ID?

[Mike P]

Saw this thing on my glass this morning and not sure what it is, was kind hard to get a picture of it because it’s small and clear.

[WV Reefer]

45 minutes ago, Mike P said:

Saw this thing on my glass this morning and not sure what it is, was kind hard to get a picture of it because it’s small and clear.

Hydroid jellyfish. 

[Tired]

Hydroid jellyfish, yep. They hatch from eggs laid by jellyfish. They are not themselves the sort of jellyfish that we think of, but over the course of their lifetime, will bud off a number of tiny jellyfish. You won't be able to raise those without very specialized equipment (and a lot of luck), and they'll very quickly get eaten or sucked into powerheads, but they're neat to watch. And they don't have brains or pain sensors, they're about as aware as corals (and some plants), so they aren't suffering or anything.

Here's a blurry shot of a newly budded-off jellyfish in my tank, about 5 seconds before it swam into my powerhead and got mulched. This one was about a quarter-inch across, and there was another one maybe a fifth of its size. They swim like the fast little jellyfish they are, a cartoonish sort of doot-doot-doot motion.