Herpetology: Amphibians

Ever heard of herpetology? Me neither, but Google tells me that it’s the study of amphibians and reptiles which I suppose I assumed must be thing but never really thought to find out more about it; I’m stuck in a microbiology bubble! So in a series of two blog posts I’ll give you a brief low down on herpetology and what the herps (a common term for a herpetologist apparently). Let’s start with amphibians!

Frogs and…

Admittedly the only type of amphibian that I can think of is a frog which is shameful and I feel like my description of what constitutes an amphibian dates back to pre-GCSEs (maybe year 8?) which is equally juvenile. As most people may know from their school days or work, in taxonomy there are different levels of classification used to put animals into metaphorical piles and from memory the order in which these levels go, from broadest to narrowest, is: Kingdom, Phylum, Class, Order, Family, Genus and Species. This may be quite general and as I’ve found out in microbiology, the species category is nowhere near the end of the classification tree! Amphibia is a class and this is split into 3 main orders: Anura (frogs and toads), Caudata or Urodela (newts and salamanders) and Gymnophiona or Apoda (caecilians; described as ‘large earthworms’ by AmphibianArk.org).

All these animals are cold blooded, rely on their environment to regulate their body temperature and live in moist environments. They go through a metamorphosis process as they mature from juvenile to adult which reminds me of all the pictures in school textbooks of tadpoles with one frog leg progressing to frogs with tails. An interesting fact that I came across via Sandiego Zoo is that these animals absorb nutrients and breathe through their skin! This may be common knowledge for most scientists but it is definitely news to me!

So what do amphibians do apart from hopping around and lurking in ponds?

Despite the bad press that this group of animals may get from the stories that come with cane toads, they are actually quite important in maintaining a balanced ecosystem. The fact that they eat insects means that they help agriculture and can minimise the spread of diseases like malaria. Their skin contains chemicals that protect them against bacteria and viruses which are claimed could be used in research to possibly cure AIDS. Unfortunately, they are among the first animals to be affected by changes in their environment. Amphibian Ark aptly describes them as ‘canaries in a coal mine’ which infers that their declining numbers are a warning to humans of what could happen to us in the future, especially with climate change!

This seemingly fragile class of animals are being hit from all angles, especially from an intracellular parasitic chitrid fungus called Batrachochytrium dendrobatidis. This lengthily named fungus has thankfully been abbreviated to Bd to spare us from having to say it really quickly in a conversation. Most chitrid fungi live as saprophytes on dead decaying matter but this species decided that it wanted to live in the skin cells of amphibious invertebrates. And why wouldn’t it? Amphibian skin is mostly moist and full of nutrients! For the victim though, it results a thickening of the skin and because amphibians absorb water and nutrients through their skin I interpreted this to mean that the fungus essentially starves its host to death. Grim. Unfortunately, it has a very broad host range in terms of amphibian species and could spell doom in the form of mass extinction! Find out more in the paper by Hudson et al (2016).

What’s hip and hoppenin’ with the herps?

I thought that a browse through the current research in herpetology section of Nature would throw up some interesting papers and I wasn’t disappointed. Amphibians are a hot topic in studies that analyse ‘asymmetric competition over calling sites in two closely related treefrog species’ (Borzée and Jang, 2016) and ‘experimental evidence for beneficial effects of projected climate change on hibernating amphibians’ (Üveges et al, 2016). It seems that this area of expertise is as broad as any other with papers on evolution, genetics and fossils to name a few topics that cropped up in the list.

It seems that whenever there is a problem with something in the world there is a band of people ready with sampling kits and brains full of knowledge to try and solve it, herpetology is obviously no different and these perhaps lesser known scientists are dedicated to making sure that this vulnerable group of animals doesn’t go without a bit of help.

I know I have only just skimmed the surface of this amazing subject but I hope I’ve given you a taste of the area so that you might want to know more. If you enjoyed this then stay tuned for another brief instalment of this area where I’ll look at reptiles and where they fit into this world of science that we live in.

References – Webpages

References – academic papers

  • Borzée, A., Kim, J.Y. and Jang, Y., 2016. Asymmetric competition over calling sites in two closely related treefrog species. Scientific Reports6.
  • Hudson, M.A., Young, R.P., Jackson, J.U., Orozco-terWengel, P., Martin, L., James, A., Sulton, M., Garcia, G., Griffiths, R.A., Thomas, R. and Magin, C., 2016. Dynamics and genetics of a disease-driven species decline to near extinction: lessons for conservation. Scientific reports6.
  • Üveges, B., Mahr, K., Szederkényi, M., Bókony, V., Hoi, H. and Hettyey, A., 2016. Experimental evidence for beneficial effects of projected climate change on hibernating amphibians. Scientific reports6.
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