Hitchhiker. How long have I not noticed him?

[fachatga]

Just did a water change and vacuumed part of my sand bed. Must have unearthed this guy. Noticed a new shell moving around a few hours later. It was out of place. I know what my CUC looks like. I know what kind of snail this is but the thing is I’ve never bought one. Got here somehow. I was just surprised how big it is. I had this thing get into my tank and it sat in the sand and got pretty big before I noticed it. So I figured I’d pose the question: what’s the biggest thing you found in your tank you didn’t put there? How big can a hitchhiker get before we find them? Thankfully these guys are good. Wonder what else is hiding

 

[fishguy242]

it's always cool to find something good in the reef...

 

[TnFishwater98]

It took me 8 months and I discovered this Cephalochordata. Saw him move inside a hole in the LR a few times but finally got a picture.
If this isn’t a Cephalochordata please let me know.

 

[fachatga]

I almost didn’t believe the lfs guy who started me off who told me I’ll see something in my tank one day that came in with the rock. I was so clueless when I started lol.

 

[TnFishwater98]

Actually just found this! Thought it Looked like a baby limpet but it had a orange skirt? Soft shell but a circle tip with same orange. Is this a flatworm?

 

[TnFishwater98]

I wasn’t trying to highjack your thread. Thank you for posting. I went to my tank to look after I read your post and found that. I started a new post and hopeful get clarification soon.

 

[Tamberav]

Actually just found this! Thought it Looked like a baby limpet but it had a orange skirt? Soft shell but a circle tip with same orange. Is this a flatworm?

frilly limpet. A good snail. I have one in my reef too.

 

[robbyg]

The biggest thing has been Octopuses that must have been Penny sized in the live rock I dived up. I did not see that first one until he was about 6-8" across.

The most common thing you will find are massive Bristle worms. I think anyone who has had a tank for several years eventually finds a massive one that is 10-12" long. I have seen some posts on here of ones much longer than that, maybe 20"

 

[Alexopora]

Actually just found this! Thought it Looked like a baby limpet but it had a orange skirt? Soft shell but a circle tip with same orange. Is this a flatworm?

To be precise this is Lucapina, a type of keyhole limpet.