Frogs, crabs and toe-clipping

25 April 2018

Is clipping toes for DNA samples unnatural?

Procedures involving field sampling of many vertebrates require ethical clearance for ecologists wishing to collect genetic samples for DNA analysis and involve an increasing number of different sampling techniques. A growing number of choices of sampling techniques require researchers to re-examine procedures which have traditionally been accepted without question.

The practice of amphibian toe clipping is controversial. The impact of toe clipping on anurans is likely to differ with their life-history and studies on performance may provide better indications on the effect of clipping different toes. Buccal swabbing provides logistical difficulties and requires more resources for extraction of DNA.

Sampling of tadpoles is likely to introduce bias in the example given for population genetics of anurans, although there may be good reasons for using this technique to acquire genetic material in other circumstances. 

The majority of researchers need to provide sufficient information to convince an institutional ethics committee of their need to conduct ecological sampling. With respect to amphibians, we require more studies on populations using DNA to inform conservation decision making. Toe clipping of adults will represent the best current method for obtaining tissue samples for the majority of studies, as well as providing extra tissue which should be placed into tissue banking facilities for future studies.

One argument against toe-clipping is that it is unnatural. Recently, I found a pond full of frogs and crabs that made me think again about this. 

Show me a population of frogs which have had their mouths naturally buccal swabbed.

  Frogs  Lab  Xenopus

Low to High in South Africa

22 April 2018

From low to high, a search for extreme African clawed frogs

Had a great time in the field at some extreme sites in South Africa with Honours project student, Carla Wagener. 

We started low, trapping in sites within the iSimangaliso Wetland Park. There we were setting traps in shallow muddy pools with warm water, while lots of animals looked on.

Then we got high at the amazing Royal Natal National Park. We climbed up to 3100 m asl, and set traps and searched in the icy river waters. 

Sadly, we only managed to get crabs in our traps, but we found a whole lot of frogs at 2000 m that Carla will use in her project. We'll have to return to the Drakensberg another time to get the highest platannas in South Africa.

Now Carla has to use the frogs to do her experiments. More news on how this progresses here on the blog.

  Frogs  Lab  Xenopus