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‘Prospect of existence’: Nameless grasshopper sparks taxonomic debate

  • Researchers’ failed attempt to describe a new-to-science species of grasshopper based only on photographs has prompted a debate over established taxonomic convention.
  • The grasshopper was photographed in northern Peru in 2008, and researchers from Croatia have since had their attempts to formally describe it rejected by journal after journal.
  • In response to what they saw as an “arbitrary” process, the researchers wrote a paper on the challenges of describing a species from only photographs, arguing that conventions should change in an era of biodiversity loss.
  • “If a living specimen is never found, it will remain a curiosity, suspended between existence and the prospect of existence,” said lead author Niko Kasalo.

What’s in a name? The curious case of a nameless grasshopper will tell you that there is more to a name than meets the eye.

To declare a species as new to science, scientists name and describe the plant, animal or other organism in a journal. But researchers say photographs were not enough for the scientific community to allow them to declare a new grasshopper in the Scaria family, a genus of groundhopper or pygmy grasshopper native to South America.

The scientists in Croatia and Italy have since published a thought-provoking paper in the Journal of Orthoptera Research on the species’ name — or rather, its lack thereof — calling on the scientific community to reconsider current taxonomic practices, especially in an age of mass extinction and rapid habitat loss.

This debacle dates back to 2008. That was when Roberto Sindaco, a professor at Italy’s Institute for Wood Plants and the Environment (IPLA by its Italian acronym), photographed an elusive yellow-and-green grasshopper deep in the rainforest of northern Peru.

His remarkable shots stayed buried within his photo archives for more than a decade before he uploaded them onto species data- and image-sharing platform iNaturalist.

Besides its unique and handsome morphology, the nameless Scaria is a unique example of a formal description without a name, says researcher Niko Kasalo. Image by Roberto Sindaco/iNaturalist.

It wasn’t until Josip Skejo, researcher at the University of Zagreb, chanced upon the photos on the site that this unassuming creature finally received due attention. It was unlike anything he’d ever seen before.

“This is maybe the most beautiful Batrachidein I have ever seen,” Skejo commented on iNaturalist. “Cannot identify it. What a beauty!” He added the grasshopper’s locality deepened the mystery as it resembled grasshoppers on the island New Guinea.

Skejo and his team then set about trying to verify its singularity, and subsequently advocate for its species status — a quest seldom undertaken with only photographic evidence.

“The first hurdle was identifying whether the species in the photographs really was a new species, and to which genus it belonged,” says Niko Kasalo, the lead author of the paper, also from the University of Zagreb. “The photographs were excellent, so we could see many important features which allowed us to place it in the [grasshopper] genus Scaria, but still, there were a few instances where we had to work really hard to be able to confidently describe what we were looking at.”

The second hurdle was to scientifically baptize the grasshopper by publishing their findings — a task that proved to be “unsurmountable in its simplicity,” Kasalo says. A few journals rejected the paper outright, and one editor told the team that their approach is “not right,” advising them to change it.

After months of rejections, Skejo and the team elected to make the nameless Scaria a martyr for the scientific community in order to reflect on the rules of taxonomy.

“We concluded that, while there is a good reason for being skeptical towards photo-based description, the process of choosing what is allowable and what is not is arbitrary,” Kasalo says.

A new grasshopper in the Scaria family. Image by Roberto Sindaco/iNaturalist.

Physical specimens are the gold standard for holotypes, the singular type specimen from which biologists describe an entire species. Besides allowing for the consideration of the specimen’s internal morphology and microscopic and genetic characteristics, a physical specimen, i.e. a dead body, also serves as a strong barrier against non-experts seeking to publish works based on superficial observations in the field.

Recommendation 73B of the International Code of Zoological Nomenclature (ICZN), the most widely accepted convention in zoology, states that a holotype specimen “known to the author only from descriptions or illustrations” is explicitly frowned upon. In other words, you’d need a body to prove the existence of Bigfoot.

Despite this, the team maintains that the ICZN recommendation acts as a suggestion, and is not listed as mandatory for good reason.

“It is better to see it as a framework that provides us with a common language, while also allowing a certain degree of freedom. The problem hides exactly in that freedom of interpretation,” Kasalo says. “So, the real question is what the scientific community will deem acceptable as times change.”

In a time of mass habitat destruction and increased technology (such as high-quality digital photographs), the debate over whether to change taxonomic rules has become more critical than ever.

The nameless Scaria grasshopper, for example, resides in one of the 10 most biodiverse countries in the world. It was also found in one of the 11 regions expected to experience more deforestation than any other by 2030, according to WWF.

Skejo and his team further cited the restrictions imposed in response to the COVID-19 pandemic, the time it takes to establish a close rapport with local researchers, and funding limitations as key reasons why attempts to look for a physical specimen of the unnamed grasshopper were unfeasible during the time of the research.

“Names and descriptions change in light of new findings,” Kasalo says. “You cannot use photographs to describe [some taxa like] nematodes, but that doesn’t mean that this approach is wrong for every taxon.”

Meanwhile, there’s sufficient evidence that “by the time a scientist collects, examines, and describes one new species, several more have gone extinct” before ever being known to humankind, according to a paper in Biodiversity and Conservation in 2009.

Regardless of the conservation status held by the unnamed grasshopper, the team asserts that legitimate photography-based descriptions should still be evaluated on a case-by-case basis.

“If a living specimen is never found, it will remain a curiosity,” Kasalo says, “suspended between existence and the prospect of existence.”

Citations:

Kasalo, N., Deranja, M., Adžić, K., Sindaco, R., & Skejo, J. (2021). Discovering insect species based on photographs only: The case of a nameless species of the genus Scaria (Orthoptera: Tetrigidae). Journal of Orthoptera Research, 30(2), 173-184. doi:10.3897/jor.30.65885

Stork, N. E. (2009). Re-assessing current extinction rates. Biodiversity and Conservation19(2), 357-371. doi:10.1007/s10531-009-9761-9

Smitch, J., & Schwartz, J. (2015). Deforestation in Peru. WWF. Retrieved from https://www.worldwildlife.org/magazine/issues/fall-2015/articles/deforestation-in-peru

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