Has Anyone Seen These Before?

[dudleyedd]

These guys just appeared in my anemone tank. Some are swimming, some are stuck to glass. Looks like they have 8 appendages and some sort of “head”. Only other occupant besides nems is one clown fish. Tank is 2-3 years old. No new rock added recently.

 

[ISpeakForTheSeas]

Those are hydroid (hydrozoan) medusas, possibly Cladonema sp. I have seen two other threads with similar ones:

Critters in refugium

unsuccessful with Google identifying. The critters are under 1/8”.

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Jellyfish ID help

Hello! Has anybody seen this species of jellyfish before? I’ve been doing a sort of unintentional ecosphere experiment and these things just appeared. There’s probably a couple hundred of them resting on the sand. They seem to jump around randomly.

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