What's up with my Strombus?

[martin.a]

Hi Guys,

I am looking for advice/diagnosis of what's up with my Strombus.

One of my four Strombus snails crawled under a rock and dug itself halfway into the sand, then stopped moving and feeding. It has been like this for over a week now! The other three snails are acting normally.

I assumed it had died and took it out. It was retracted, but clearly alive. After I put it back into the water, it crawled back under that rock and assumed exactly the same motionless position.

From time to time, it pokes one of its eye stalks up to look around. The last time I took it out and sniffed it was two days ago. The picture below was taken a few hours ago. Sorry about the quality, it is a distant, dark spot, but you can see the eye stalk sticking up. (It sucked it back in a moment later.)

All four snails were introduced into the tank about two weeks ago. They spent the first 2-3 days madly decimating the local diatom population. After that, they slowed down, and this one crawled under the rock. The other three keep working, more slowly than at the beginning, but seem fine.

This is a new tank with Trochus, Astraea, cowries and peppermint shrimps. No deaths recorded, no obvious signs of a dino bloom.

 

[Mickle]

Maybe dying from stress, improper acclimation, or not enough food. Ive never heard of this behavior before

 

[martin.a]

Sick/dying was my hypothesis too. But it's still alive, and looking at the world around. I have seen it today reaching a bit around with proboscis to eat some algae growing around. Still no movement and remains half-buried. Whenever I get it out it then buries itself. I may have the first ever recorded Strombus with depression. Maybe I should try Prozac.

 

[martin.a]

Update:
After visit from a friend:

It felt better and started cautiously grazing around:

It has moved more than 150mm since and continue grazing. Maybe it lives... I will keep updated in case somebody cares and for the record.

 

[martin.a]

Another update: The snail in question is back in action. After nearly 2 weeks of not eating, not moving and staying half-buried in the sand. Probably this closes this topic. I will post again in case it does something extraordinary again.