Hydroids or something else? 🤔

Introvertedmaniack

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Hello everybody! I've got these little thingies on my live rock and I'm not sure what they are. they haven't really spread at all, nothing else in my tank seems bothered by them in the slightest (my peppermint are quite content to march right over the tops of them), and they've been there for well over a month now so I figure i should ask for some help regarding what they are!

17635408738032766822928260086733.jpg PXL_20251119_081343274.jpg
 
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Introvertedmaniack

Introvertedmaniack

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Given they are grouped together and possibly connected I would guesshydroids or somekind of octocoral (soft coral)
there are multiple clusters around on the rocks but not in good places to photograph. they so also seem to "retract" those little arms when physically disturbed so they are definitely something that can respond to stimulus. i'd have no idea how i've kept them alive for so long since i hear most corals can be pretty finnicky for parameters!
 

Gumbies R Us

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I agree with bristleworm hater here. It’s hard to tell because of the photo, but it’s either and octocoral or hydroids.
 

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there are multiple clusters around on the rocks but not in good places to photograph. they so also seem to "retract" those little arms when physically disturbed so they are definitely something that can respond to stimulus. i'd have no idea how i've kept them alive for so long since i hear most corals can be pretty finnicky for parameters!
Soft corals are not picky, they just need a little bit of nitrate and phosphate and they will take off. Stony corals (corals with a skeleton) are more picky because of the other elements they need to build their skeleton.
 
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Introvertedmaniack

Introvertedmaniack

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Soft corals are not picky, they just need a little bit of nitrate and phosphate and they will take off. Stony corals (corals with a skeleton) are more picky because of the other elements they need to build their skeleton.
I see! I've got some macroalgae that I want primarily sucking up those nutrients but maybe they'll stick around too. I won't be too cut if they die though, I'm not big on corals in my tank personally
 

ISpeakForTheSeas

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Hello everybody! I've got these little thingies on my live rock and I'm not sure what they are. they haven't really spread at all, nothing else in my tank seems bothered by them in the slightest (my peppermint are quite content to march right over the tops of them), and they've been there for well over a month now so I figure i should ask for some help regarding what they are!

17635408738032766822928260086733.jpg PXL_20251119_081343274.jpg
Yeah, I would say some kind of Octocoral (each polyp should have eight of those little arms sticking off around it); some can be very hardy (and sometimes very invasive).
 
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Introvertedmaniack

Introvertedmaniack

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Yeah, I would say some kind of Octocoral (each polyp should have eight of those little arms sticking off around it); some can be very hardy (and sometimes very invasive).
hahaha, this is amazing! I can't ethically or legally keep any cephalopods in a tank in Australia (for good reasons), but knowing i have something called "octocoral" is absolutely fantastic! I did my best to count the arms but i didn't want to put on my reading glasses and the arms blend into the rocks a bit, but every polyp appears to have precisely 8 tentacles! and they must be hardy, they've survived a lot of new tank woes! I hope they become quite prosperous!
according to my brief research, tanks with octospawn need low flow, relatively low light, and pretty normal tank conditions that I already meet, thankfully! finding feeding information has been a bit harder, and buying a dedicated coral food is very unpleasant sounding due to the cost, so i'll keep doing more research and just hope that my phyto soup and ocean snow every 2 days or so will be enough!
thanks so much for your help! and also thank you to everyone else who responded as well if you're reading this! My opinion on keeping corals in my nano tank has suddenly dramatically changed! 😁
 

BristleWormHater

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hahaha, this is amazing! I can't ethically or legally keep any cephalopods in a tank in Australia (for good reasons), but knowing i have something called "octocoral" is absolutely fantastic! I did my best to count the arms but i didn't want to put on my reading glasses and the arms blend into the rocks a bit, but every polyp appears to have precisely 8 tentacles! and they must be hardy, they've survived a lot of new tank woes! I hope they become quite prosperous!
according to my brief research, tanks with octospawn need low flow, relatively low light, and pretty normal tank conditions that I already meet, thankfully! finding feeding information has been a bit harder, and buying a dedicated coral food is very unpleasant sounding due to the cost, so i'll keep doing more research and just hope that my phyto soup and ocean snow every 2 days or so will be enough!
thanks so much for your help! and also thank you to everyone else who responded as well if you're reading this! My opinion on keeping corals in my nano tank has suddenly dramatically changed! 😁
You likely dont need to do anything for it, octo corals will thrive in almost any conditions where nitrate and phosphate are above zero, that is where they become a problem because they grow too fast and will compete with other coral, although that probably won't matter since there arent any other corals in your tank.
 

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