What are these guys?

[SaracensRugby]

Ok, I don’t think these are vermetid snails, but haven’t seen these before. They are giving off a long stringy thing, presumably to try and catch food for themselves.
Got some live rock from a company that sources rock in the ocean, that’s only way these came in as rest of rock was dead/bleached. Any help on ID is appreciated. I was able to squish them easily with tweezers.
cheers.

 

[Bfragale]

Hard to see but it does look like vermetid snails. Is the shells hard? They should have hard tube like shells that are spiral at the base. You need to break off at the base to get the snail. You can also fill the tube with superglue as well.
Good luck and happy reefing

 

[WheatToast]

Benthic ctenophores, a type of comb jelly. From what I have read, they are predominantly harmless filter-feeders, though may grow over corals:
https://www.reef2reef.com/threads/white-stringy-things.773728/

 

[RiptideAquaculture]

I could be wrong but it looks like some kind of stress slim for the starfish that is being caused by Planaria.

 

[WheatToast]

I could be wrong but it looks like some kind of stress slim for the starfish that is being caused by Planaria.

Image was taken from a Wikipedia page on benthic ctenophores, but they do look surprisingly similar to flatworms:

 

[SaracensRugby]

Thanks all. I will try manual removal as I see them. Always something in this hobby. Do you think flatworm Exit would kill these similar to flatworms?

 

[RiptideAquaculture]

Image was taken from a Wikipedia page on benthic ctenophores, but they do look surprisingly similar to flatworms:

man you had me hunting the internet for some crazy starfish eating thing. looks a ton like a flatworm
.

 

[Eagle_Steve]

Thanks all. I will try manual removal as I see them. Always something in this hobby. Do you think flatworm Exit would kill these similar to flatworms?

Usually with filter feeders, upping flow and reducing food will make quick work of them.

Not sure what you have in the tank now, but if no corals at this point, just limit food and point powerheads at them. This will cause the to retract, as the flow will be too much and they will not be able to capture food if it does float by.

 

[SaracensRugby]

Thanks, will get the MP60s hooked up and blowing around.
No corals right now, tank just started (315 gallons, 450 total water volume) and had to take all of the fish out due to a fun case of brook from 10 anthias I picked up. Now down to 1 anthia. Going to wait a couple months to add corals as I get through the ugly phases, got some pink urchins from the live rock I got so will let them go to town for a while.

 

[SaracensRugby]

I got a few mollies in there after my fallow period, double checking my system for bugs now that I have been burned. They will not like the updated flow, they are already being blown around with the two returns and the 1 MP40 going.

 

[SaracensRugby]

Slurped some of them out. Orange type things. Does this change diagnosis?

 

[Eagle_Steve]

Slurped some of them out. Orange type things. Does this change diagnosis?

Does not appear so. If you can remove, then go that route. From what I read about them, is that they are mobile, so removal is possible.

 

[SaracensRugby]

Great, thanks. They seem to be mobile, and easy to slurp up with a turkey baster. Hope I can keep up with this, or find a wrasse that east them.

 

[Eagle_Steve]

Great, thanks. They seem to be mobile, and easy to slurp up with a turkey baster. Hope I can keep up with this, or find a wrasse that east them.

With the tank being fishless right now, so to speak, there is a good chance they will not make it long. No food means no life lol.