I've read suggestions to target feed linckia's but never heard suggested anything to try. I tried everything I could think of and they just wouldn't eat it. I'm pretty much convinced they are after slime. Well, more likely, the bacteria that grows on the slime coating of stuff. Maybe some figure out that they can eat other things but most won't. They'll just last a couple months. I did have a blue linckia last 2 years but that was one out of maybe 4 linckia's, the rest lasted anywhere from 2 weeks to a couple months at most. The few times I tried fromia's they didn't even last a week. And this was after drip acclimating over 12 to 24 hours so it's not like I didn't take my time acclimating ... these animals just simply don't do well in captivity.

The long and the short of it is that still, nobody know what they eat and they are doomed to die prematurely in an aquarium. Where thy last decades on a reef we are lucky to get months or a year out of them. For some reason, if it were a fish that was guaranteed to starve in an aquarium people would be upset at the continued importation of them, but being is it is an invert, it seem to be O.K.

From http://www.reefkeeping.com/issues/2004-12/rs/index.php (It is the third part of a three part series if you are interested.)

Now that I am done my rant, the best part of the article was likely the last two sentences about Linckia stars which states “For large animals they are surprisingly benign. They seldom knock over rock work and do not harm most other animals while they are dying.”

I agree. People need to be more aware of how difficult if not impossible most starfish are to keep. Most should be left in the ocean.

I'm sure there's some starfish that will do okay (thinking serpents and Chocolate Chip) but would say if your looking at one that no-one knows what it eats (or can't maintain a food supply), probably stay away.

I had a Blue Linckia for 23 months, did notice it eating some black sponge. Problem there was it clean the patches off and the sponge never grew back.

I have had a chocolate chip star (brought it back to LFS long ago) and pillow starfish (had to bring them back as well... they eat mushrooms, ricordias and one ate my bubble coral. Perhaps they were not getting what they needed to eat and went to my softies. Never again, but lesson learned and nobody starved.

I am always told to get a sand sifting starfish, but would a sand sifting goby to the same job essentially? Also if a sand sifting goby can do the job, how many are recommended per 100g of water? If I had one of two in my 260g, would they be able to get enough to eat? A goby seems to be very busy and always sifting so I wonder if they do get what they need, even with one in my 260g at the moment.

Thats the answer! Most of the "reef safe stars" Blue, red, orange, are sponge eaters, I have had a blue for about a year now and it makes it's way around from rock to rock eating the multipule colored encrusting sponges that grow in my live rock "Purple, yellow, pink,black and white sponge" but I have noticed that over the last couple of months the sponge colonies haven't been able to grow back fast eanough to sustain the growth of the blue star. My tank is 300gal and after seeing this I would'nt recomend anyone keep these creatures unless you can aford to buy live sponge to feed it.

Your tank is too young for either starfish or sand sifting gobies. You have to wait for your tank to mature at least 6-8 months, but 12 months would be much better. Pillow Starfish are known to eat corals, and Chocolate Chip Starfish are near impossible to keep long term. I would consider both species better left in the ocean. Conches do a great job of tank cleaning - Fighting Conch or Orange Lipped Conch. I would suggest one for every 4 sq ft of sand. Bigger tanks could possibly sustain a Queen Conch, but I would suggest their keeping to the more experienced aquarists out there as they are a rather demanding species. You still need to wait for your tank to mature before adding Conches.

I agree that they may eat sponges when there is not their natural food. There is a good picture of one eating a much smaller star on Eric Broneman's forum (or perhaps it was Dr. Ron's...) and the comment it elicited from whichever expert it was is that while it may eat that in captivity when starving it is not the stars preferred diet. To this date nobody has done the research necessary to state what they eat though it is thought to likely be some bacteria and slime in their natural environment. When starving a person may eat grass (or Mc Donalds) but that does not make it a diet that will support our life for very long (especially the Mc. D's...)