Monday, February 2, 2015

New Species off the Shelf

When someone discovers a species new to science, the species gets to be named! Exciting, right? Species get named through a formal process called species description. In a species description, the scientist has to describe how the new species looks and how it differs from all previously described species.

Luiz Rocha at the California Academy of Sciences started a fun discussion recently on the FaceBook group of the American Society of Ichthyologists and Herpetologists (ASIH). Prompted by a reporter, he was curious if any of the taxonomist's of the group had experienced discovering a new species, not from going into the field, but by finding it in a natural history collection.

Certainly, many species are found by going to unexplored places. But it turns out you can go to a place and grab a new species off the shelf. These places are natural history museums, such as the American Museum of Natural History in New York, the Field Museum of Natural History in Chicago, or the Smithsonian Natural History Museum, which have huge collections of specimens that are preserved for present and future scientists to study. The vast majority of what a museum holds is never put on exhibit. Museums are extremely important to preserve our biodiversity knowledge from around the world, and because a specimen exists, someone can always go back and check a scientific claim someone makes about a specimen (as long as the museum sticks around and maintains its collections and specimens). When someone describes a new species, they usually store their specimens in a museum so that they can be preserved in perpetuity.

1924! Just seeing specimens this old is truly valuable,
but identifying a species new to science is cooler!
Of course, I chimed in to the discussion. I got into the fish business to do taxonomy, but alas I don't have funds to go to far-off locales to find new species. Luckily, at the Auburn University Museum of Natural History, there's plenty to do, as my advisor and prior students have led multiple trips to South America to amass one of the largest collections for South American fishes in North America. I have also borrowed a number of specimens from other museums which also represent new species. I have not collected a single one of the species I'm describing, and I hope to describe several before my PhD is done. In fact, I recently submitted a manuscript for two new species of fish, one of which was first collected in 1924, and to my knowledge has not been collected since. Truly a forgotten new species.

And I wasn't alone. Numerous people responded who had described new species. Although many of these were people that specialized in South American fishes, there were other examples as well, from Africa, from Asia, as well as marine fishes, including deep sea fishes. There are so many species left to describe the specialists don't have enough time to describe them. As one member pointed out, there was a recent study where the "shelf life" of new species was calculated, or how long that species had been in a collection before it was formally described. On average, it was calculated a species goes about 21 years before being described. The authors of the study also point out that the vast majority of species are not even recognized as new in the field, and thus collections are important holding tanks for potential new species. Another member pointed out that one of the mother of all shelf lives was publicized last year with the discovery of a new species of beetle collected by Darwin himself, boasting a 180-year gap between collection and description.

A new species I am describing I found on the shelf, labeled as
unidentified with the telltale "sp." for its species.
For some of these specimens that remain to be described in collections, we already know they're there. Any specimens that are unidentified in a collection typically is a big clue. If a specialist wasn't able to identify some specimens to species, it could mean that they don't have expertise with that particular group... But it could also mean that the specimen can't be identified to a currently described species because it is new to science! On the other hand, we might not know that the specimens are a new species until further study. In some cases, new species have been hiding under our noses, under the guise of other already named species they are similar to. This is an increasingly common phenomenon, and species that have been hiding from us have been called "cryptic species." By keeping these specimens around, we can always go back and check if something was hiding from us all along.

It's clear, though, that discovery and description are too different things. Although I'm describing several new species of fish, can I really claim discovery? These fish were found by someone else first, so perhaps I can't claim that? It's because of this disconnect between discovery and description that leads me to avoid using the word "discovery" for the fish I'm describing. All of the fish I'm describing were already clearly different to whoever first tried to identify them and label their jar, but they simply never went ahead and formally described the species. Perhaps one day I'll truly discover a new species. But until then, hopefully I can at least continue describing them!

Thanks to everyone who contributed to the discussion: Rachel Arnold, Ricardo Benine, Andy Bentley, Mike Burns, Barbara Cálegari, Fabio Di Dario, David Ebert, Ben Frable, Les Kaufman, Flávio Lima, Hernan Lopez-Fernandez, Nathan Lujan, Daniel Lumbantobing, Marcelo Melo, Michael Mincarone, Javier Alejandro Maldonado Ocampo, Michael Oliver, Frank Pezold, C. Keith Ray, Luiz Rocha, Norma Salcedo, Scott Van Sant, Vivianne Sant'Anna, David Shiffman, Brian Sidlauskas, Randal Singer, Luke Tornabene, and Richard Vari.

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