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Natasha defends her PhD thesis (unofficially in Stellenbosch)

14 February 2020

Natasha defends her thesis

Doing a thesis defense is always a bit nerve wracking, but imagine if you had to do it twice? Luckly, for Natasha, it turned out that she did only have to defend her thesis once, but after we'd organised a defense in Stellenbosch, we decided to go ahead with the defense as a good practice for the real defense in Lyon. Whether or not it was actually going to be a defense seemed to be beyond our control. The faculty flip-flopped several times on the issue. 

Then, at the last minute it looked like even the dry run wouldn't happen as we were forced out of our building for a small fire on the first floor.

We got back into the department shortly after 13h00, when the defense was due to start. We had a diminished audience as many people had disappeared during the evacuation, but all of the important people were there to listen.

In time honoured fashion, after the defense, the lab all went down to the pub to celebrate.

  Lab  Xenopus

Mac's PeerJ paper is published

22 October 2019

Effects of temperature on the physiology of three African frogs

Some of you will remember Mohlamatsane ‘Mac’ Mokhatla and his work on three species of widespread African frogs: the principally aquatic African clawed frog (Xenopus laevis), stream-breeding common river frog (Amietia delalandii), and the largely terrestrial raucous toad (Sclerophrys capensis). Keen readers will remember that one of Mac’s species changed its name three times during the course of his PhD (see here)! Well, some of that work was immortalised today in a paper summarising the physiology work that Mac did on these three frogs. 

While there’s been quite a lot of work done on the physiology of frogs, most of these studies are done in the northern hemisphere on temperate frogs with similar biologies. Mac chose three very different species: platannas that spend most of their time in water, toads that are mostly terrestrial, and river frogs that spend much of their time jumping from land to water and back. 

The results suggest that vapour pressure deficit (an important trait for frogs that need to remain hydrated) better predicted rates of evaporative water loss than ambient temperature in toads and river frogs. 

Read more about Mac's thesis here or read more the paper here:

Mokhatla M, Measey J, Smit B.2019.The role of ambient temperature and body mass on body temperature, standard metabolic rate and evaporative water loss in southern African anurans of different habitat specialisation.PeerJ7:e7885https://doi.org/10.7717/peerj.7885



  Frogs  Lab  Xenopus

Jean Secondi visits the MeaseyLab

18 October 2019

Jean Secondi visits from U Angers

Natasha Kruger has spent the past 3 years spending Summer in South Africa, and then spending the next Summer in Angers with Jean Secondi. We’ve featured some of this travelling on the MeaseyLab blog before (see here and here), and also some of the work that Natasha produced (see here). 

Finally, after 3 years of waiting, Jean visited Stellenbosch to familiarise himself with the native habitat ofXenopus laevis(which he knows all too well from years of studies on the invasion in France), to spend some important time working with Natasha, and to attend the African Amphibian Working Group (AAWG) in George. 

We took Jean along on a long weekend to our long term monitoring site for the Cape Platanna in Kleinmond. Sadly, we didn’t find any African clawed frogs in their usual hauntings and all of the Kleinmond sites that normally containedXenopus gilliwere completely dry. We did however, manage to sample a site with Cape platannas in Betty’s Bay. We even found one animal that Andre de Villiers had marked way back in 2014!

It was great having Jean visit the lab, and we really hope that he also enjoyed himself and will take good memories of South Africa back to Angers. We are also really looking forward seeing him again during our visit to Lyon next February to attend Natasha’s defense!

  Frogs  Lab  Xenopus

18th AAWG in George

08 October 2019

18th African Amphibian Working Group (AAWG)

My first AAWG was back in 1996, when I was still finishing my PhD at Bristol University. It was the only conference that I attended during the entirety of my PhD studies, and it happened in Bristol - yes, that exotic far flung location that I had been saving myself up for…

This year, the 18th AAWG was held in the town of George, in the Western Cape, South Africa from 7-8 October 2019. The venue was the Garden Route Botanical Gardens, George. George is close to the Outeniqua Mountains, and is the home to a range of interesting frogs includingBreviceps fuscus,Afrixalus knysnae(pictured above) andHeleophryne regis.

We had a lot of fun listening to lots of different talks about amphibians from all over the continent. The CIB was well represented with talks from Anneke Schoeman, Natasha Kruger, John Measey, Mac Mokhatla and Sarah Davies (see pic!).

There were a bunch of talks from the MeaseyLab. See below for titles:

Talks:

Natasha Kruger, Jean Secondi, Louis du Preez, Anthony Herrel, John Measey 2019. The local adaptation of development and survival of nativeXenopus laevistadpoles in different climatic regions in South Africa.18th African Amphibian Working Group, George, South Africa.

Mohlamatsane Mokhatla, Dennis Rödder, John Measey 2019. Using physiology and performance to predict climate driven distribution range shifts in three temperate African anurans species: a hybrid modelling approach. 18th African Amphibian Working Group, George, South Africa.

Sarah Davies, Dean Impson, Jonathan JA Bell, Clova Jurk-Mabin, Marco Meyer, Chandre Rhoda, Louise Stafford, Kirstin Stephens, Mfundo Tafeni, Andrew A Turner, Nicola J van Wilgen, John RU Wilson, Julia Wood, John Measey 2019. Coordinating invasive alien species management in a biodiversity hotspot: The CAPE Invasive Alien Animals Working Group. 18th African Amphibian Working Group, George, South Africa.

Francois Becker, Jasper Slingsby, John Measey, Krystal Tolley, Res Altwegg 2019. Searching for rare species and determining their absence for conservation applications. 18th African Amphibian Working Group, George, South Africa.

John Measey 2019. Rapid adaptation of an invasive African toad:Sclerophrys gutturalis.  18th African Amphibian Working Group, George, South Africa.


Natasha's Conversation piece

22 September 2019

Do you know whether it's friend or fo?

When alien species are moved to a new environment, they have a whole new set of predators and prey to become accustomed to. To determine whether the novel sensory inputs are predators or prey is very important, as this can translate to life or death. While adult frogs have sophisticated sensory organs, their tadpoles' senses are less developed but recognising predators is still very important.

In this popular piece for The Conversation, Natasha Kruger explains how African clawed frog, Xenopus laevis, tadpoles reacted when they were exposed to smells from different species in France. Natasha explains how familiarity with some of the smells, like predatory diving beetles, might be more famliiar than others, like crayfish which are not-native in sub-Saharan Africa.

What did the tadpoles do? 

You can read Natasha's explaination in this excellent popular write-up.

Natasha's PhD has been investigating the role of tadpoles in the invasion of the African clawed frog, Xenopus laevis. We're looking forward to lots of revelations of how tadpoles differ from their adult forms. 

Kruger, N (2019) Invasive tadpoles can recognise potential predators in new environments. The Conversationhttps://theconversation.com/invasive-tadpoles-can-recognise-potential-predators-in-new-environments-119673 

  Frogs  Lab  Xenopus
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