of these thing in my overflow about once a year. Then they disappear.