Hello! I am Zann, now a Year 4 undergraduate at ASE, back with Part 2 of The Journey of Creating the Singapore Dung Beetles Species Checklist. A few months have passed since Part 1, so let me give a summary of what “Part 1” referred to. (Alternatively, read Part 1 in full here!)
My URECA (Undergraduate Research Experience on Campus) project is split into three parts – specimen collection, DNA barcoding, and morphological traits. In 2021, I worked together with my lab mate Yong Xu to carry out dung beetle sampling around Singapore (Read about how we collected our specimens here!), with the aim to bridge existing knowledge gaps of dung beetle distribution in urban areas of Singapore. We had then sorted our specimens by morphospecies, with the goal to later find out what these species are. This is where my project comes in – to create a species checklist, now with additional recent data to add to our database.
Under the supervision of Prof Eleanor Slade, I have since worked with PhD Student Ong Xin Rui and Project Officer Marx Yim to match names to these morphospecies and refined the sorting to be more accurate.
As part of my project, a species checklist was assembled from our newly-sampled specimens, and historical records which had been collated by Xin Rui. These historical records include, but is not limited to, specimens from the Lee Kong Chian Natural History Museum, the Global Biodiversity Information Facility (GBIF), NUS Repro Lab’s collections, our own lab’s collections, as well as other published and unpublished data sets. We would like to thank everyone who has contributed data, which undoubtedly made the species checklist more robust and enriched with information.
Imaging
I had several long days in the lab to take high-quality images of our dung beetles, but it was worth every minute to get these super up-close, HD pictures of our small (often <1cm) dung beetle friends!
Morphological Key
The next product of my project would be the species morphological key. This key aims to contribute to dung beetle studies in Singapore by having more consistent identification (when identification is based purely on morphology), and encourage citizen science by still keeping it simple and accessible to the public. Based on current feedback from our lab mates, we are still refining the species key – we are hoping to include more traits, make some clearer distinctions between morphologically similar species, and improve the organization of the questions.
Making the morphological key was like playing a spot-the-difference game like no other. Staring at dung beetles, trying to find the smallest details that could differentiate one species from another. Sometimes, it was easy, like recognizing the humongous Catharsius renaudpauliani from the much smaller Onthophagus species. Other times, it could be staring down the microscope, wondering if that ever-so-slight iridescence I’m seeing on the dung beetle is the result of an actual difference due to puncturing or structures on the beetle, or my eyes telling me it is time to take a break. Haha.
DNA Barcoding
Now, what about the DNA barcoding part of my project? In the past semester, I carried out DNA extractions for all ~890 of our recently collected dung beetles, by using tissue extracted from the right middle leg of each dung beetle (or one antennae segment, for larger species like Paragymnopleurus maurus or Catharsius renaudpauliani).
These DNA barcodes will allow us to:
1) Confirm species identity: This is especially important given the presence of species complexes, which are two or more species that may exhibit similar morphological traits (i.e. look the same)
2) Contribute DNA barcodes of dung beetles in Singapore to global databases: Dung beetles, despite their ecological importance, have been underrepresented in Southeast Asia in GBIF-mediated data. Our contribution of Singapore barcodes is thus crucial in filling this knowledge gap. (Find out more on why this is important here)
Unfortunately, we have had some delays in getting the DNA sequenced. However, the good news is that it is currently underway, and we are looking forward to getting back the sequences so that we can continue to move forward with the project. Look out for more updates from the TEE Lab! 😊
I have greatly enjoyed working on this project over the past year – I had gained experience in both fieldwork and lab work, and, in the process of making the species checklist and morphological key, started learning more about the taxonomic impediment for invertebrates like insects, the importance of streamlining and consistency in identification, and how much more that we may have to discover in this neglected field of taxonomy. With integrated taxonomic approaches like making use of DNA barcoding to confirm species identity, consulting taxonomists and building on existing knowledge of fellow dung beetle experts, we can slowly but surely bridge this gap and continue to add value to dung beetle studies in Singapore and Southeast Asia.
I am also happy to share that my work has also been acknowledged by fellow scientists, being awarded Regional Winner (Asia) in the Earth and Environmental Sciences category at the Global Undergraduate Awards 2022. To quote Prof Eleanor, I’m ecstatic that I could “get dung beetles recognized on the global stage!”, and highlight the pressing need to bridge the taxonomic gap in our knowledge amidst the global biodiversity crisis.
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Written by: Zann Teo