NANFA-- Cold Tolerance of H. formosa
Fri, 7 Jan 2000 20:37:20 EST

With the warm winter here on the Gulf Coast, I`ve been doing some
"experiments" regarding the cold water tolerance of Heterandria formosa.

Innes list 55 to 85 degrees. Alelrod and Schultz say 50 to 90 degrees.

I now have found they can "tolerate" WATER temperatures in the low
40`s, as long as the change is GRADUAL!

Looking at the fishes northern distribution range...this looks about right.

However, clearly this is a sub-tropical species that "prefers" water
temps. much milder.(Check out the dots througout Florida on Freshwater
Fishes of North America 1980).

Any comments?

Rob Erhardt

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