Can I get an ID on this worm

[Omakoshark]

 

[Omakoshark]

It came in some red ogo algae. What is it? I am hesitant to put it in the tank.

 

[Omakoshark]

 

[AcroNem]

I almost said flat worm, but if has those "tentacles" at one end it is a Medusa worm.

 

[35ppt]

Medusa worm for sure. Good guy.

 

[Omakoshark]

So keep him?

 

[35ppt]

So keep him?

I would. It's technically a cucumber.

 

[Omakoshark]

Are they poisonous to coral, fish, etc. I heard they were.

 

[Mikedawg]

Just in case you really like unidentified worms: http://chucksaddiction.thefishestate.net/hitchworms.html

Couldn't tell from pic - do they have triangle shaped heads? Okay, blew pic up and see tentacles - Medusa I think. If you want to examine further would help to remove it from bag and macro background.

If it truly is a Medusa I don't believe it is as toxic as a cucumber; hey, adds diversity which IMHO is a good thing.

 

[35ppt]

Are they poisonous to coral, fish, etc. I heard they were.

Cucumbers can release a toxin if stressed or killed but I've never actually heard of it happening and killing a tank so I believe the concern to be overblown. I could be wrong, if you're not into it sell it or give it away.

 

[35ppt]

Are they poisonous to coral, fish, etc. I heard they were.

In the most general terms, virtually any soft-bodied animal that would make easy prey on a coral reef, such as these sea cucumbers, will typically be defended in some way by distasteful chemicals or physical armament, and medusa worms are no exception. Like virtually all sea cucumbers, they are soft- bodied, lacking any real physical armament, and so they all tend to have a variety of nasty chemicals associated with their bodies to deter predators from feeding on them. Even without the Cuvierian tubules and their potent toxins, medusa worms have a variety of distasteful chemicals associated with the skin and body wall to protect them from being eaten by fishes, crabs and lobsters on the coral reef. Although the specific toxins associated with synaptid cucumbers are somewhat different from those of most other cucumbers studied to date (Kuznetsova et al. 1989; Ponomarenko et al. 2001), these animals are still reported to be highly toxic to fishes in marine aquaria if they are seriously injured (e.g., Delbeek and Sprung 1994; Fenner 2000; Michael undated online; Sprung 2001). In general, toxins are only released when the cucumbers are under severe stress (such as being chewed up after being sucked into a powerhead or overflow grate), and a diligent aquarist will usually prevent this from ever happening, and therefore never experience any problems with one of these animals. If however, and accident happens, and the cucumber is stressed severely enough to release its chemical defenses, then a good water change, together with an efficient skimmer and some activated carbon are usually sufficient to prevent any fish from asphyxiating from the soap-like holothurin.

Aquarium Invertebrates: The Medusa Worms

All-in-all, however, despite how fascinating these animals are, unless you are confident of the identification of the animal, can provide suitable conditions for the animal to feed, and are willing to live with the potential drawbacks of keeping one of these animals in an aquarium, they are not...

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