Montenegro Slugfest
On the role of amateurs in taxonomy
In 2019, a group with participants from Italy, the Netherlands, Serbia, South Africa, and the United States discovered a new species of giant keelback slug in Montenegro named Limax pseudocinereoniger. They encountered it beneath rock overhangs along a narrow stretch of Europe’s deepest gorge, the Tara Canyon. Fully extended, the slug measures a respectable 20 cm in length. Similar in external appearance to another species inhabiting Tara Canyon, Limax cinereoniger, the two were concluded to be distinct species based on a 10% difference in their DNA barcodes and differences in internal reproductive structures.
Beyond an unexpected gastropod, and giving new meaning to slugfest, I found this story interesting for reasons that leave no slime trail. It involved citizen scientists rather than professional malacologists. Amateurs discovering species is not new and there have always been amateur taxonomists; some quite good, others, not so much. By some estimates, sixty percent of new species described from Europe each year are named by amateurs. With tens of thousands of extinctions each year, species exploration needs all-hands on deck with the proviso that efforts move the inventory of species forward.
Overall, amateur taxonomy has unfortunately earned its bad reputation. There are thoughtless collectors who seek out and further endanger rare species. Collectors who chase tiger beetles across county lines so that they can claim a new county record. And worse, amateur taxonomists — inadequately educated and trained, and sometimes unethical — interested in showy groups, like orchids or tarantulas, who are more eager to see their name in print associated with a new species than working to high standards. As a result, mere genetic variations are given species names. It then takes time of competent taxonomists to sort things out, time better spent describing actual species and keeping classifications up to date.
With so much taxonomy to do on a planet with millions of undescribed species, it is taxonomic malpractice to clog-up the system with worthless descriptions. There are no substitutes for education and experience. I once reviewed a manuscript describing a remarkable new species in a genus that I happened to know well. As it turned out, it was a common species. The only thing remarkable about it was that it had been misidentified to genus. The lesson is that you need to know, and respect, your limitations. Taxonomists spend years becoming an authority on a particular taxon, and for good reason. It takes time and dedication to master the theory and practice of taxonomy, not to mention several centuries of accumulated knowledge. I once had a fifth-grade student write to me asking how I knew when I had found a new species. My reply to her was that it’s simple. All you have to do is learn every species named since 1758 in the group it belongs to; if it is not one of them, then it’s new.
The trip to Montenegro was organized by Taxon Expeditions, an organization that offers the public a chance to take part in scientific discovery. This takes the well-established concept of ecotourism to the next level. Such citizen expeditions, led by taxon experts to areas suspected of hidden species diversity, could become a great way to include people in the adventure and intellectual excitement of species exploration. I like it.
I resent the word amateur used as a pejorative. Amateur literally refers to something done out of love. The very best taxonomists have always been inspired by love for the species they study, whether they are paid for their efforts, or not. I am personally more suspicious of mercenary taxonomy than amateur, done in pursuit of grant money or recognition rather than pure curiosity.
Pearson, Hamilton and Erwin suggested that descriptive taxonomy as we know it is becoming a thing of the past. They expressed the opinion that it will not be done, for the most part, by professionals in the future. In their view, the category of professional taxonomist will shrink to a handful of individuals who will “use cyberspace and a wide range of skills to recruit, train, and provide direction for expert amateurs, young students, parataxonomists, the general public, and governments.” Looking at the decline in prestige, jobs and grants for doing taxonomy, it is easy to see the trend they saw. But that does not make it right, desirable, or inevitable. Descriptions involve more than writing down what specimens look like. Done to professional standards, they are theory-rich, evidence-informed, explicitly-testable hypotheses as rigorous and sophisticated as those of any other science. Taking nothing away from fantastic opportunities for amateurs to participate in species exploration, there will always remain the need for professional-level taxonomy.
No one expects astronomers to reduce their profession to a few individuals cheering on an army of amateurs with eyes glued to telescopes. Astronomy, like taxonomy, is a rigorous science. It requires a deep dive into theory and a lengthy apprenticeship to master. As a serious science, it cannot be duplicated by amateurs, no matter how talented, well-intentioned and organized. The fact that amateurs can and do make important discoveries in no way diminishes the need for professional astronomers to advance the field. Just as our innate curiosity drives us to explore and understand the Universe, it demands that we explore, also, the diversity and history of life. Understanding and their relationships is one of science’s great challenges and deserves serious, professional pursuit.
The argument that taxonomy can be handed off to amateurs assumes that taxonomy is a lesser science. Considering the rate at which species are going extinct, this is no time to ignore or reduce scientific rigor in taxonomy. A recent theoretical revolution in taxonomy has made its science more rigorous than ever, gains that ought not be sacrificed. It is a great strength of taxonomy that citizen scientists can be included in species exploration. But taxonomy, as an independent, fundamental, curiosity-driven science, remains as important to our understanding of the world as astronomy, chemistry, or physics and must be led by professional scientists and great institutions.
Further Reading
Pearson, D.L., Hamilton, A.L., and T.L. Erwin (2911) Recovery plan for the endangered taxonomy profession. Bioscience 61: 58-63.
Schilthuizen M, Thompson CG, de Vries R, van Peursen ADP, Paterno M, Maestri S, Marcolongo L, Esposti CD, Delledonne M, Njunjić I (2022) A new giant keelback slug of the genus Limax from the Balkans, described by citizen scientists. Biodiversity Data Journal 10: e69685.