difficulty with stars

[sedorusc]

I have had a med-lrg brittle star for months. I have tried introducing other stars (sandsifter and linkia) but they both seemed to have a decaying of the legs I don't know if they were harrassed by something. I do have a few small brittle stars and I've read parents can be aggressive. The fish do not bother the stars. I also have a decorator arrow craband several shrimp. I was just wondering if these could be the problem.

 

[graveyardworm]

There certainly could be a predator there bothering the stars, but more than likely its either an acclimation or a food issue. Stars generally require a long aclimation, and most are specialized feeders and are unable to find enough food to meet their needs in the average aquarium. Decaying of the legs is a typical sign that the animal is starving. Here's an article to read.

 

[sedorusc]

I acclimated the most recent (a red linkia) for three hours using the drip method. I try to put plenty of seeweed sheets in the tank. they never seem to be eaten though. I haven't had any trouble with any other stars and even have small brittle or serpent, too small to tell, that are doing well.

 

[graveyardworm]

Brittles and serpents are fairly easy to care for, they are scavengers and will eat fish leftovers so feeding is easy. The linkia and sand sifting stars have specific diets, and generally wont eat anything else when their food source becomes sparse they dont turn to other food sources they starve. Not to say this is what has happened here you may very well have something preying on your stars.

You have alot of competition for the same food source, the arrow crabs, the shrimp, and the sand sifter all have similar diets. While the arrow crab and shrimp will turn to other food sources, the sand sifter has a specialized diet.

A quote about linkia from the article I provided.

Individuals of Linckia species, particularly Linckia laevigata, are profoundly and seriously harmed by rapid changes in salinity; additionally, they appear to suffer "shipping" stress. As a result these animals need to be treated VERY carefully during acclimation to the home aquarium. This acclimation should be done slowly, and; acclimations of more than six to eight hours are often required. Once established in aquaria, Linckia generally appear to do well and may persist for a year or more. However, they often seem to slowly die, probably due to a lack of some specific dietary item. For large animals, they are surprisingly benign. They seldom knock over rockwork, and do not harm most other animals while they are dying.