Nassarius or whelk

[Yasha Hase]

So this was sold to me as a nassarius snail and has been in the tank with a cerith and a trochus snail which he hasn't bothered so far. He buries himself in the sand but usually only about 2/3 to 3/4 of the way just curious as to if he's actually a nassarius or not. He also has a green and yellow tear drop shape trap door on his foot that I couldn't get a picture of.

 

[Gareth elliott]

Looks like a nassarius to me. But more opinions are always better than one.
#reefsquad

 

[saltyhog]

Snout looks like a whelk to me. The tattooed appearance to it often indicates a whelk. Nassarius usually have a solid color proboscis. One way is to watch it's behavior. If it spends a lot of time on the rocks or glass...especially during the day it's likely a whelk. Nassarius are sand dwellars that come out of the sand like a pack of zombies when you feed and at night but I rarely see mine during the day.

 

[Yasha Hase]

I've never seen it on the rocks and it only goes on the glass when I've fed the tank mysis and it's chasing some down. Is it normal for nassarius snails to only partially bury themselves?

 

[ReefQueen]

It is definitely a nass and not a whelk.

 

[reef lover]

Any kind of trap door says whelk..nass dont have them.

 

[glb]

The shell looks different than a nassarius. Agree with everyone else that nassarius stay in the sandbed and do the zombie thing.

 

[Ron Reefman]

And there you have it. The old saying goes, "Ask 10 people a question about an aquarium and you'll get 15 different answers!"

Even 2 Reef Squad members disagree about what it is. My wife and I are Shell Ambassadors at the Bailey Mathews National Shell Museum on Sanibel Island in SW Florida and neither of us can make a solid ID based on the limited info and a few reasonably good photos either.

I agree that a trap door would indicate a whelk, but we are missing that info. Yasha Hase, can you put it in a glass bowl and take some photos? And when you pull it out of the tank you should be able to tell us if it has a trap door.

Good luck.

 

[saltyhog]

I did read one article some time ago that the trap door and patterned snout are not exclusive to whelks, just the majority of the time. It's really hard sometimes to tell the difference as nassarius are actualy whelks (just ones that feed on detritus). Ultimately their feeding habits are the deciding factor....sooooo just put an expensive clam in front of it and see if it kills it! LOL, just kidding. I've always gone by the theory that when in doubt sump it.

 

[ReefQueen]

I have yet to see a whelk that has ridges on the inside of the shell as seen in the first pic.

 

[reef lover]

Me neither....but op stated it has a trap door and ive yet to see a nass with one...could b wrong...:confused:

 

[Yasha Hase]

I'll pull him out tonight to get some better pictures, and he definitely does have the trap door. When I noticed it I looked it up which is what led me to wondering if he actually was a nassarius or not.

 

[ReefQueen]

Just pulled 2 nass. Out at work and both have trap doors.

 

[Lovemyreef2015]

@ReefQueen yours look like nassarius snails. Nassarius snails do have trap doors. But the OP snail looks like a welk to me.

 

[reef lover]

I recant...apparently the nass has it on his shell and the whelk on his foot...

 

[KJ]

Agree with @Lovemyreef2015 and [USER=26086]@reef lover[/USER]

 

[LilElroyJetson]

I’m leaning towards nassarius but not confident in saying that. Wanted to add that my nassarius typically keep to the sand bed but when the tank gets fed they have no problem going up onto the rockwork and I’ve seen them as high as half way up my 18” glass for what it’s worth.