Star Fish Disinigrating

[shamrock]

Hi all,
I am having an issue with my sea stars. We currenly have 5: 1pink choc chip, 1 brown choc chip, 1 red african sea star, 1 greenish one (dont know the kind) and a yellowish one. My problem is that a couple of them look like they are disinigrating. We lost one the other day and now 2 more are showing the same signs. The legs are white and hard and it looks like they are disinigrating. The one that died a couple of days ago lost 1 leg and 2 more were on their way to the same state. The water is in really good shape, and the stars have been in the tank for awhile (exept for the african- he is new). I did have a battle with MV recently but that is just about cleared up and all of my surving fish are in QT. Can the stars be infected with MV? Does anyone know what is going on and how I can treat it if at all?
All your help is appreciated! Thanks all!

[ToddTT]

What else is in the tank?

And what is their diet?

[Ninong]

Can the stars be infected with MV?

No.

Does anyone know what is going on and how I can treat it if at all?

All sea stars are extremely sensitive to osmotic shock (sudden changes in salinity). Also, they require natural seawater salinity: 35 ppt (1.0264 SG).

There is nothing you can do to "treat" your sea stars. Just maintain natural seawater water parameters, including NSW salinity. Once they start falling apart, it's usually all over and they don't recover.

[Ninong]

Since you posted this in the Reef Aquariums forum, I will assume you have a reef tank. You should be aware that chocolate chip sea stars are not reef-aquarium safe. For one thing, they eat coral polyps. The sea star commonly called the red African sea star is another one that is not reef-aquarium safe. Can't say anything about your green one and your yellow one without a better description. If the green one is the notorious Atlantic green brittle star, then it's not safe either.

[gregony]

Like Ninong said, no one really knows how to treat sea stars. Brittle stars usually do well in mature tanks with lots of live rock, other starfish, not so much. They almost always waste away. It probably has nothing to do with your marine velvet outbreak, just coincidence. Starfish are usually predators that eat other inverts - corals, sponges, other starfish, etc. You can imagine the complications that this diet creates in an aquarium environment.

[shamrock]

I do not have a reef tank, I have 180g. tank currently with eels, a spiny puffer, an orange damsel and live rock and sand. I wish I knew what kind the green star and the yellow star are but unfortunatly I do not. I do know however that they are not brittles, they have thick bodies like the choc chips kind of speckled in color but without the chips.
I have recently put Formalin in the tank but I waited 7 hours before I put the stars back into the tank, (according to the formalin bottle it evaporates within 6 hours). Do you think that if there was any residual formalin in the tank that this could be the cause? I am really not sure what is wrong. We purchased this tank from someone who had it running for about 3 years and we have had it since Halloween.
Thanks again everyone for all of your imput i appreciate it.

[Ninong]

I do not have a reef tank, I have 180g. tank currently with eels, a spiny puffer, an orange damsel and live rock and sand. I wish I knew what kind the green star and the yellow star are but unfortunatly I do not. I do know however that they are not brittles, they have thick bodies like the choc chips kind of speckled in color but without the chips.
I have recently put Formalin in the tank but I waited 7 hours before I put the stars back into the tank, (according to the formalin bottle it evaporates within 6 hours). Do you think that if there was any residual formalin in the tank that this could be the cause? I am really not sure what is wrong. We purchased this tank from someone who had it running for about 3 years and we have had it since Halloween.
Thanks again everyone for all of your imput i appreciate it.

Okay, because your question involves formalin and because you have a FOWLR tank, I'm going to move you to the FOWLR forum because Lee has experience using formalin.

[leebca]

If the Formalin product you were using was specifically for salt water aquariums then its instructions should be fine to follow. No problem with this.

However, if the tank had other invertebrates (pods, benthic creatures, etc.) the Formalin could have done them harm. These creatures should have been there if you in fact have live rock like you wrote. You don't want to treat the whole tank with such a mix of marine life forms.

You might be new to the hobby -- it isn't clear other than the tank is relatively new to you. The invertebrates in the tank are not for beginners and even advanced aquarists would shun some of those invertebrates. Proper husbandry of them is highly unlikely in this case and their slow demise is expected.

You have a sort of 'advanced tank' but maybe just starting out. Go slowly and catch up by doing a lot of reading. In the meantime, remove those stars and then immediately perform a very large water change (over 85%) and get the water into a better quality zone.

You'll want to follow these guidelines for such a large water change: How to Make a Successful Water Change

In addition, read this post: Setting Up a FOWLR Aquarium I want you to read this post because I would like to give you a bigger picture on how things progress in setting up a tank AND how maintenance should be handled.