Helianthus Carpet Anemone?

TonysReef · Jul 27, 2019

There doesn't seem to be too much info on the forum about them, but I came across one today and was very tempted. It has only been there for a week, but he said it already went from brown to a slightly drab green with tips that were almost pink/purple. It was also under cheapo LED lights, so I'm sure in my tank it would be more vivid. I've never seen a Merten's before, so the novelty is tempting. And what would you all think this one should be worth (it's maybe 8" across)?

What gave me hesitation was that the guy in the store said that the previous owner brought it in not only because it was eating some of his fish (no surprise), but had also taken at least one clown and a lot of his CUC and that the anemone was absurdly sticky. My harem is still quite young, should I be worried about them if I decide to pick this guy up?

reefsponge · Jul 27, 2019

I would make sure you have a positive ID on this. You can do so by looking at the foot for reddish/purple verrucae going all the way from the foot up the column. Below is a magnifica on top and mertensi below with porcelain crab on it. The foot and column display the reddish/purple verrucae.

They are not nearly as sticky as haddoni in my experience. They can get very large, up to 4’ diameter in the wild. They like to attach their foot to a hard substrate like your rock work. Mine loves flow and light. Seems to be a very hardy nem. Pairing it with a porcelain crab makes for a very cool display.

TonysReef · Jul 27, 2019

reefsponge said:
I would make sure you have a positive ID on this. You can do so by looking at the foot for reddish/purple verrucae going all the way from the foot up the column.

I'm not sure that I did see those to be honest. What else could what I posted have been? Or maybe they just weren't so prevalent. I'll have to go back next weekend and look more closely.

reefsponge · Jul 27, 2019

It’s hard to say without looking at the foot for id. I doubt it’s a gig maybe S. helianthus or Caribbean anemone.

D-Nak · Jul 27, 2019

I don’t think it’s S. mertensii. Looks like S. helianthus, and if so, I’d stay away.

TonysReef · Jul 27, 2019

It does look much more like Stichodactyla helianthus, will take a pass on it. Thanks all. Can a mod change the thread title to Anemone ID? or something.

maevepotter · Jul 27, 2019

Looking at photos of helianthus, I'm not sure how you all are sure. Can you give more details? Incidentally, this led me to an interesting article about the helianthus's ability to possibly cure MS.

The life saving sea anemone

Research into the venom of the Sun anemone (Stichodactyla helianthus) has brought about the discovery of a unique peptide named ShK.

https://venomstodrugs.wordpress.com/future-venom-drugs/ read more here, scroll down to get to it.

illcssd · Jul 27, 2019

Gotta get a look at the foot. If it is a mertens, i had one for 5 years before selling it. Easy to take care of, took up my entire 29g tank in the end. Never ate my fish. It was a similar color to the anemone you posted, not as vibrant though. I'd guess atlantic carpet for this one, as stated above, but if it is a mertens, and that color, it's well worth buying if you have a decent size tank. They're pretty rare to come into the hobby, though not rare in the ocean. Just usually a drab brown so they get passed over by collectors.

OrionN · Jul 28, 2019

It is a S. helianthus, or the Atlantic Sun anemone. Not a host of clown fish. I am glad you did not get him.

maevepotter · Jul 28, 2019

Minh how can you tell? Can you describe what you're looking and saying it looks more like a sun? I'd like to learn more

OrionN · Jul 28, 2019

I posted and deleted it all because OP decided that it is a S. helianthus and did not buy it.

From the picture, it is clearly a S. helianthus because of the shape. Proportionally, of the 4 types of large carpets that we see, Helianthus have the smallest ration of the diameter of the oral plate to foot. Because of this reason, the oral plates rarely fold so Helianthus have a "pillow like" appearance, not folded like the other large carpets . Next is Haddoni, then Gigantea. Mertensii have the largest ratio. Compare to size of the oral plate, Mertensii have tiny foot.

Then the verrucae clearly will give it away. The spots are brown or tan, not colorful like Metentsii or Gigantea. Helianthus verrucae are also in vertical lines; many are elongated vertically not sort of random and round like Mertensii. Once you see all three types of verrucae, there is no mistake about it. Of course Haddoni does not have any.

maevepotter · Jul 28, 2019

Thanks so much Minh! Any chance you have pictures of the different feet and oral disks?

OrionN · Jul 28, 2019

I don’t but I can search online and get example of it later

maevepotter · Jul 28, 2019

Only if you have time. Thanks for the great info!

D-Nak · Jul 28, 2019

For me, one indicator of S. helianthus is the even distribution of tentacles on the oral disc. The others either have rows (such as S. Gigantea) or groupings of tentacles. Then I look for other characteristics that Orion mentioned.