Unknown larvae ?

[islandreefer2]

I assume it is some type of eggs ? No clue thanks for any suggestions.
I have sea snails and some urchins which would be my guess ?

 

[vetteguy53081]

Poriferan sponge on top of pic and spurious worms below
Also harmless, they can get into pump inlets, overflows, etc

 

[WheatToast]

…spurious worms…

You mean Spirorbid worms?

 

[vetteguy53081]

You mean Spirorbid worms?

dang spell check - yes
Spirobid

 

[islandreefer2]

Poriferan sponge on top of pic and spurious worms below
Also harmless, they can get into pump inlets, overflows, etc

Thank you !