Hydroid? picture

[wombat1]

I believe these are hydroids. They have a hard tube they retract into. Does anyone else have experience eradicating them, or can tell me how fast they spread? Is this the correct ID?

 

[Len]

Yup, those are hydroids for sure. This type can be a bit aggressive since they pack a good sting and are rather fast growers (does very well in captivity feeding on suspension detritus and bacteria). When they grow in abundance, they can sting neighboring cnidarians. They're easily killed though with kalkwasswer past or steaming hot water. The tube is not actually calcium, but protein (and hard!).

 

[wombat1]

Hmmm, not inject it, just squirt it on them? How about crushing them and siphoning off the remains?

 

[liquid]

Crush them, squish them, paste them over with kalkwasser powder, smother them with epoxy...it all works. And yep, those are hydroids. I've got a nice patch of them that I've not erradicated yet.

Shane

 

[Anonymous]

so you can crush these guys and not worry about them coming back??

 

[Anonymous]

Supa, you can't just crush them. I haven't *really* tried getting rid of them yet, but I tried to rip them off and smother them. Neither worked.

 

[Anonymous]

I had a real bad case of hydroids that seemed to finally crash, now there's none. I did notice that they wouldn't grow around a certain sponge of mine, and as it grew, they disappeared. I thought maby it was chemical warfare, but that's just a thought, nothin to back it up other then what I saw,