Brittle starfish deteriorating or being attacked?

[bgilson]

I made a post about this before. I have had this starfish for quite some time. Not a new tank. Late last week I noticed him out and about during light hours. Noticed the file fish, valentini puffer, and convict tang were pecking at him. Noticed he was missing some stuff. Pics below. It seems to have gotten worse and he wasnt moving very well today so I had to call it quits. Just want to know opinions or possible facts. He def has “bite” marks on the legs and one leg was completely short. The center part is what originally got my attention. First pic is first time I noticed. Other two are just of tonight.

 

[Tinnerito]

I made a post about this before. I have had this starfish for quite some time. Not a new tank. Late last week I noticed him out and about during light hours. Noticed the file fish, valentini puffer, and convict tang were pecking at him. Noticed he was missing some stuff. Pics below. It seems to have gotten worse and he wasnt moving very well today so I had to call it quits. Just want to know opinions or possible facts. He def has “bite” marks on the legs and one leg was completely short. The center part is what originally got my attention. First pic is first time I noticed. Other two are just of tonight.

You typically want to temporarily separate the aggressors in either another tank, or in the same tank with a partition, since you don't want your fish pecking at your brittle star. If it continues, you may want to separate them permanantly.

 

[bgilson]

They typically arent aggressive. No issues with anything else in the tank. Him being out during light hours was more surprising.

You typically want to temporarily separate the aggressors in either another tank, or in the same tank with a partition, since you don't want your fish pecking at your brittle star. If it continues, you may want to separate them permanantly.

 

[Jay Hemdal Verified Community Expert]

I made a post about this before. I have had this starfish for quite some time. Not a new tank. Late last week I noticed him out and about during light hours. Noticed the file fish, valentini puffer, and convict tang were pecking at him. Noticed he was missing some stuff. Pics below. It seems to have gotten worse and he wasnt moving very well today so I had to call it quits. Just want to know opinions or possible facts. He def has “bite” marks on the legs and one leg was completely short. The center part is what originally got my attention. First pic is first time I noticed. Other two are just of tonight.

When I see a brittle star with the skin of its central body missing to that extent, I generally euthanize them. Magnesium salts can be used, but freezing is easier and they really don’t have a developed nervous system so they don’t feel pain.

 

[bgilson]

When I see a brittle star with the skin of its central body missing to that extent, I generally euthanize them. Magnesium salts can be used, but freezing is easier and they really don’t have a developed nervous system so they don’t feel pain.

He has been euthanized

 

[Tinnerito]

They typically arent aggressive. No issues with anything else in the tank. Him being out during light hours was more surprising.

Are you sure that the starfish is getting enough food and nutrients? Have you had any recent salinity swings? The only times I've had nocturnal inverts surface at daylight is when they're either desperate for food, or this one time I had a mysterious salinity shift in one of my systems.