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Having fun at the 21st European Congress of Herpetology

08 September 2022

Great to see Xenopus people meeting at the 21st European Congress of Herpetology

This year's European Congress of Herpetology is being held in Belgrade, and there were lots of Xenopus talks!

From left to right: Felix Deiß, Anastasia Regnet, Dennis Rödder, Nicholas Wei Cheng Tan, Natasha Kruger and Philipp Ginal

Among these were Dr Natasha Kruger presenting work from her PhD on a Xenopusreciprocal exchange experiment with tadpoles:

Kruger, N., Secondi, J., du Preez, L., Herrel, A. & Measey, J. (2022) Is there no place like home? Response of African Clawed frog tadpoles to novel environments

 and Philipp Ginal talking about his recent work on modelling the difference between adult and tadpole time in Europe:

Ginal, P., N. Kruger, L. Araspin, M. Mokhatla, J. Secondi, A. Herrel, J. Measey & D. Rödder (2022) More time for aliens? Performance shifts lead to increased activity time budgets propelling invasion success. 

I'm happy to say that both papers are in press, and you can read them here (even if you didn't see the presentations!).

  Lab  meetings  Xenopus

Innovation Talent Cultivation Forum

06 September 2022

S&SE Asian UN Innovation Talent Cultivation Forum held at Yunnan University

It seemed very far away as I sat in my Stellenbosch office and delivered a presentation to the S&SE Asian UN Innovation Talent Cultivation Forum held at Yunnan University. 

At the time, I was not aware that I was delivering a keynote speech - although that is how it was reported:

Subsequently, the talent to be signed, including Zhang Shoudong, research assistant professor of the Chinese University of Hong Kong, Hans J. De Boeck, senior researcher of the University of Antwerp in Belgium, and John Measey, professor of the University of Stellenbosch in South Africa, gave keynote speeches, respectively. 

It is always good to participate in such meetings - although it is hard to know exactly what the outcome is. 

Measey, J. (2022) Rapid evolution in an invasive species. S&SE Asian UN Innovation Talent Cultivation Forum, Yunnan University, 6 September 2022

  Lab  meetings

Reciprocal exchange of tadpoles

23 August 2022

Tadpoles in a reciprocal exchange experiment

I have long admired my botanist friends who are able to pick up their study organisms and move them to any climate they like and see how they grow. The effect of climate on animals (including frogs) has been well established, but very few researchers have taken the opportunity to use reciprocal exchange experiments (keeping one population at home while moving the other to a new environment, and vice versa) to investigate the effects of climate on tadpoles. The study design is particularly appealing as for two populations you get results both in their home and away climates. This allows you to compare directly how they have fared in both situations - although I admit that the four way comparisons take time to get used to. South Africa is very unusual in that it has two completely different climates that mean that African clawed frogs (Xenopus laevis)  from the southwest breed in the winter (winter rainfall), while those in the northeast breed in the summer (summer rainfall). 

Dr Natasha Kruger conducted this experiment as a part of her PhD studies at the CIB in Stellenbosch University and (jointly) in the University of Lyon I. The results, published today,  are really interesting.

In the figure above, you can see the number of tadpoles that metamorphose in each of the treatments. The graph in the top left shows that when winter animals (blue line) are moved to the summer rainfall zone , their timing of climax is very similar to that of animals that originate there (red line). However, the bottom left graph shows that in the reciprocal venue, tadpoles from the summer rainfall zone climaxed much earlier. But they did so at a cost. In the figure below (bottom left), you can see that survival of these summer tadpoles in the winter rainfall zone was the lowest.

Read the paper to get more insights on how this reciprocal exchange experiment allowed Natasha to determine that the causes for the differences are both plastic and adaptive.

Kruger, N., Secondi, J., du Preez, L., Herrel, A. & Measey, J. (in press) Phenotypic variation in Xenopus laevis tadpoles from contrasting climatic regimes is the result of adaptation and plasticity. Oecologiahttps://doi.org/10.1007/s00442-022-05240-6 

  Frogs  Lab  Xenopus

Asian Spiny toads at home in Vietnam

20 August 2022

Getting data from Asian Spiny toads in Vietnam

Back in January this year, MeaseyLab postdoc, Andrea Melotto, finally made it to Madagascar to collect data from an invasive population of Asian Spiny toads, Duttaphrynus melanostictus.  In Madagascar, Andrea performed a standard set of morphological, performance and behavioural traits with toads from the invasion core and expanding invasion front. Now Andrea has made it to Ho Chi Minh City in Vietnam, thought to be the site from where the Malagasy toads originated. There, Andrea is working with Dr. Dao Tran from University of Science-Ho Chi Minh City. 

The toads are abundant in and around the city, and are a regular sight sitting on the lily pads of water features. 

Andrea measures a recent capture while Thu enters data on the laptop.

Khoi enters data on the laptop for the second trial while Thu chases a toad down the racetrack and Phi videos the session. 

Measuring behaviour at night means working under red lights and using CCTV to record how the toads interact with their environments.


Brackets can be tricky

18 August 2022

The problems with brackets

Citations use brackets, and brackets are also used for other parts in writing. The problems with brackets often come when trying to combine citations that have brackets with the other parts of writing that also need the brackets. This is compounded when trying to do all this in citation software when you don’t have complete control over it.

Most citation software allows for flexibility of how you will use your citation. In the above examples we have seen the full citation, a version where just the year is included in the brackets, some text occurs before (prefix) or after (suffix) the citation within the brackets, or even a combination of these:

  • The classic: (Measey et al., 2016)
  • Omitting the authors: Measey et al. (2016)
  • Using a prefix: (e.g. Measey et al., 2016)
  • Using a suffix: (Measey et al., 2016: 976)
  • A combination of the above: Measey et al. (2016: 976)

Citation software handles producing these different ways by omitting the author, adding a prefix, or adding a suffix, respectively. However, the default will be to use the classic version, and you will need to alter this to one of the others in the software as you are citing it (i.e. as you add it to the document).

It is very common that people simply don’t know how to do these different ways of citing within their citation software. The easiest is to look up “how to add suffix” or whatever it is that you want to do in the respective manual or in your search engine. The result of not being sufficiently skilled in your citation software, is that you end up with confused text - and usually a surfeit of brackets. The examples below are all mistakes that I regularly see in theses and manuscripts:

Measey et al. (Measey et al., 2016) found that the impact of invasive amphibians is comparable to that of birds and mammals.


Invasive amphibians have some serious impacts on their recipient environments (e.g. Measey et al. (2016)).

Invasive amphibians have some serious impacts on their recipient environments (e.g. (Measey et al., 2016)).

The above examples are obviously wrong (i.e. obvious to an examiner or reviewer), and immediately suggest that the writer hasn’t invested enough time in mastering the citation software, or isn’t aware that what they have produced is incorrect. I’d encourage you to take the time to correct these kinds of errors in a timely manor, or at least before submitting your thesis or manuscript.

Avoid back to back bracketing

It is better to combine information into one set of continuous brackets instead of having back to back sets of brackets. You can do this by using a prefix or a suffix as below:

Some invasive amphibians have been investigated insufficiently compared to their impact (e.g. Asian common toads: Measey et al., 2016).


Instead of back to back bracketing as follows:

Some invasive amphibians have been investigated insufficiently compared to their impact (e.g. Asian common toads)(Measey et al., 2016).

If you must have brackets nested within each other (and I would argue that this is very unusual), then rather use different types of brackets, such as square brackets inside round brackets. But make sure that you do this consistently throughout your thesis or manuscript.

  Lab  Writing
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