What’s on my Trochus snail shell?

JonnyDabs710 · Oct 29, 2023

I bought a couple trochus snails a week ago and one has this fuzzy black claw looking thing on its shell. Anyone know what it is or if it is a concern to the tank?

https://youtube.com/shorts/Ik97A5UoXuo?si=PGIdhW8lqxEK_dVY

EeyoreIsMySpiritAnimal · Oct 29, 2023

Wow! Never seen that before.

@ISpeakForTheSeas , any ideas?

Reefkeepers Archive · Oct 29, 2023

EeyoreIsMySpiritAnimal said:
Wow! Never seen that before.

@ISpeakForTheSeas , any ideas?

I second that! I do see some hairs on it, looks to be filter-feeding. @ISpeakForTheSeas ?

ISpeakForTheSeas · Oct 29, 2023

EeyoreIsMySpiritAnimal said:
Wow! Never seen that before.

@ISpeakForTheSeas , any ideas?

I can’t see the “fuzzy” parts well enough to be sure, but I’m almost positive this is a Sabellariid worm, possibly a Phragmatopoma sp. (Sandcastle Worms); I’m a lot less confident on the genus at this point than the family, but it should have an operculum (basically a body part trap door it can close itself into its tube with), and the morphology of the operculum can be used to help determine the genus. Regardless, if it’s from the Sabellariidae family, then it should be a harmless filter feeder (it would be considered a type of Feather Duster Worm).

Some of the species in the family are colonial, and the colony’s tubes can form reefs - they’re one of my favorite kinds of inverts.

EeyoreIsMySpiritAnimal · Oct 29, 2023

ISpeakForTheSeas said:
I can’t see the “fuzzy” parts well enough to be sure, but I’m almost positive this is a Sabellariid worm, possibly a Phragmatopoma sp. (Sandcastle Worms); I’m a lot less confident on the genus at this point than the family, but it should have an operculum (basically a body part trap door it can close itself into its tube with), and the morphology of the operculum can be used to help determine the genus. Regardless, if it’s from the Sabellariidae family, then it should be a harmless filter feeder (it would be considered a type of Feather Duster Worm).

Some of the species in the family are colonial, and the colony’s tubes can form reefs - they’re one of my favorite kinds of inverts.

But it looks like a pincher coming out of the shell...

JoJosReef · Oct 29, 2023

Following, very curious.

ISpeakForTheSeas · Oct 29, 2023

EeyoreIsMySpiritAnimal said:
But it looks like a pincher coming out of the shell...

Yeah, the closest I can find at the moment is Idanthyrsus pennatus (only a handful of images pull up if you search the species on Google - about four of the images show a claw-like shape; three have white worms, one has a black specimen).

Regardless, OP, it may help to pull the snail out in a bowl of tank water and snap some pics of the critter (assuming it withdraws into its tube to hide during the process, taking a straight-on pic of the tube’s entrance may be informative as well).

JonnyDabs710 · Oct 29, 2023

I tried really hard to get some type of picture of this guy, sorry in advance. You’re Gunna have to zoom in because the camera won’t focus very well

EeyoreIsMySpiritAnimal · Oct 29, 2023

ISpeakForTheSeas said:
Yeah, the closest I can find at the moment is Idanthyrsus pennatus (only a handful of images pull up if you search the species on Google - about four of the images show a claw-like shape; three have white worms, one has a black specimen).

Regardless, OP, it may help to pull the snail out in a bowl of tank water and snap some pics of the critter (assuming it withdraws into its tube to hide during the process, taking a straight-on pic of the tube’s entrance may be informative as well).

Very cool!

JonnyDabs710 · Oct 29, 2023

JonnyDabs710 said:
I tried really hard to get some type of picture of this guy, sorry in advance. You’re Gunna have to zoom in because the camera won’t focus very well

This one might be better

EeyoreIsMySpiritAnimal · Oct 29, 2023

JonnyDabs710 said:
This one might be better

Oooh, it's so cute! Looks just like the Idanthyrsus pennatus that @ISpeakForTheSeas suggested!

JonnyDabs710 · Oct 30, 2023

@ISpeakForTheSeas if it is Idanthyrsus pennatus would that be a keeper or a cause for concern? I can’t find much information on them. The couple of pictures on google kind of looks like it.

ISpeakForTheSeas · Oct 30, 2023

JonnyDabs710 said:
@ISpeakForTheSeas if it is Idanthyrsus pennatus would that be a keeper or a cause for concern? I can’t find much information on them. The couple of pictures on google kind of looks like it.

Yeah, so Idanthyrsus pennatus is a Sabellariid worm; like I said in my first post, I'm not entirely sure on the genus/species of the worm (though an Idanthyrsus sp. seems like a pretty good guess to me at this point), but any Sabellariid worm is going to be a harmless/beneficial filter feeder.

So this worm would be a keeper and no cause for concern - it's literally a type of feather duster tube worm, so it's just going to hide in it's sand tube and feed on tiny particles like phytoplankton.

Reefkeepers Archive · Oct 30, 2023

ISpeakForTheSeas said:
Yeah, so Idanthyrsus pennatus is a Sabellariid worm; like I said in my first post, I'm not entirely sure on the genus/species of the worm (though an Idanthyrsus sp. seems like a pretty good guess to me at this point), but any Sabellariid worm is going to be a harmless/beneficial filter feeder.

So this worm would be a keeper and no cause for concern - it's literally a type of feather duster tube worm, so it's just going to hide in it's sand tube and feed on tiny particles like phytoplankton.

Why does everyone else find these hitchhikers? I only find bristleworms and sea spiders

JonnyDabs710 · Oct 30, 2023

Reefkeepers Archive said:
Why does everyone else find these hitchhikers? I only find bristleworms and sea spiders

Don’t worry I got bristleworms too

ISpeakForTheSeas · Oct 30, 2023

Reefkeepers Archive said:
Why does everyone else find these hitchhikers? I only find bristleworms and sea spiders

Haha, luck of the draw I guess.

JonnyDabs710 · Oct 30, 2023

ISpeakForTheSeas said:
Yeah, so Idanthyrsus pennatus is a Sabellariid worm; like I said in my first post, I'm not entirely sure on the genus/species of the worm (though an Idanthyrsus sp. seems like a pretty good guess to me at this point), but any Sabellariid worm is going to be a harmless/beneficial filter feeder.

So this worm would be a keeper and no cause for concern - it's literally a type of feather duster tube worm, so it's just going to hide in it's sand tube and feed on tiny particles like phytoplankton.

Awesome, thank you for your time and help. Just 4 months in so I tend to worry a bit too much.