Will blue starfish eat Zoanthid?

Ralph Ritoch · Aug 25, 2019

Yesterdays' emergency was that one of my blue starfish attached to the zoanthid. When I tried to remove it, it pulled a branch of 5 polyps off so I had to attach it as a frag. The starfish is again "attacking" the Zoanthid and I don't know if I should leave it alone or remove it. These starfish also harrass my Flowerpot Corals a little, but mostly end up underneath them. I don't want to get rid of the starfish but they are becoming a nuisance! Everywhere I look it says these things are reef safe but how can that be if they're constantly climbing onto the corals making them retract? Should I do nothing?

Ron Reefman · Aug 25, 2019

A sea star (be PC and don't call them star fish anymore... they aren't fish) climbing over corals and making them retract is perfectly normal and that would not get them listed as not being reef safe. They need to eat corals or do permanent damage to get tagged as not reef safe.

You say blue sea star, but I can think of at least 3 different blue stars, do you know what species it is (or do you have a photo)?

If you are pretty sure yours is actually eating the coral and not eating other things that may also be living on the coral; I'd pull it no matter what it is. But I've also seen a lot of peolpe say this 'whatever' is eating my coral when it was eating the algae, copapods or other tiny animals that live with the coral. And of course the star is going to hang on to the coral, especially if you try to pull it off. That's just normal survival instinct.

My 2 cents worth of advise and understanding.

Ralph Ritoch · Aug 25, 2019

Ron Reefman said:
A sea star (be PC and don't call them star fish anymore... they aren't fish) climbing over corals and making them retract is perfectly normal and that would not get them listed as not being reef safe. They need to eat corals or do permanent damage to get tagged as not reef safe.

You say blue sea star, but I can think of at least 3 different blue stars, do you know what species it is (or do you have a photo)?

If you are pretty sure yours is actually eating the coral and not eating other things that may also be living on the coral; I'd pull it no matter what it is. But I've also seen a lot of peolpe say this 'whatever' is eating my coral when it was eating the algae, copapods or other tiny animals that live with the coral. And of course the star is going to hang on to the coral, especially if you try to pull it off. That's just normal survival instinct.

My 2 cents worth of advise and understanding.

I think you "hit the nail on the head". I inspected the coral for signs of damage and I found something that looked like the head had been eaten, and was hairy. Suddenly it moved and it has tiny little claws. I think its a tiny crab living in the zoanthid that was disturbed by the starfish. As long as the star fish isn't eating the coral I'm OK with it but I'm very suspicious of its activities.

Ralph Ritoch · Aug 25, 2019

Karma exists apparently! Something living inside the Zoanthid is attacking the starfish. There is a tentacle wrapping around the starfish. Could it be a mini octopus? Its diameter is about 0.5mm. I found more, I thought they were just hairs so I ignored them. They look like spiders but have 4 tentacles instead of legs.

Ron Reefman · Aug 25, 2019

A photo would be a huge help. Could be a bobbit worm?

Ralph Ritoch · Aug 25, 2019

Ron Reefman said:
A photo would be a huge help. Could be a bobbit worm?

I have no idea, they are hiding but you can see the legs sticking out. Bottom right of Zoanthid. I tapped on the starfish this morning until it finally let go. There wasn't any damage but the zoanthids wouldn't open while he was there. They are blooming again.

JordanS01 · Aug 25, 2019

Could be mini brittle stars from the looks of it.

Ron Reefman · Aug 26, 2019

It looks like mini stars to me as well, but that's far from a 100% sure ID.

Can you pull the colony of zoas out of the tank and put it in a small bowl of tank water so you can investigate better?

Maybe some others here need to get an eye on this as well. #reefsquad.

hdsoftail1065 · Aug 26, 2019

I agree, they look like brittle stars to me as well.

motortrendz · Aug 26, 2019

Wasnt there another exact post about this last night?

Micro brittle stars...

saltyhog · Aug 26, 2019

Those are brittle stars. Can you post a picture of the blue star?

Ralph Ritoch · Aug 26, 2019

Here is the blue star. Tonight one is harassing the hammer. Apparently these sea stars are active at night.

saltyhog · Aug 26, 2019

That is a blue linckia. They are active at night but larger ones are also active during the day. Very difficult to keep and to meet their nutritional requirements. They do not eat corals, primarily film algae as I understand. Best left to mature tanks.

Mike N · Aug 26, 2019

Ralph Ritoch said:
I have no idea, they are hiding but you can see the legs sticking out. Bottom right of Zoanthid. I tapped on the starfish this morning until it finally let go. There wasn't any damage but the zoanthids wouldn't open while he was there. They are blooming again.

Those are definitely micro brittle stars. I have tons in my tank, and a lot of them do live between zoa polyps.
I've never noticed any ill effects from their presence. The zoas (mine, at least) don't seem bothered by them at all.

Treasure Coast · Aug 26, 2019

Good for your clean up crew, you could also sell them. Very popular here on R2R

Ralph Ritoch · Aug 26, 2019

saltyhog said:
That is a blue linckia. They are active at night but larger ones are also active during the day. Very difficult to keep and to meet their nutritional requirements. They do not eat corals, primarily film algae as I understand. Best left to mature tanks.

There is a lot of algae for these guys! Especially now that I'm doing a lot of extra targeted feeding of the hammer since it is a little bleached. My concern is they are growing fast, I've had them for maybe two months and they are already visibly larger.

JordanS01 · Aug 26, 2019

The blue linckia is reef safe, but depending on the size of the system would waste away over time. No one really knows what they eat but some speculate they eat microbial films or microscopic algae. The hammers would also do fine with less feeding probably, I've never attempted to feed mine and they grow pretty good.

BraxtonF · Aug 26, 2019

The little ones are micro brittles stars and are a great part of any clean up crew

Ralph Ritoch · Aug 27, 2019

JordanS01 said:
The blue linckia is reef safe, but depending on the size of the system would waste away over time. No one really knows what they eat but some speculate they eat microbial films or microscopic algae. The hammers would also do fine with less feeding probably, I've never attempted to feed mine and they grow pretty good.

Luckly for these guys I'm planning in building a larger tank in 4-6 months for them after a home improvement project to make sure the floors can handle the load. I've read they can get over 11" so I honestly have no idea how they'll manage. Here is what I know so far is that they seem to eat intermittently. They spent weeks just stuck to the glass and not moving much so I assume they weren't eating. They then moved under a new coral but lately have been very active. They obviously don't eat algae based on the amount I still have in the tank but from what I know of they are scavengers. These guys seem to be going after the uneaten coral food, coralific delight, and whatever grows in dark places. Either way, they are eating something because they are growing fast.