Are these whelks?

[Jstn]

I got 6 of these large snails from my LFS, they bagged them up with a few other inverts so I wasn’t paying attention, they are large 1”-1.5”.

Updated pic of the snails in question

 

[Lovemyreef2015]

They look like nassarius snails. I don't think they are welks

 

[Jstn]

I’m leaning towards whelks for the brown ones, I found an empty large Trocus shell a few days back, and last night I knocked a large one off the glass, it landed on its shell. Usually they upright themselves so I don’t worry, but this morning I discovered this snail was being eaten by a single large “Nassarius” (resembling the ones in the first pictures). I removed both and the trocus didn’t smell of death that rotting snails usually have, it was a fresh kill.

 

[Lovemyreef2015]

Nassarius snails can have different shells from where they came from . Examples below

 

[Jstn]

These are whelks for sure, one I left 3 of them in my qt with the trocus it that’s death is in question. None of them touch the dead rotting corpse, another data point. Also came home to seeing another potential whelk out feasting or killing a mother trocus (in the middle of the day) needless to say this isn’t The behavior of a nassarius snail. Also the shells posted before have a “looser” slope between the turns of their shells. These large snails
In question have a more tighter pointed shell. Almost like a bullet tip.

Here is the rotting trocus (don’t mine the other little shells and the one true nassarius, I alway toss dead snails in qt to see if they are indeed dead before tossing.

 

[Jstn]

To be clear in my first post the white one is most likely a nassarius, it’s these black ones that are the ones in question.

 

[ReefQueen]

I agree, those do not look like whelks to me either.

 

[Jstn]

Here is the paralyzed snail, not dead not moving

 

[Gareth elliott]

Does the snail in question bury?

Any pattern on the snorkel?

Hard bottom shell that acts as a man hole cover when inside its shell?

For the paralyzed snail new or old? If new how was it acclimated? any salinity variations last few days? On the shell what are those small things, there are tiny snails that are preadtors.

 

[Jstn]

Kinda bury, it remains mostly exposed

It has color on its snorkel not a pattern but not clear

It appears to have a trap door on the end of it’s food.

They also look a lot like Ilynassa Obsoleta in terms of color and shell shape, not perfect.

 

[Jstn]

Does the snail in question bury?

Any pattern on the snorkel?

Hard bottom shell that acts as a man hole cover when inside its shell?

For the paralyzed snail new or old? If new how was it acclimated? any salinity variations last few days? On the shell what are those small things, there are tiny snails that are preadtors.

Best image

The paralyzed snails are 3-4 years old established trocus, quite large and covered in coralline.

 

[Gareth elliott]

What the trapdoor looks like on a whelk.

 

[Jstn]

What the trapdoor looks like on a whelk.

Yes it looks like that with two filiments off the back, I will try to get better pics of this door.

 

[DSC reef]

Looks like a nassarius to me

 

[Jstn]

Here are better pics, also that trocus in the second picture is dead, stinks like it’s dead
And none of these snails has touched it,
Mind you I haven’t added food to this tank so the only meal is the rotting snail or each other.

One can see in the second picture the trap door vaguely.

 

[ReefQueen]

I am not seeing the typical whelk pattern, sort of like a snow leopard. Also see the ridges on the inside of the shell? Whelks are smoother on the inside.

 

[Jstn]

I am not seeing the typical whelk pattern, sort of like a snow leopard. Also see the ridges on the inside of the shell? Whelks are smoother on the inside.

Thanks what makes it difficult, they don’t look like whelks but their behavior makes me think either way they aren’t reef safe.

 

[ReefQueen]

Thanks what makes it difficult, they don’t look like whelks but their behavior makes me think either way they aren’t reef safe.

You’re welcome. you could always return them to the LFS to put your mind at ease.