Has anyone kept a Granulated/Doughboy Sea Star?

[ReeferHD]

Hey guys!
I have the opportunity to get a Granulated sea star (Choriaster granulatus) but I want to make sure I can feed it, Wikipedia says their main diet is coral polyps and Carrion (meat?)
I don't have a problem with spot feeding and if I can keep it sustainably on a meaty food diet I will definitely go for it. the tank I'll be putting it in has some invasive soft corals too if that helps. appreciate any kind of input!

Ryan.

 

[ReeferHD]

@ISpeakForTheSeas ?

 

[ISpeakForTheSeas]

@ISpeakForTheSeas ?

There's a lot of conflicting info on these out there, and most of the more likely to be reputable info is hidden behind paywalls, but from what I can find, these seem to primarily feed on carrion - so dead meaty foods - and are thought to feed on biofilms as well (it would not surprise me if they're primarily biofilm-feeders that are opportunistically carnivorous though).

I've seen some sources saying that they feed on algae, and it wouldn't surprise me if they feed on a little algae too (purposefully or accidentally), but I wouldn't expect it to be their main feed or even a major component of their diet (though I have seen it claimed that these are mainly herbivorous starfish - I doubt that claim).

I have also seen reports of them eating inverts and corals (including some claiming that corals are a primary food for the star), but from most (annoyingly, not all) of the scholarly sources I've come across, I would assume these are probably (but not guaranteeably) rarely eaten in the wild.

Many of the sources I was able to track down mentioned them feed on carrion and corals in the aquarium holding tanks of the studies, not in the wild - from the behavior of other starfish in captivity (such as the biofilm-feeding chocolate chip starfish), I would assume corals are more likely "famine foods" (i.e. less-desirable than their primary wild foods) and inverts more likely opportunistic foods for the star (since most healthy inverts would outrun them readily), with both being more likely to be eaten in aquariums than in the wild.


Anyway, more to the point of your question, I'm not sure if it would last long-term on a meaty diet being spot-fed, but I would personally assume either the biofilm portion or coral portion of their diet is more important than expected, and, as a result, I would guess the star would last probably 2-3 years being spot-fed (though I could be wildly off here).

If you decide to give it a try, let us know what you purposefully feed it, what it actually eats (if you can tell), and how it does over time.

Here is a final note on their diet and a list of some health cues to look for that may help with telling how it's doing:

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.

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). [Edit: you may also be able to tell if the star is looking lean/gaunt or full/puffy; gaunt is generally not good.]
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).

 

[Mr_Knightley]

@ISpeakForTheSeas covered all the big points, but I have some extra notes for maintaining biofilm-feeders. My favorite way to feed them, though I would certainly warn against this, is to clip a piece of meat to the glass down by the sand bed and let it stew for a day or two; after a bacterial film grows on it, the stars somehow sense it and will mob the meat and strip it clean. I use salmon for this usually and it keeps my Linckias happy and fat. Simple foods like nutritional yeast are also valuable, I feed this to my chocolate chip star when he breaches the water surface.
It's tough to know if we're feeding the right foods since no official stomach analyses have taken place, but that fact that they actively gravitate towards the bacterial films I introduce gives me some meager confidence. I would be careful doing this method in aquariums smaller than 100 gallons though for fear of a nutrient spike.

 

[ISpeakForTheSeas]

@ISpeakForTheSeas covered all the big points, but I have some extra notes for maintaining biofilm-feeders. My favorite way to feed them, though I would certainly warn against this, is to clip a piece of meat to the glass down by the sand bed and let it stew for a day or two; after a bacterial film grows on it, the stars somehow sense it and will mob the meat and strip it clean. I use salmon for this usually and it keeps my Linckias happy and fat. Simple foods like nutritional yeast are also valuable, I feed this to my chocolate chip star when he breaches the water surface.
It's tough to know if we're feeding the right foods since no official stomach analyses have taken place, but that fact that they actively gravitate towards the bacterial films I introduce gives me some meager confidence. I would be careful doing this method in aquariums smaller than 100 gallons though for fear of a nutrient spike.

Very interesting method there - I wonder how the biofilm composition of the meat compares to that found on the natural food surfaces for the stars (I know Chocolate Chip Stars feed primarily on the biofilms of seagrass and macroalgae in the wild; I'm not sure with the Linckias, but I assume their biofilms are primarily on the rocks).

How long have you had your stars for?

 

[Mr_Knightley]

Very interesting method there - I wonder how the biofilm composition of the meat compares to that found on the natural food surfaces for the stars (I know Chocolate Chip Stars feed primarily on the biofilms of seagrass and macroalgae in the wild; I'm not sure with the Linckias, but I assume their biofilms are primarily on the rocks).

How long have you had your stars for?

Going on about a year now, so my results are certainly not definitive. But I like the fact that the stars seems to "smell" it and will intentionally seek it out.

 

[ISpeakForTheSeas]

Going on about a year now, so my results are certainly not definitive. But I like the fact that the stars seems to "smell" it and will intentionally seek it out.

Yeah, that's definitely a good sign and quite interesting - IIRC, with livinlifeinBKK's fromias that they would reject food that wasn't fresh enough; I wonder if they would have accepted it with more time for the food to spoil/accumulate different bacteria.