Pond Frogs Didn't Survive

[Ted]

bullfrog needs deeper water in the winter , but yes they produce a antifreeze in their bodies also..Their glucose raises higher to keep them from freezing..

[UncleChester]

bullfrog needs deeper water in the winter , but yes they produce a antifreeze in their bodies also..Their glucose raises higher to keep them from freezing..

Bullfrogs aren't considered freeze tolerant according to any papers I've read. For example, http://www.units.miamioh.edu/cryolab...tanzoLee99.pdf mentions:

"Arnong the ranids, freeze tolerance has been demonstrated only in the most terrestrial species, the wood frog (Rana sylvatica), although it is likely that Palearctic brown frogs with similar habits (e.g., Rana arvalis; Kuzmin 1995) are also freeze tolerant."

I'd love to see any references you have, it could be a matter of degrees of 'freeze tolerance' if bullfrogs produce some level of cryoprotectants.

[Ted]

I'm not an expert,I went to google and typed in "do bullfrogs freeze in the winter?"..

[UncleChester]

I'm not an expert,I went to google and typed in "do bullfrogs freeze in the winter?"..

I'm by no means an expert either. I'm always up for learning something new and open to the possibility that I'm way wrong about just about anything.

I looked at the first couple of results from that google search and neither mention bullfrogs being freeze-tolerant. The first one How do frogs survive winter? Why don't they freeze to death? - Scientific American does mention the usual anti-freeze producing suspects Wood Frogs and Spring Peepers, the second just talks about Wood Frogs. Was there another link you found?

[Ted]

I'm kind of uncomfortable here,,I don't want to get in over my head,ok?..but what I really typed in was "does a bullfrog freeze?"...I found it on opinicon.wordpress....opinicon natural history..just below the graph but right above "conservation status"..

[UncleChester]

Sorry, I'm not trying to make you uncomfortable- we're just talking about some frog biology.

It never hurts to have the links you read on standby for when someone asks for more detail though. It looks like this is the one you had found: American bullfrog / Ouaouaron | Opinicon Natural History They mention that Bullfrogs aren't considered 'freeze tolerant', but have a few adaptations to help survive the cold.

The bit about higher glucose is interesting, and the paper referenced is freely available online Seasonal changes in the cardiovascular, respiratory and metabolic responses to temperature and hypoxia in the bullfrog rana catesbeiana Increased glucose doesn't mean they can handle freezing, or more importantly the extended periods of freezing that a few other species are known to take. The paper I linked to earlier was about Northern Cricket Frogs who produce large amounts of glucose when it gets cold but are decidedly incapable of taking much in the way of freezing. It would be interesting to know just what temperatures bullfrogs can handle and for how long, but honestly these kinds of studies are always a little depressing from the participants point of view.

Anyways, thanks for pointing me to the Opinicon blog, it has plenty of interesting stuff on it as well as piles of references.

[Ted]

Anything that survives the cold where I live has my respect..lol,the participants..yeah,they always have the last say,,actually this has been really great ,so thank you