Posted by: salamandercandy | March 30, 2007

Rana waifromi?

I’m planning to collect toe clips from frogs in the Midwest this spring, including from the plains leopard frog, Rana blairi. I’ve been doing preliminary work with two dried up specimens of R. blairi that were shipped to our lab years ago by a commercial frog supplier. I used these specimens to optimize my PCR conditions and conduct some basic genetic analyses, but I need more samples to assess genetic variation within this species. In addition to my planned field season, I have been contacting museums and other herpetologists for previously collected specimens, and I was excited to receive the first of those not long ago.

As I began to study these new specimens, I soon realized that they were genetically quite distinct from the two dried up frogs in our lab. This prompted me to scrutinize our two lab samples a little more closely, and I discovered that they are, in fact, not R. blairi. They appear to be southern leopard frogs, R. sphenocephala, or possibly some sort of weird hybrids. Remember, these frogs were raised by a commercial supplier who keeps several species of frogs, and it appears that these two frogs were incorrectly identified as pure R. blairi. Of course, I can’t rule out that somehow they got mislabeled after they arrived in our lab.

Many biologists depend on specimens collected and identified by someone else, and this involves a great deal of trust. You have to believe that the data someone gives you are valid, or you can’t use them. Too much trust can lead to problems, though, as I just learned the hard way. Whenever possible, scientists should independently verify that their samples are what they think they are.

Fortunately, I shouldn’t have to change my field season itinerary too much. It looks like R. blairi will still be a good species to target for my study, even though everything I thought I knew about R. blairi genes is wrong. But I need to hurry up and study the putatively real R. blairi samples some more before I make my final field work plans.


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