First Time Echinoderms and Tankmate Recommendations

[Ryan Kobert]

Hello. Since Christmas (and close after that, my birthday) are rapidly approaching, and since I've decided to pursue my passions for invertebrate biology, I'm seriously considering getting a little tank of invertebrates for me and my partner to fawn over. Specifically, I've been interested in Echinoderms, and have been wondering what species (and tankmates) would be best for somebody just being introduced to the hobby.

 

[livinlifeinBKK]

Hello. Since Christmas (and close after that, my birthday) are rapidly approaching, and since I've decided to pursue my passions for invertebrate biology, I'm seriously considering getting a little tank of invertebrates for me and my partner to fawn over. Specifically, I've been interested in Echinoderms, and have been wondering what species (and tankmates) would be best for somebody just being introduced to the hobby.

In terms of echinoderms steer clear of true starfish if you're new to the hobby until you not only gain experience but understand their biology a bit as well (i say this as I'm conducting an observational study of Fromia indica starfish and true starfish in general are MUCH more difficult to maintain than they may appear). Brittle stars or serpent stars generally do well (class Ophiuroidea) as do sediment feeding sea cucumbers (class holothuroidea)...these are the 2/5 classes of echinoderms that you should be able to maintain as a beginner...if you have further questions feel free to ask as I have a love for echinoderms and study them as much as I can!

 

[davidcalgary29]

Tuxedo urchins would be my first choice. They're remarkably hardy aquarium inverts.

 

[Ryan Kobert]

In terms of echinoderms steer clear of true starfish if you're new to the hobby until you not only gain experience but understand their biology a bit as well (i say this as I'm conducting an observational study of Fromia indica starfish and true starfish in general are MUCH more difficult to maintain than they may appear). Brittle stars or serpent stars generally do well (class Ophiuroidea) as do sediment feeding sea cucumbers (class holothuroidea)...these are the 2/5 classes of echinoderms that you should be able to maintain as a beginner...if you have further questions feel free to ask as I have a love for echinoderms and study them as much as I can!

That’s tough cause I think serpent stars and sea cucumbers are equally fascinating lol. I am curious as to how I would sustain a sediment feeding sea cucumber though, I would presume I would need something to produce the detritus it eats?

 

[livinlifeinBKK]

That’s tough cause I think serpent stars and sea cucumbers are equally fascinating lol. I am curious as to how I would sustain a sediment feeding sea cucumber though, I would presume I would need something to produce the detritus it eats?

If you don't have any fish you could ghost feed a little each day but I'd get a fish to form a more natural system. Serpent stars would also need some suspended food to catch or clean up from the sandbed.

 

[bnord]

cool, and like your avatar

small tuxedo urchins if you have algae on the rocks/glass, small pencils if the tank has Coraline, filter cucumbers (like a tiger tail) if you have a fair bit of detritus (but they are strictly nocturnal) and brittle/serpent stars that you can drop food down to

agree on the hit and mostly miss on the star fish (though my son has one of the most neglected tank I have ever seen, and he has had one for over a year

it'll be nice to see how it goes for you - and looking forward to you graduating to crinoids (smile)

 

[Ryan Kobert]

cool, and like your avatar

small tuxedo urchins if you have algae on the rocks/glass, small pencils if the tank has Coraline, filter cucumbers (like a tiger tail) if you have a fair bit of detritus (but they are strictly nocturnal) and brittle/serpent stars that you can drop food down to

agree on the hit and mostly miss on the star fish (though my son has one of the most neglected tank I have ever seen, and he has had one for over a year

it'll be nice to see how it goes for you - and looking forward to you graduating to crinoids (smile)

filter feeding sounds problematic in such a small system but I have not even begun to think about what sort of tank I should get. I have the feeling a small tank would not necessarily easier since it is more easily destabilized by wastes, and echinoderms are from what I’ve read are somewhat sensitive animals.

 

[ISpeakForTheSeas]

With regards to the sediment feeding cucumbers, as mentioned, you can ghost feed the tank and they'll do just fine on that. For example, the Chocolate Chip Sea Cucumber (Isostichopus badionotus) has been bred in captivity on the following diets*:
"Two feeding protocols were tested: In the first year, the broodstock were fed with commercial tilapia and rabbit feed which was ground, supplemented with Spirulina powder, and blended with disinfected beach sand (30g food/kg sand). In the second year, the food was changed to a mixture of ground Ulva sp., Sargassum sp., and Macrocystis sp. meals (Baja Kelp, Ensenanada, B.C., Mexico) blended with disinfected beach sand (30g algae mixture/kg sand). The food was changed every third day to prevent fungus formation."

I don't remember the other species I've looked at at the moment, but, generally speaking, sand sifting sea cucumbers are not picky about what they eat (though the food likely needs to be relatively decently sized so as to fit in with the sediment they're sifting - for example, the food they fed to the juvenile sea cucumbers when they reached 3 cm in the study above was sieved 55 at microns). Some easy foods you could offer that should work even for smaller cucumber species would be things like TDO Chromaboost Type A and Spirulina powder like used in the study I referenced.

If you do want to keep sea cucumbers, make sure you're tank is prepared for them (i.e. make sure the mechanical parts of the tank won't kill the sea cucumber), and make sure you know about the risks of keeping them (which are mostly to any fish in the system with them).

That said, from what I've seen with other people's tanks, I'd agree that Brittle/Serpent stars, sand sifting sea cucumbers, and some urchins are probably the easiest echinoderms to care for (possibly in that order) - starfish (with the noteworthy exception of Aquilonastra spp. stars, commonly erroneously called Asterina stars in the hobby) and crinoids are basically considered impossible at this point (though a number of coldwater starfish species have been aquacultured successfully, so if you want a coldwater tank, you do have a few good options there for starfish). If you really want a true starfish in a tropical tank, you can add some Aquilonastra stars (though they are often considered pests due to their typically quick reproduction rates, and some people believe they eat corals - specifically zoanthid corals), or you can try a sand sifting starfish (I don't recommend it, but if you want to try it I do have some feeding suggestions that may or may not help with long term success - no one has gotten back to me yet on if it has helped their stars or not, so I don't know for certain).

*The study:

https://onlinelibrary.wiley.com/doi/epdf/10.1111/jwas.12061

Edit: It sounds like a fun project to me - good luck, and welcome to Reef2Reef!

 

[Ryan Kobert]

With regards to the sediment feeding cucumbers, as mentioned, you can ghost feed the tank and they'll do just fine on that. For example, the Chocolate Chip Sea Cucumber (Isostichopus badionotus) has been bred in captivity on the following diets*:
"Two feeding protocols were tested: In the first year, the broodstock were fed with commercial tilapia and rabbit feed which was ground, supplemented with Spirulina powder, and blended with disinfected beach sand (30g food/kg sand). In the second year, the food was changed to a mixture of ground Ulva sp., Sargassum sp., and Macrocystis sp. meals (Baja Kelp, Ensenanada, B.C., Mexico) blended with disinfected beach sand (30g algae mixture/kg sand). The food was changed every third day to prevent fungus formation."

I don't remember the other species I've looked at at the moment, but, generally speaking, sand sifting sea cucumbers are not picky about what they eat (though the food likely needs to be relatively decently sized so as to fit in with the sediment they're sifting - for example, the food they fed to the juvenile sea cucumbers when they reached 3 cm in the study above was sieved 55 at microns). Some easy foods you could offer that should work even for smaller cucumber species would be things like TDO Chromaboost Type A and Spirulina powder like used in the study I referenced.

If you do want to keep sea cucumbers, make sure you're tank is prepared for them (i.e. make sure the mechanical parts of the tank won't kill the sea cucumber), and make sure you know about the risks of keeping them (which are mostly to any fish in the system with them).

That said, from what I've seen with other people's tanks, I'd agree that Brittle/Serpent stars, sand sifting sea cucumbers, and some urchins are probably the easiest echinoderms to care for (possibly in that order) - starfish (with the noteworthy exception of Aquilonastra spp. stars, commonly erroneously called Asterina stars in the hobby) and crinoids are basically considered impossible at this point (though a number of coldwater starfish species have been aquacultured successfully, so if you want a coldwater tank, you do have a few good options there for starfish). If you really want a true starfish in a tropical tank, you can add some Aquilonastra stars (though they are often considered pests due to their typically quick reproduction rates, and some people believe they eat corals - specifically zoanthid corals), or you can try a sand sifting starfish (I don't recommend it, but if you want to try it I do have some feeding suggestions that may or may not help with long term success - no one has gotten back to me yet on if it has helped their stars or not, so I don't know for certain).

*The study:

https://onlinelibrary.wiley.com/doi/epdf/10.1111/jwas.12061

Edit: It sounds like a fun project to me - good luck, and welcome to Reef2Reef!

Thank you for such a technical response! I suppose now I have to ask how to have equipment that doesn’t injure the animals. Is it a matter of placing it out of reach or cucumber proofing it somehow?

 

[ISpeakForTheSeas]

Thank you for such a technical response! I suppose now I have to ask how to have equipment that doesn’t injure the animals. Is it a matter of placing it out of reach or cucumber proofing it somehow?

Generally speaking, you cucumber proof it like you would anemone proof a tank - you basically just make sure your cucumber isn't going to be caught or pureed by your mechanical equipment. This can usually be accomplished by simply adding "nem guards" to your powerheads and making sure the cuke can't get stuck in your pumps, overflows, plumbing, etc. You also obviously want to make sure you don't have anything that will prey on sea cucumbers, but few things in the hobby do, so I wouldn't be too concerned about that.

If anyone else has other tips for cuke proofing, I hope they'll chime in, but that's basically it as far as I know.

 

[livinlifeinBKK]

Just get one that's appropriate for your tank size (i didn't see you mention how big your tank is) because if for whatever weird reason it happened to die it would release significant amounts of ammonia...no size chart or anything, just use your judgement when buying one if your tank is relatively small. I've never had this happen and it wouldn't be expected for it to die because they're pretty easy to care for but I have heard of people whose tanks were nuked by really big sea cucumbers. The stories I heard were most specifically related to sea apples which are filter feeders closely related to the sediment eaters (sea apples are big and beautiful and sometimes just referred to simply as cucumbers at some LFSs since they technically are one type). They're pretty easy to distinguish from sediment eaters that crawl around the sandbed eating all day though.

 

[Ryan Kobert]

Just get one that's appropriate for your tank size (i didn't see you mention how big your tank is) because if for whatever weird reason it happened to die it would release significant amounts of ammonia...no size chart or anything, just use your judgement when buying one if your tank is relatively small. I've never had this happen and it wouldn't be expected for it to die because they're pretty easy to care for but I have heard of people whose tanks were nuked by really big sea cucumbers. The stories I heard were most specifically related to sea apples which are filter feeders closely related to the sediment eaters (sea apples are big and beautiful and sometimes just referred to simply as cucumbers at some LFSs since they technically are one type). They're pretty easy to distinguish from sediment eaters that crawl around the sandbed eating all day though.

I have not thought about tank size yet, though I would like to shoot for something around the 20g range. The apartment me and my partner plan to move into isnt terribly large so I can’t have a nice big installation like some other folks here.

 

[ISpeakForTheSeas]

Just get one that's appropriate for your tank size (i didn't see you mention how big your tank is) because if for whatever weird reason it happened to die it would release significant amounts of ammonia...no size chart or anything, just use your judgement when buying one if your tank is relatively small. I've never had this happen and it wouldn't be expected for it to die because they're pretty easy to care for but I have heard of people whose tanks were nuked by really big sea cucumbers. The stories I heard were most specifically related to sea apples which are filter feeders closely related to the sediment eaters (sea apples are big and beautiful and sometimes just referred to simply as cucumbers at some LFSs since they technically are one type). They're pretty easy to distinguish from sediment eaters that crawl around the sandbed eating all day though.

Just to add to this, it’s actually not so much the ammonia to worry about (though you would need to worry about that too) with these as it is the Holothurin (sea cucumber toxins), and it’s mostly what I was alluding to above when I mentioned the risks of keeping a sea cucumber - Sea Apples in particular are known for releasing large quantities of the toxin, but all sea cucumbers have at least some of it.

Some really good (in my opinion) but somewhat disorganized info about the toxin in the link below:

What to do with Medusa worm?

I found about 3-4 Medusa Worms in my tank, I have read that they can be beneficial to help the CUC. But also have heard if stressed they can kill all life in tank. Right now they are only about 1/2” long. My question is leave them or somehow try to remove them. more info 75 gallon DT 25 gallon...

www.reef2reef.com

An example of a “Cuke Nuke” with some more good info:

EMERGENCY - Anemone Toxin / Sea Cucumber Toxin

Hi! Unfortunately, this morning I woke up to all my fish deceased, the sea cucumber and anemone also dead, with some gooey like slime stuck in my return pump. All of my crabs and snails are alive including my pom-pom, Anemone Crab and my Conchs, critters I thought to be extremely sensitive...

www.reef2reef.com

 

[Spare time]

Serpent and brittle stars arey favorite clean up crew members. Plus they seem to compete with bristle worms