Snail on my hermit crab?

[kazeespada]

My halloween Hermit crab seems to have a snail riding aboard it. I thought all the creatures on its shell were dead, but I guess not. It's got black antenna and a black siphon shaped mouth it uses to grab food from the rock the hermit crab is eating from. It has made a round turban shaped shell. What is it? My friend thinks it's a slipper snail, but I wanted to make sure.

 

[Stephen8169301]

My halloween Hermit crab seems to have a snail riding aboard it. I thought all the creatures on its shell were dead, but I guess not. It's got black antenna and a black siphon shaped mouth it uses to grab food from the rock the hermit crab is eating from. It has made a round turban shaped shell. What is it? My friend thinks it's a slipper snail, but I wanted to make sure.

Could it be a feather duster worm? Does it move to different spots on the shell?

 

[ISpeakForTheSeas]

My halloween Hermit crab seems to have a snail riding aboard it. I thought all the creatures on its shell were dead, but I guess not. It's got black antenna and a black siphon shaped mouth it uses to grab food from the rock the hermit crab is eating from. It has made a round turban shaped shell. What is it? My friend thinks it's a slipper snail, but I wanted to make sure.

Slipper limpet/slipper snail is a good guess - I’d add hoof snail to the list of possibilities too. I need to do a bit more studying up on the differences between these groups to tell for sure which one you have (I know some hoof snails use a long proboscis - the siphon mouth - for feeding this way, I’m not sure if some slipper limpets/snails do too or not), but - either way - they’re harmless to their host and neutral/good for a reef tank.

 

[kazeespada]

Could it be a feather duster worm? Does it move to different spots on the shell?

It generally doesn't move. It's been there the whole time I've had this hermit crab(about a week and a half), today is the first time I saw it extend to feed.

 

[Stephen8169301]

It generally doesn't move. It's been there the whole time I've had this hermit crab(about a week and a half), today is the first time I saw it extend to feed.

Did it look like this

 

[kazeespada]

Slipper limpet/slipper snail is a good guess - I’d add hoof snail to the list of possibilities too. I need to do a bit more studying up on the differences between these groups to tell for sure which one you have (I know some hoof snails use a long proboscis - the siphon mouth - for feeding this way, I’m not sure if some slipper limpets/snails do too or not), but - either way - they’re harmless to their host and neutral/good for a reef tank.

I looked up hoof snails, and found a picture that was 1 to 1 of what I saw. The black antennae and the proboscis. Sorry, I called it a siphon earlier.

Did it look like this

Nope. It had a proboscis, and no feathers.

 

[ISpeakForTheSeas]

Sorry, I called it a siphon earlier.

No problem - I’m still picking up a lot of the technical terms myself, and the way you described it was good enough to get the idea across (which is the important part with things like this from a hobbyist perspective). Glad you were able to confirm the ID, and welcome to Reef2Reef!

 

[1epauletteshark]

I had something that looked like this on my hermit crab after he switched shells and he was very lethargic, I thought it was just a bump in the shell but then I saw this thing lift up and there was a little black foot and maybe antenna and something clicked in my brain. I thought this must be the problem so I picked up the crab and I took it out and I had to crack open the shell of the limpet thing and take it off because it had bored into the hermit crab’s shell and I couldn’t pluck it off. After that he was ok and active so maybe this was the same thing? I am not too sure but I had something similar.

 

[ISpeakForTheSeas]

I had something that looked like this on my hermit crab after he switched shells and he was very lethargic, I thought it was just a bump in the shell but then I saw this thing lift up and there was a little black foot and maybe antenna and something clicked in my brain. I thought this must be the problem so I picked up the crab and I took it out and I had to crack open the shell of the limpet thing and take it off because it had bored into the hermit crab’s shell and I couldn’t pluck it off. After that he was ok and active so maybe this was the same thing? I am not too sure but I had something similar.

Some of these snails are known to basically grow onto/into the shell of their host (though I don’t think they typically would grow into the cavity of the shell, just the wall of the shell). If it was a slipper limpet/snail or hoof snail on the hermit, I’d imagine the extra weight on the shell would have been the problem rather than the snail itself, as from everything I’ve read, the snails are harmless.

 

[1epauletteshark]

Some of these snails are known to basically grow onto/into the shell of their host (though I don’t think they typically would grow into the cavity of the shell, just the wall of the shell). If it was a slipper limpet/snail or hoof snail on the hermit, I’d imagine the extra weight on the shell would have been the problem rather than the snail itself, as from everything I’ve read, the snails are harmless.

He was a small electric blue hermit so all that extra weight was too much, I was confused at why it didn’t move back into it‘s old shell so I decided to intervene.

 

[kazeespada]

He was a small electric blue hermit so all that extra weight was too much, I was confused at why it didn’t move back into it‘s old shell so I decided to intervene.

I have found that hermits will sometimes just pick up a shell too big for them. Give them some time to grow the muscles and they will start being active again. I recently had a Dwarf Zebra move into a conch shell(I guess she wanted to match the size of the Halloween), and it took her a few days to adjust to that shell.