What is this

[gus5783]

Any ideas what this is. Find in my tank yesterday. Have not added anything to my tank since oct. First thought was aptasia. Closer look makes it look like urchin. But have also been told maybe a hyoid stage jelly. Any help please.

 

[flower]

Looks like a hydroid jelly fish to me, they sting, so not a good guy... our live rock has all kinds of critters living in and on it, which is why it's called live rock. If you didn't add it, it came as a hitchhiker.

 

[gus5783]

which i have gad my fair share of hitchhikers, just never seen anything like this. nor have i heard of having hitch hikers appear 4 moths later. not only that but i have never heard of anything hitchhiking in on live stock. havent added live rock in over a year.

 

[honu808]

I first set up a 55 gal. 6 months later I changed over to a 125 reef. When I made the switch I found a HUGE black slug looking thing. We never did identify it on here so I kept it in the 125. Never saw it again. Strange how many cridders we don't see nor buy, but are there. lol

 

[pegasus]

I had a case of hydroid jellies in my old 29 gallon tank. I netted all that I could see, but only after I (finally) found the colony was I able to get rid of them.

 

[pegasus]

I first set up a 55 gal. 6 months later I changed over to a 125 reef. When I made the switch I found a HUGE black slug looking thing. We never did identify it on here so I kept it in the 125. Never saw it again. Strange how many cridders we don't see nor buy, but are there. lol

Did it look like this? Big picture is a top/side view. The small picture is a bottom view.

 

[honu808]

Did it look like this? Big picture is a top/side view. The small picture is a bottom view.
View attachment 653

Yep but no blue on it. The pictured one is awesome looking.

 

[pegasus]

How about this one?

 

[pegasus]

Yep but no blue on it. The pictured one is awesome looking.

It's called Chelidonura varians. Identifiable by it's two elongated tail segments.

 

[honu808]

Sort of, but i didnt see a distinguishable head and or tail.

 

[bang guy]

Take a look at pictures of black Flatworms.