Is this sand sifting star a gonner?

[magnificentNovice]

I picked up a used 40g tank a year ago that was already filled with fish, inverts and corals-- among them was a sand sifting star. I read that they really prefer larger tanks, but the previous owner had kept it for over a year and they seemed conscientious about every other part of their setup so I kept the star. I monitored him closely for signs of starvation of failing health but he seemed to keep on going strong.

Recently I noticed a tip of one of his legs looked short, and I wondered if I may have accidentally got him with the algae scraper. Today he emerged from the sand with bright white patches that look pretty dire. I didn't see this kind of discoloration even 2 days ago.

Is there any chance it's something that will pass, or is this the end? If so, what should I do with him to humanely remove him to keep the rest of my tank safe?

Is there a chance that he'd survive if I re-home him to a much bigger tank, or has that ship already sailed?

 

[Dan_P]

I picked up a used 40g tank a year ago that was already filled with fish, inverts and corals-- among them was a sand sifting star. I read that they really prefer larger tanks, but the previous owner had kept it for over a year and they seemed conscientious about every other part of their setup so I kept the star. I monitored him closely for signs of starvation of failing health but he seemed to keep on going strong.

Recently I noticed a tip of one of his legs looked short, and I wondered if I may have accidentally got him with the algae scraper. Today he emerged from the sand with bright white patches that look pretty dire. I didn't see this kind of discoloration even 2 days ago.

Is there any chance it's something that will pass, or is this the end? If so, what should I do with him to humanely remove him to keep the rest of my tank safe?

Is there a chance that he'd survive if I re-home him to a much bigger tank, or has that ship already sailed?

A photo under white light is always the most useful.

I don’t think the sand sifters last many years.

 

[Stomatopods17]

the white is the "bone" beads and sign of deterioration. if it gets worse in that spot (as in, its not the result of physical damage and likely an infection) you can amputate the entire leg and it'll grow back slowly. Its very safe to do as long as the cutters are clean (I use bone cutters, you can find cheap ones in reef kits).

If its not localized and can be spotted in other areas, the star is just on its way out likely due to starvation and the beginning of that is point of no return. Sand sifters do not last long in aquariums because they eat specific matter in the sandbed which they deplete quickly over time, they just help aerate the sand rather than eat anything else like extra food, detritus, etc.

 

[magnificentNovice]

the white is the "bone" beads and sign of deterioration. if it gets worse in that spot (as in, its not the result of physical damage and likely an infection) you can amputate the entire leg and it'll grow back slowly. Its very safe to do as long as the cutters are clean (I use bone cutters, you can find cheap ones in reef kits).

If its not localized and can be spotted in other areas, the star is just on its way out likely due to starvation and the beginning of that is point of no return. Sand sifters do not last long in aquariums because they eat specific matter in the sandbed which they deplete quickly over time, they just help aerate the sand rather than eat anything else like extra food, detritus, etc.

Thanks for the detailed reply. It wasn't localized and it makes sense that it's starvation. I'm just bummed because I would have seen it coming and rehomed him 6 months ago, but I decided to keep an eye on him. He was looking great until he suddenly wasn't. I won't be buying another star unless it's in a much larger tank.

 

[ISpeakForTheSeas]

I know I'm late, but typically once white patches start showing up, it's too late for the star (though there are rare exceptions).

If the star made it two years in aquariums, then it has long outlived the average I've seen.

For what it's worth, the larger tank may or may not help - it's still a gamble. The best I can offer for sand-sifting starfish at this point are the quotes below:

You can target feed them, but no one has gotten back to me yet on if it helps:

These starfish don’t eat algae in any meaningful quantities. They’re probably carnivorous, but may be detritivorous (see the quotes below). Personally, I’d try putting the star in an acclimation box with a dish of sand for it, and I’d try offering it a bunch of mollusks for it to eat (clams, mussels, oysters, and small but meat-eating snails like Nassarius snails would be my suggestions at this point), and see if it shows interest in eating any of them. If it does, then I’d try offering it more of that item in various sizes and see if it has a preferred food size.

I'd try something like clam, oyster, etc. and/or snail meat (you can find various frozen/live marine snails to try online, including conch meat, periwinkle snails, babylonian snails, etc.)

The quote below is specifically geared toward Astropecten spp. (predatory) sand sifting stars, but there is another genus of sand sifting stars called Archaster that is thought (importantly the diet was inferred, not studied in the research that this diet was pulled from) to be detritivorous (specifically, they are thought to be microphagous detritivores). I have heard but cannot confirm that Archaster spp. misidentified as Astropecten spp. may be more common in the hobby than actual Astropecten spp. are.

So, with this in mind:
- If your star is detritivorous (which may be a very big if), then you would likely want smaller foods than the suggested below (which is designed for predatory sand sifters). In this case, I'd suggest trying to mix something like TDO Chroma Boost into the sand for your stars to find.
- If your star is predatory (which may to our limited knowledge be possible at this point even if it is an Archaster sp.), then the below advice (and my advice above) is more likely to be useful.
- If your star is actually primarily a biofilm eater like Linckia spp. Protoreaster nodosus, etc. (which may also to our limited knowledge be possible for an Archaster sp.), then it's likely to die regardless of what you do or don't feed it at this point.

I’ve heard they climb the glass when they’re looking for food and can’t find any in the sand bed.

Generally, people recommend large tanks and waiting until your tank is established before trying these (or pretty much any) sea stars, and the star survives on detritus in the tank. Unfortunately, even in a lot of these tanks, after they finish clearing the detritus from the sand, they typically starve.

My current advice to avoid the star staving - which may or may not help, I genuinely don't know at this point (it could take someone months to years of testing it to find out for certain, as sea stars can last months without food):
Target feed the star things like clam on half shell, oyster, mussel, scallop, etc. (bivalves); snail, whelk, conch, etc. (sea snail gastropods); and a good quality omnivore food (like LRS Reef Frenzy or Fertility Frenzy). These are - according to the best sources of information I can find - the sorts of foods sand sifting stars consume in the wild, and the star should swallow these foods whole if they aren't too big - you might need to experiment a bit with the size of the pieces offered to get it sized just right, but generally I'd say err on the smaller side.

If you decide to give it a shot, let me know how it goes, and keep me updated on the long term survival of the star!

Edit: Forgot:

Some ways to potentially gauge the health of the starfish that may be useful:
1 - Visual: is anything visually wrong with the specimen? (From what I know of starfish, these cues are generally pretty obvious if they're there at all - if the starfish is disintegrating, there's something wrong).
2 - Weight: is the specimen putting on or maintaining weight (generally healthy), or is it losing weight (under most circumstances, this would be unhealthy)?
3 - Size/Length: if it's not already full size, is the specimen growing? Is it shrinking (either from weight loss, disease, limb loss, etc.)?
4 - Reproduction: is the specimen engaging in reproductive behaviors/activities (i.e. courting, nesting, spawning, etc.)? (I recognize this one is not as common of an indicator in captive starfish at this point, but there are a few instances of starfish attempting to spawn in captivity).
5 - Longevity: is the specimen relatively close to meeting, actually meeting, or exceeding their expected wild lifespan (or at least surviving for a few years - healthy), or is the specimen dead/dying prior to doing so (unhealthy)?
6 - Speed: how quickly can the specimen right itself when it's flipped over?
7 - Level of activity: how much is the specimen moving around? (Generally speaking, low activity indicates poor health; moderate activity indicates good health; and high activity indicates good health but probable stress - it could be searching for food, oxygen, etc., but it's probably not in terrible health when moving a lot).
8 - Grip strength: does the specimen have a strong hold/grip with its tube feet? (A strong grip indicates good health, a weak grip indicates poor health).
9 - Willingness to eat: is the specimen eating? (Seems obvious, but can be really hard to tell with some stars - some stars leave little trails called feeding scars through the things they're eating; sometimes you can see their everted stomachs; other times, like if they're feeding on biofilm, you may not be able to tell at all - them crawling onto visible food is a good sign they're willing to eat, but - as mentioned above - the food may or may not meet their nutritional needs).

And a final note on starfish keeping:

One important thing to keep in mind with foods for these guys - just because they eat it, doesn't mean it's meeting their nutritional needs; it might be, but it might not be. With how long it seems to take these guys to starve, unless you're monitoring their health closely, you might not notice if it's not meeting their needs until it's too late.

 

[magnificentNovice]

Thanks for the thorough response! The white spread a little and I put him in the freezer :( lesson learned, I don't put anything new in the tank without research anymore.

I know I'm late, but typically once white patches start showing up, it's too late for the star (though there are rare exceptions).

If the star made it two years in aquariums, then it has long outlived the average I've seen.

For what it's worth, the larger tank may or may not help - it's still a gamble. The best I can offer for sand-sifting starfish at this point are the quotes below:



Edit: Forgot:

And a final note on starfish keeping: