Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations High snail population

Paddled around in the Kayak for a little over an hour making a new Bathymetric map. It is 2.2 acres and the deepest is 10.2 ft. Average is about 5 ft.



When I pulled out the Kayak the bottom was covered in Snails.

I added 200, 3-5 inch RES on March 15. They should be growing well.
I'm concerned about parasites.
Should I add more or is this amount normal?

Looks just like mine a year after rebuild. 2 years after I added RES , couldn't find a snail, and still can't I'd say, give them some time, before spending any more cash. The proverbial $.02 .

We typically stock 500/ac.

You could deploy some under water surfaces to gather snails. Monitor (count) the snail infestation on a regular basis and record the results per under water object. Increasing means you need more RES. Decreaseing numbers means RES are doing their job.

RES have pharyngeal "teeth" at the back of their throats to enable them to crush shells.

I suspect your RES just aren't quite big enough to crush snail shells yet.

Small snail shells are almost as tough to crack as larger snail shells. However, the crushing force of small RES has to be significantly less than larger RES that have 10x the muscle mass.

Based on simple physics, I bet there is a "critical mass" for RES to reach before they can easily crush snail shells. Once they reach that size, I suspect they will quickly deplete your population of tasty snails.

(All of the above is rank speculation on my part. However, I bet someone that has access to the academic journals could readily find some actual research results on that topic.)

Thanks Bill

I have several plastic artificial trees that I built. They are great attractants. I'll do that.

One good thing about your type of snails is they are a specie of Physella acuta aka the bladder snail. They are known for their thin, oval shells and rapid reproduction. These snails are a very common type of snail in ponds and they have about the thinnest shell of most the various aquatic snails. This makes them easy for snail eating fish to successfully eat them. Yellow perch will even eat Physella snails. Pick up a couple of them and it is relatively easy to smash or crush them with your fingers. Smaller RES 3"-5" are able to eat the small and medium ones and larger RES consume the larger Physella. Most all of the other commonly occurring snails have a thick shell and not easily crushed.

Bill (and all others),

For the fish parasites that require a snail population during some portion of the life cycle:

Where the snail population consists of species with very hard/strong shells as adults, is there a point in the snail maturation curve where RES can eat the younger snails when they have smaller and/or weaker shells in sufficient numbers to break the propagation of the parasites?

Yes- the smallest and small snails of hard thick shelled species compared to those large adult individuals will be easier to eat by snail eating fish. Catfish can and do eat large snails and clams - depending on size and specie of catfish.
This from Minnesota DNR - Channel catfish eat crayfish, insects, snails, small clams, worms, fish, and the seeds of elm and silver maple trees. They primarily feed at night, which is the best time to catch them.

This from In-fisherman magazine –
https://www.in-fisherman.com/editorial/blue-catfish-baitfish-and-mussels/154642#replay

For the hundredth time; Thanks Bill!

Fun story. I ran a trotline a couple of nights at my dad's pond. Didn't have time to bait one day, and didn't pull it. Went in the next day and had several channels. Thought it was weird to catch fish with no bait so I left it another night. Caught more fish. Cleaned them, opened their stomachs... and found them full of snails. Checked the line and it was covered with snails. It was a self baiting system!

Channels also eat mulberry. Have had some great fishing under an overhanging mulberry tree on the creek.

Catscratch Good information about catfish eating smails. Did you happen to get a picture of those snails?

Sorry, didn't even think to take pics. If you’re interested I could try to get some pics the next time I'm out there for ya. Just let me know, and if you do want pics specify what you'd like to see exactly.

Catscratch - yes if the same snails are present collect a couple of the larger ones. Get a picture of top and bottom sides with a ruler for measurement comparison. If you can't post pics here on the forum then PM me and I will give you an email address to send the pics to me. I am interested in looking up the names of those snails that catfish were capable of eating. Also how big were the CC that ate the snails.

Going to be out of town until next week. I'll try to remember when I get back!

They were 2-6lb fish. Bellies full of snails when we'd clean them. It's been many many yrs since I ran a line in his pond.