Pond Boss Forums MANAGING AN EXISTING POND Corrective stocking dreaded bucket stocking Part 2... 'Mystery Snails'

I noticed some very large looking snails this summer all along the shores. I meant to look them up and today it crossed my to do list and I did some googling. Unfortunately, I'm afraid I have the Chinese (or Japanese) mystery snails in abundance!

Since my pond has no inlet and no outlet, these probably came from my not so helpful neighbor who emptied his aquarium into my pond the day before he moved out of the house. Another reason to enforce (as best as one can) the NO BUCKET STOCKING rule.

Not sure the impact on my pond yet. They seem to multiply like rabbits. Not sure if filtering the water will be helpful or harmful. I also know my RES will not be able to control their numbers at least the adults as they get very big!

Some articles:

Big snails in small ponds


MSU extension article


Anyone else have these? Any other pros or cons to report in ponds that do have these?

My snails seem to stay in about 3" of water in the shallows so I can rake them out easily enough but how many are there in the deep?

I can try to post pictures but they seem to match the online images.

That sucks. Not all is lost though. Just because they become too large at some point doesn't mean your fish won't crop them when they're smaller.

Are you aware the reason the redear are so large in Lake Havasu and the channel on Santee Cooper is due to exotic snails?

The racoon's will have a field day with those. They wear out the mussels in my pond.

Escargot??

Baked in garlic butter!

Pictures!!

3-4 in every camera frame:








with 'foot extended':



Anyone know for sure what these are?

Holy.... Canyon I'm sorry you have to endure uninvited residents in your pond, but your story is a picture perfect example of how an ecosystem can be altered and/or impacted by an uninformed neighbor.

I know I know, the bucket event is bad news. I guess I'm not sure how much regret to feel as I don't know if these snails are bad or good yet. Perhaps they filter the water for me, I don't know. But I will probably try to rake the 'adults' out since it is easy to do and hope the RES take care of the 'babies'.

I bet even the great RES pictures on this forum would have a hard time choking down one of these monsters.

I wonder if I can sell them to local folk who buy them for their aquariums?

The bucket stocker told me he put a bullhead in. Still wondering if he did or not or if I'll ever see the bullhead or his activity again.

Do bullhead bite on trotlines overnight?

What he did to my pond reminds me of the old returning from the honeymoon prank where someone takes your entire pantry and takes off all the labels of your canned goods. Every time you open a can (or in my case walk around the pond) you never know what you might find....

Dinner.

esshup, you should have been at my house this weekend. I 'harvested' using a wide landscape rake at least a hundred pounds of these snails. I didn't weigh them, but it is backbreaking work and I filled a five gallon bucket about 4 times. Then this week i went back around and found even more smaller ones. I think they are migrating out of the deep into the shallows. Some that I raked on shore and missed as they were under the weeds ended up trying to get back in the water. Neat to see the snail moving VERY slowly with a little trail in the mud behind them.

I figure I have removed 80% of the larger ones now. I'll keep at it. I read they can live up to 6 months out of the water but hopefully with coming winter they won't make it. I threw them in the woods about 100' or so from the pond. Hopefully some woodland critters will find a way to enjoy a good meal on the piles of snails there.

Perhaps the snails were helping with water clarity? don't know.

I did see that after some of the snails laid in the sun for the day that little tiny red worms were crawling out of the gap in their shell between their 'foot' and the shell covering. Probably part of the parasite cycle or something, yuch! I didn't have my camera with me...

I should have posted a CL ad and see if the local aquarium enthusiasts would have been interested in buying them from me. But on the other hand, I don't want to introduce any parasites to someone's aquarium either.

Canyon, soak those suckers in some brine solution for a few minutes....don't let them migrate elsewhere!

Four, 5-gallon buckets of snails? That's amazing. Goes to show how easy it is to introduce an unwanted organism into a BOW.

we have them in our chain of lakes in WI, the DNR Biologist told me they classify them and "non native" but not "invasive". We have loads of them but she said they have no real effect on the ecosystem or other organisms in our lake.

How are we certain that the presence of the snails was due to 'bucket stocking?'

I would think there were may vectors existing in Mother Nature.

Maybe even turtles and snapping turtles.

I think it may be a case of a non-native species showing up. Maybe they weren't bucket stocked into Canyon's pond by a neighbor, but somewhere, sometime, those snails became a part of the ecosystem.

Maybe they migrated from pond A to pond B, without a bucket. Or maybe an animal carried them. But if they are non-native, then how did they end up in pond A in the first place?

If we cared to chase it back, I'm betting we would encounter a human presence somewhere.

Yes, I can't prove the aquarium contents of the neighbor had these snails. I did transfer some water along with the fish when I stocked the perch (doubt any snails in there as just water and fish but who knows), with the RES and LES and LCS they came from zimmerman and only fish in the bag, tilapia came from a local aquaculture source so it is possible snails came in that way. Also had GSH and FHM from a bait wholesaler in Minnesota so certainly could have come from there.

But the BOW that had the snail certainly had to get it from somewhere.

I'm glad to hear that they are not native but also not harmful. I'll harvest adults, easy to pick ones and see what happens over time.

The tiny red worms crawling out from the snail shell could have been blood worms actually midge larvae Chironomidae.
http://www.wetwebmedia.com/fwsubwebindex/BloodwormF.htm

There are also reddish tubifix worms although often not quite as red but more wormlike than the midge larva.
http://www.allabout-aquariumfish.com/2009/01/aquarium-live-food.html

Bill, it did look like it could be blood worms, but at least the more mature blood worms seem to have a head with some 'feelers' and segments in their body. These would have been very 'miniature or immature' red worms, very smooth, featureless body and no defined head or tail section.

how they got inside the snail shell with the snail is beyond me...

This is a neat page showing a ghost shrimp eating a blood worm. I imagine these larvae don't stand much of a chance with shrimp, scuds, and fish of all types around waiting to snap them up.

see this:

Blood worm bye bye...

Smallest bloodworms (early instars) are pretty featureless unless one looks closely. The larger ones in the pictures are late stages of larva development. There is likely a little room inside the snail shell for a few bloodworms to take refuge and feed on detritus around the snail shell. It is possible the worms were parasites. Closer examination is needed for a more positive identification.

These snails are in some of our local ponds also. Perch should make a good dent in them if needed. I have seen the perch suck the innards right out of the land snails I chuck in. We have tons of land snails about the size of these, but their shells are not quite so thick.

Interestingly the mice and voles love escargot, so when you lift up something the mice have been living under, there are piles of snail shells akin to a clam bake.

liquidsquid, thanks for the post and your observations. I continue to remove the large ones that I see by shore (in the water and close enough to reach) and let the perch eat the smaller ones.

You reminded me of something, I left huge piles of these things in the woods. I need to check to see if anything worked them over for lunch or if the snails made a move back towards my pond.

Mash them and throw back into pond the fish should scarf them up

Pat,
This year I don't see as many large/adults in the shallows. Maybe half as many as last year so the perch are probably eating the young (born live as I can read online) I have adopted your tip. The shells are very thin. I pull them out, set them on the ground, step on it, grab the nasty/gooey mess, toss it back in the pond and assume that the perch will take care of the rest.

They might be filtering the water and clearing it, not sure, but they tend to hang out in 6" of water or less and are too tempting to purge from the pond I see them stuck to all sides of the pallets but those probably are safe for now.