Dead sea cucumber toxin

[CannaJake]

Hello tankmates! I recently had a sea cucumber die in a small 10 gallon tank. I have read they can possibly release a toxin when they die. I did an ammonia test and 0 ppm. Should I do a 100% water change or should I even worry about it? The only other things in the tank were live rock and 2 emerald crabs and the crabs are fine. Thank you for your advice and input my friends!

 

[timmyrules]

Sea cucumbers only release toxins if they are cut up in a power head, filter, wave maker, etc…that’s a common misconception. If it wasn’t cut up, I wouldn’t worry about it. But if you’re super worried, you could always do a 20% water change. I’ve had one die in a 5 gallon tank before, and nothing happened…I think you’ll be fine

 

[CannaJake]

Thank you for the reassurance! I already did a 80% water change so I should definitely be fine then

 

[littlefoxx]

Mine got into a return pump. Nuked my tank.

 

[livinlifeinBKK]

It depends on the species when they release their toxin. Heres a Reef Builders article on suspension-feeding cucumbers:

How to Maintain Suspension-Feeding Sea Cucumbers | Reef Builders | The Reef and Saltwater Aquarium Blog

When most hobbyists imagine sea cucumbers, or holothuroid species as they’ll be referred to later, we envision bottom-dwelling detritivores with little personalities whose slug-like bodies made their…

reefbuilders.com

 

[CannaJake]

It depends on the species when they release their toxin. Heres a Reef Builders article on suspension-feeding cucumbers:

How to Maintain Suspension-Feeding Sea Cucumbers | Reef Builders | The Reef and Saltwater Aquarium Blog

When most hobbyists imagine sea cucumbers, or holothuroid species as they’ll be referred to later, we envision bottom-dwelling detritivores with little personalities whose slug-like bodies made their…

reefbuilders.com

Thank you! I will definitely read this even though Im def not getting another one after learning about the toxin danger!

 

[livinlifeinBKK]

Thank you! I will definitely read this even though Im def not getting another one after learning about the toxin danger!

The holothurin toxin is dangerous but after reading the article you might change your mind...

 

[eliaslikesfish]

sea cucumbers are a vibe. get a sea apple. cucumbers won’t kill everything unless they get torn up

 

[livinlifeinBKK]

sea cucumbers are a vibe. get a sea apple. cucumbers won’t kill everything unless they get torn up

the article on Reef Builders I posted is actually about suspension feeding cucumbers like sea apples! Watch it too if you want!

How to Maintain Suspension-Feeding Sea Cucumbers | Reef Builders | The Reef and Saltwater Aquarium Blog

When most hobbyists imagine sea cucumbers, or holothuroid species as they’ll be referred to later, we envision bottom-dwelling detritivores with little personalities whose slug-like bodies made their…

reefbuilders.com

 

[ISpeakForTheSeas]

Just to add a little more info on the toxin itself:

Whether or not you decide to keep them is up to you - some people like them, others think they’re not worth the risk. To help you decide if they might be worth the risk, here’s a sizable info dump.

If you keep them fed and have your tank set up to hold them (i.e. make sure they can’t get sucked into powerheads/filters, make sure they can’t torch themselves on your heater, etc.), then they are typically beneficial.

However, from what I’ve read, it seems literally all sea cucumber (medusa worms included) do have the toxins you’re concerned about to some degree or another. The part that’s hard is that how much toxin the cuke contains and how likely a cuke is to release those toxins varies from species to species. Some species are substantially more prone to releasing the toxins than others, and some release a good deal more of the toxin than others. An important note here, the toxin of sea cucumbers (holothurin) is an ichthyotoxin (it primarily affects fish, though in high enough quantities it can affect other things like inverts and people too), so if the cucumber does release its toxin into the tank, the inverts might be fine. For more info, here’s a post I made referencing and expounding upon another of my posts on the subject from a while ago:


As mentioned, many sea cucumbers will release toxins when stressed/dying, so it's important to keep them happy and to be prepared to deal with that situation should it arise (i.e. be prepared to do an emergency water change, add carbon, transfer livestock to a hospital tank, etc.) - some cukes are highly toxic, some only mildly, some release toxin when stressed, others only release it once their corpse starts to decay, etc. so the risk varies a lot depending on the species, but unless they're one of the highly toxic species (like Sea Apples) it's not usually too big of a concern. Plus, many species will give warnings that they're dying/stressed, so sometimes people are able to get a heads up that they need to remove them (see my quote below for more info).

TLDR; nem guards are good idea for sea cucumbers.

Some sea cucumbers like to just pick a spot and stay there, so it might just decide not to move. Given that you said this one started real small and kept growing, it's possible you just had all three come in at the same time, possibly from the same batch of baby sea cucumbers. If that's the case you either could have just missed them because they were so small, or the other two may have just moved over there because the conditions there are more favorable for their larger size than the previous area they were in.

Regardless, most sea cucumbers are generally safe in reef tanks (not much tries to eat them, so generally you don't need to worry about them getting overly stressed), but you should probably make sure your equipment is sea cucumber safe (i.e. you want to make sure they can't get pureed by going into one of your powerheads or something), and - as was mentioned above - they can release toxins when they die, so you'll want to keep an eye out for that. A lot of sea cucumbers will give you some sort of warning before they die (such as contracting to look short and squat - a defense mechanism/sign of extreme distress that they use to try and escape predators/death - or ejecting a cloud of toxins - because of how this actually works, the cucumber generally dies after releasing the toxins), and some of them, as long as they don't get hyper distressed, (as I understand it) won't intentionally release toxins in your tank - they just die like a normal animal, so as long as you remove the body fast enough, it won't poison your tank.

On the off chance that they do decide to release toxins into your tank, if you catch it early enough, you can run carbon, do a big water change, and (if necessary) transfer your livestock to another tank. I would strongly recommend using protective equipment in this case as some sea cucumbers when they release toxins can be dangerous to humans, but, ideally you wouldn't need to worry about it. Ideally, you'd just remove the cucumber either soon before or soon after it dies (the people I've talked to said they didn't need to run carbon or anything when theirs died in their tank, so as long as you catch it before the body starts degrading you should pretty much be fine as I understand it).

Lots of scary info there, but generally sea cucumbers are safe to keep, and as long as they are physically safe from harm in your tank the chances of them "cuke nuking" it by releasing toxins into your tank are very slim.

Hope this helps!

Yeah, I've only heard of a couple of instances where a "cuke nuke" actually took place despite knowing multiple instances of cucumbers ejecting either a toxic fluid, their organs, or their cuvierian tubules, so it's definitely not a common event (at least not with sand sifting species). That said, keep in mind that the toxicity varies from one species to the next, and some species are more toxic in certain ways (some are more toxic when they expel toxins in some way, others contain more toxin in their body wall, etc.), and various circumstances (such as water volume, skimmers, running carbon or not, etc.) about the aquarium they're in can determine how much harm the toxin causes.

Personally, I'd say they generally seem pretty safe, but you need to be aware of the (relatively low) risk and have a plan in place to handle it if things go awry.

The cuke nukings:

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

https://www.sciencedirect.com/science/article/abs/pii/S1557506321000483

An instance of ejecting a fluid (nothing seemed to have been harmed in the tank, but this stuff is reportedly toxic):

EMERGENCY - New Black Sea Cucumber Red Stuff

Hey all, I recently got a black sea cucumber. I acclimated it with the drip method, and after a day it is now expelling this stuff. I've ready a lot about the toxicity, but I'm not sure if I should pull him now or not. All my SPS and fish seem to be fine.

www.reef2reef.com

 

[CannaJake]

sea cucumbers are a vibe. get a sea apple. cucumbers won’t kill everything unless they get torn up

Those are beautiful! I will definitely check into these! Thank you! Ive never seen these!

 

[CannaJake]

Just to add a little more info on the toxin itself:

Wow this is great! I need to learn how to find these articles on R2R. Im still new to thw platform so I'm still figuring it out.