What is this on my hammer?

[olonmv]

Doesn't look like that at all. I'm very excited to find out what it is though, critter id and hitchhikers can be fun. This doesn't look like it can spread, it is attached to the stalk of the hammer and hasn't moved in two weeks. The tentacles are too short to be what is in the picture.

My favorite threads to follow are the hitchhiker critter threads!

 

[Kasrift]

 

[Kasrift]

I moved it closer to the glass, broadcast fed some reef chili, turn off the pumps and then squirted some baby brine shrimp towards it. It definitely reacts to food.

 

[Kasrift]

Here is another video I just took of it as well.

 

[Kasrift]

And one new photo.

 

[Kasrift]

Is each of those little, dot-like things going around the outside an individual tentacle, or do they each have multiple tentacles, or do they all open like little funnels? (I'm assuming the dot like things either are the feeder tentacles or have them on them - is that correct?)

Also, is that big black spot in the middle an opening into the organism (possibly a funnel-like opening)?

If it's a coral, then a Cladocora sp. would be one of my first guesses, but I'm not very well-versed with corals yet. That said, the dots look like little funnels from what I can see (and the big spot looks like it may be an opening too), so I'm wondering if it may be a colonial tunicate species of some kind.

Each of the dots around the edge open like little funnels, and yes they seem like tentacles. They kind of look like the polyps on a pocillapora.

The center seems to be a mouth. It almost looks like a funnel type opening like on a moth.

It seems to have grown some in the last two weeks but it is still small. When I got the coral and did a dip in coralRX two weeks ago I thought it was just a blemish and maybe was a branch to another head of the hammer that was cut off. It looked flatter then and was slimy to the touch. Since then, it has become more pronounced and sticks off the hammer stalk. I'm wondering if I can frag the hammer above this, but I have no experience cutting hammers so any advice would be appreciated.

 

[dedragon]

very interesting indeed, I would try and also remove the bubble algae on the coral if you can (not sure if that came from your tank or SBB, but bubble algae is common)

I wouldnt frag it as it is a bit close to the top and more prone to cracking there

 

[Kasrift]

very interesting indeed, I would try and also remove the bubble algae on the coral if you can (not sure if that came from your tank or SBB, but bubble algae is common)

I wouldnt frag it as it is a bit close to the top and more prone to cracking there

Thanks. Came from SBB. I think my emerald will get to it. I have a couple random pieces, but my emerald does a good job of getting them and if I see a larger one I'll manually remove.

 

[Kasrift]

Side note on the algae piece. I think my tank is pretty clean, I have one stubborn place where hair algae just won't leave and it is on one tiny ledge in high flow. It gets pulled out weekly during water changes and for some reason since it is on a tiny outcrop of rock, snails, urchins, etc just won't go clean it off completely. Anyways, I always assumed coral vendors just ran spotless tanks. I've ordered a couple from online places now and they always seem to come with their own algae. It's not a critique or even the end of the world for me, just an interesting observation. I guess everyone has algae to some degree and balance is the key.

 

[dedragon]

I stop ordering from places if they send me something with bubble algae or aiptasia or something. Shows that they arent inspecting corals that are going out well or running systems that have these problems.
Some places like aquasd I almost expect it based on the fact that they are lower priced and almost certainly cutting up larger colonies when they get in and selling em pretty cheap, but places that are more expensive really shouldnt have those issues imo.

 

[Kasrift]

I stop ordering from places if they send me something with bubble algae or aiptasia or something. Shows that they arent inspecting corals that are going out well or running systems that have these problems.
Some places like aquasd I almost expect it based on the fact that they are lower priced and almost certainly cutting up larger colonies when they get in and selling em pretty cheap, but places that are more expensive really shouldnt have those issues imo.

I get it, but at the same time they are boxing and shipping tons of corals. Like I said, I kind of expect algae in all systems. Aiptasia is a different story. I'd be irked receiving it on a plug from a high end vendor. Not hard to deal with, but another step in the process.

 

[VSVP bet]

following

 

[Rennurdoar]

I get it, but at the same time they are boxing and shipping tons of corals. Like I said, I kind of expect algae in all systems. Aiptasia is a different story. I'd be irked receiving it on a plug from a high end vendor. Not hard to deal with, but another step in the process.

I don't mind algae that much either. But most frags I've gotten in I haven't seen algae on, until after a few days in the tank lol. The thing that gets me, was the Acro eating flatworm I had come off a TSA Toxic candy cane I ordered. That's the type of hitchhiker that I get aggravated with.

 

[ISpeakForTheSeas]

I moved it closer to the glass, broadcast fed some reef chili, turn off the pumps and then squirted some baby brine shrimp towards it. It definitely reacts to food.

So, with the videos I feel relatively confident that this is likely a colonial tunicate of some kind (possibly a Botryllus or Botrylloides sp., but I don't know for certain). If I'm correct, then the little funnels around the outside are the oral siphons (the incurrent siphons - also known as buccal siphons) and the large mouth in the center would be the common cloacal siphon (the shared outcurrent siphon). So, the water would flow in through the oral siphons (then out through the individual zooid - each tunicate in the colony - atrial siphons which are hidden inside the common tunic - which is basically the skin shared by the whole colony) to the common cloaca and out through the common cloacal siphon.

If, this is correct, then the oral siphons are closing defensively (not as a feeding response) during your reef chili feeding. The closing (or "squirting") reaction basically happens when specific cells (called coronal cells) inside the oral siphon register particles in the water being filtered that could potentially harm the tunicate. To prevent harm, the tunicate shuts off the siphon (closes and cuts off the water flow) and contracts to squirt the potentially harmful particles out. So - assuming these are colonial tunicates - the closing would actually be an indication that they are being irritated by the reef chili.

TLDR; I think you have a tunicate colony that dislikes reef chili.

 

[Just John]

I don't know if you're right or not, but you have so many of those fact things and experty sounding stuff that I'll agree.

 

[ISpeakForTheSeas]

I don't know if you're right or not, but you have so many of those fact things and experty sounding stuff that I'll agree.

Haha, yeah sorry - that's part of why I threw in the TLDR at the bottom there. Here are some photos of colonial tunicates with similar body structure (and some with - from what I can tell - similar coloration) to help decide if it is a colonial tunicate:

(The two above images are from here: https://www.mdpi.com/1424-2818/14/11/977 )

And the link below has a bunch more pics (some are different colonial tunicates like above, some are solitary tunicates):

Ascideacea

Ascideacea

www.floridamuseum.ufl.edu

 

[Kasrift]

Haha, yeah sorry - that's part of why I threw in the TLDR at the bottom there. Here are some photos of colonial tunicates with similar body structure (and some with - from what I can tell - similar coloration) to help decide if it is a colonial tunicate:

(The two above images are from here: https://www.mdpi.com/1424-2818/14/11/977 )

And the link below has a bunch more pics (some are different colonial tunicates like above, some are solitary tunicates):

Ascideacea

Ascideacea

www.floridamuseum.ufl.edu

Amazing. Does look like the pictures. So what this mean, should I remove it if I can and place it elsewhere? Does it spread or harm corals?

 

[ISpeakForTheSeas]

Amazing. Does look like the pictures. So what this mean, should I remove it if I can and place it elsewhere? Does it spread or harm corals?

Tunicates are harmless filter feeders, so they won't harm anything in your tank. Whether or not they'll spread depends on the species. Botryllus schlosseri (the Golden Star Tunicates), for example, can be pretty invasive in our tanks, but other tunicates don't spread much at all. To be safe, you might want to see if you can put it on an isolated rock so you can control the spread relatively easily if it happens to be an invasive variety (to my knowledge, which may be flawed here, tunicates usually don't spread over sand, but they'll spread over just about anything else including some algae species).

 

[EeyoreIsMySpiritAnimal]

I don't know if you're right or not, but you have so many of those fact things and experty sounding stuff that I'll agree.

He's the best!!!