A session dedicated to the Guttural Toad (Sclerophrys gutturalis)

The Conservation Symposium (1-4 November 2021) had a special session on the morning of 4 November 2021 where five MeaseyLab members presented their work on Guttural Toads. Because these presentations were recorded ahead of time, we are able to share them for your interest in a playlist here.

The humble guttural toad (Sclerophrys gutturalis): Lessons of plasticity and adaptation following invasion: John Measey

Introduction of guttural toads (Sclerophrys gutturalis) produces marked shifts in the endemic western leopard toad (Sclerophrys pantherina) gut microbiome: Carla Wagener

Does urban adaptation enhance invasiveness? A case study of tadpoles of a successful invasive amphibian: Max Mühlenhaupt

Conqueror toads: Comparing behaviour, performance and competitive potential in a successful invader and its native congeners: Andrea Melotto

An army marches on its stomach: Diet composition and prey preference of guttural toad (Sclerophrys gutturalis) populations along a native-invasive and natural-urban gradient: Sam Peta

The session was well attended with 140 people online. You may recognise some of the people below who showed up to face the questions...

Catch Xenopus in the Matroosberg

Although we had already collected African clawed frogs ( Xenopus laevis ) at 3,300 m asl in Lesotho (see here), at 1650 m asl in Sutherland (see here), these only represented two of the clades in the region. In order to get animals at high altitude from the southeastern clade, we needed a high altitude site with African clawed frogs. Happily, the areas around Matroosberg are at 1,300 m asl, and we managed to find frogs at the farm and in a mountain stream.

The stream water is a deep 'tea brown' from the phenols that come from the fynbos in the mountain catchment. The pools in the stream were several meters deep. That's a long way down for a trap to sit. 

As you can see, we missed one frog as it escaped from the trap as we pulled it from the water. But there were more than enough animals captured to complete the sample size that we were looking for.

African clawed frogs from the Southwest altitudinal transect

Any attempt to collect animals across an altitudinal transect is going to involve going high and low. Getting high, often involves getting cold, and that's exactly what we got when we made our highest collections at Sutherland. In driving rain, and temperatures below 10 C, we managed to get a good sample of frogs from ~1600 m asl, just outside of Sutherland town. 

From there it was down hill. We collected tadpoles using a colander in Prince Albert, drove through the Swartberg Pass, and finally ended up in the beautiful Nature's Valley where we captured the first ever record for Xenopus laevis   from the area, as well as completing our sampling and our transect. At every stop, we unpacked huge suitcases to form a fully functioning lab to make sure that the samples were tip top.

The research was driven by Boissinot Lab postdoc Dareen Almojil, who will stay on in Stellenbosch for some more sampling. Also featured is the very able Sandra Goutte, and of course, the Boissinot Lab boss, Stephane Boissinot.

Read about the Northeastern transect that was completed in March 2021 with Laurie Araspin and Carla Wagener here.

We look forward to seeing what comes of these samples once they are sequenced back in NYU-AD!

A talk for Stellenbosch University library

I was invited by the library at Stellenbosch University give a talk for their Open Access week. The theme was UNESCO's "It Matters How We Open Knowledge: Building Structural Equity."

As this theme fitted perfectly with my forthcoming book "How to publish in the Biological Sciences", I provided a talk giving a brief outline of the state of publishing. 

Growing up in a new world

In a new paper published in Neobiota, Max Mühlenhaupt and colleagues bring tadpoles from invasive and native (both urban and rural) populations of the Guttural Toad (Sclerophrys gutturalis) into a common garden. You may remember the exploits of Max back in late 2019 and early 2020 (if not, then you can read about them here, here and here).

Max looked at lots of traits of the tadpoles as they developed over time. This included morphology swimming performance and developmental rate. What he found is that animals from all populations were identical morphologically and their performance did not diverge. However animals from the invasive population in Cape Town developed significantly more slowly.

In the video clip below, you can see how Max stimulated the tadpoles to perform. From videos such as this, he was able to measure swimming performance of individuals.

Although the COVID-19 pandemic interrupted the end of this experiment, we expect that the slow development of tadpoles from Cape Town would have resulted in their larger size at metamorphosis. This is yet another example of adaptation in an extremely short period of time. Guttural Toads were first discovered in Cape Town in the year 2000. Just under 20 years from when Max started his experiment.

Read more here:

Mühlenhaupt M, Baxter-Gilbert J, Makhubo BG, Riley JL, Measey J (2021) Growing up in a new world: trait divergence between rural, urban, and invasive populations of an amphibian urban invader. NeoBiota  69: 103–132. https://doi.org/10.3897/neobiota.69.67995