Creeky Mollusca & Floating Vernal Snails

[Fred Schueler]

Everyone,

Our thanks right now is mostly that Aleta's over-active parathyroid
gland has been excised (Yes, Virginia, this involves carefully slitting
her throat), and she's recovering (a long letter about this is
available), and we're trying to get out and assess the consequences of
the drought for mussels and aquatic snails.

At the County Road 20 bridge over Kemptville Creek there are gravelly
bars above and below the bridge, which are exposed when the water is
low, and I ventured out onto the downstream bar, and found the bar and
mud generously sprinkled with snail and Fingernail Clam shells. I
gathered some of these up, and the one place where they were a bit
concentrated - the main excitement the abundance of the elongate
Stagnicola reflexa snails - a "species" we'd found in a few diverse
habitats before last spring, but which we're now finding is abundant in
Kemptville Creek right around home. The only Unionid was a lovely fresh
Lasmigona compressa pair.

I've already submitted this abstract -

Schueler, Frederick W., 2025. Floating Vernal Snails: summer studies of
species & mortality in seasonal waterbodies. ABSTRACT: Triggered by an
interest in the distribution of Aplexa in eastern Ontario vernal
wetlands, I have begun taking dry 20 litre samples of vernal pool
bottoms, mixing them with water, and floating snail shells out of them.
Preliminary results are that Aplexa is more widespread than expected,
that no live snails revived to attach to the bins the soil was soaked
in, and that the huge numbers of juvenile shells suggest that the snails
reproduce until the water is gone, and then survive if adult and die if
juvenile. Platform presentation at 6th Biennial Canadian Freshwater
Mollusc Research Meeting, 4-6 Nov 2025, Canada Centre for Inland Waters,
Burlington, Ontario.

- and I got two more samples for this project, from the
sometimes-flooded wetland on the curve between the bridge and the
Bishops Mills Cemetery, and then a sample from the pond in the Chorus
Frog wetland at the foot of Hares Hill Road (where the pond has what
looks like a long-leaved Juncus, and is surrounded by metre-tall Grass
and a glowing horizon of Frangulous Buckthorn, pierced by dead Ashes).

Stand by for more catching-up e-mails, now that Aleta is through her
surgery,

hoping everyone has plenty to be thankful for,

fred.
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Frederick W. Schueler & Aleta Karstad
Fragile Inheritance Natural History - https://fragileinheritance.ca/
2024 annual letter: https://clt1233162.bmeurl.co/11E63979
6 St-Lawrence Street Bishops Mills, RR#2 Oxford Station, Ontario K0G 1T0
on the Smiths Falls Limestone Plain 44.87156° N 75.70095° W
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