A REALLY COOL TURTLE

Most reptiles and amphibians in northern climates survive the winter by burying themselves in land or in the mud at the bottom of a pond below the ice level and achieving a torpid metabolic status pretty close to death. Almost all of their bodily processes are nearly shut down, and they even stop eating a while before their long rest so that there is no waste material in their colon lingering as a potential source of infection. If you were to dig up a herptile in its winter slumber, it would appear lifeless--at least upon casual observation.

The common snapping turtle (Chelydra serpentina), is an exception to the "total lethargy rule." While snappers generally follow the above procedures of hunkering down in the mud during the cold months and doing nothing, It is not unusual to spot some snappers in midwinter who are not sleeping with the fishes but who instead are actually swimming around in a pond underneath a sheet of ice. Although snapping turtles normally insert their head above water every few minutes to breathe (as they, of course, have lungs--not gills), a snapper in the northern USA may be sealed under ice for four or five months without the ability to take a single breath.

How do they survive? Well, a snapper can absorb a small amount of oxygen from the water through membranes in its throat and mouth in a process called "extrapulmonary respiration;" however, this procedure by itself is often not adequate to provide the metabolic needs of a moving turtle. The creative chelonian will then start burning sugar and fat in an inefficient anaerobic attempt aimed at avoiding oxygen utilization. This process builds up a lot of bad metabolites, such as lactic acid. It is believed by many learned guys that the turtle uses the calcium in its shell as a buffer against the excess acid.

We have had a couple of pet snapping turtles throughout the years (a choice not for everyone--remember they are called SNAPPING turtles). One of them, Arnold, would go in a pseudo-hibernating state each winter and would not feed from October to March. I could never figure out how Arnold knew when winter arrived, as he resided in a large tank in an interior room which had consistent artificial lighting and a consistent temperature all year round.

Oh, and remember how the sex of Nile crocodiles is determined by the temperature of the eggs? Ditto for snappers.