Tuesday, February 17, 2015

New paper on 3 new species of Peckoltia!

Three new species of armored suckermouth catfish (family Loricariidae), also known as plecos, have been recently described by my advisor Jon Armbruster, David Werneke, and myself! We also reclassified many of the related species, which is based on findings from a recent study of the evolutionary relationships of loricariid catfish that Jon worked on with a number of colleagues. As the paper is open access, I invite you to check it out at ZooKeys.

Peckoltia greedoi (Photo credit Jon Armbruster)
The three new species are of the genus Peckoltia. They are fairly similar, but come from different parts of South America. The number of rivers in the South American rainforest has helped promote isolation and diversification for many groups, including these catfish. In fact, many loricariids are popular in the pet trade. While many people are familiar with common plecos, often used to clean up algae, there are many more species. Aquarists are so into plecos that they import many species before they've even been described, and undescribed species are given an L-number designation by aquarists as a placeholder name until it gets described.

In describing the new species, our colleague, arachnologist Chris Hamilton, remarked that one of the fish looked like Greedo, the bounty hunter from Star Wars: A New Hope. We knew immediately we would have to name the new species Peckoltia greedoi. Peckoltia greedoi comes from the Gurupi River drainage in Brazil. We've gotten some attention for this, and we have been featured as a Name of the Week on EtyFish (a website that maintains a list of fish name etymologies). We also got an article in Auburn's The War Eagle Reader. Plus, we had great response from sci-fi fans, with articles written about our paper on Nerdist, which then spread to a bunch of other sci-fi websites. Peckoltia greedoi also inspired a listing of Star Wars-inspired species! Particularly relevant to our new species, there is a trilobite called Han solo. I suppose it's a good thing species have never crossed paths. Scientists are a nerdy bunch, and it's clear scientists aren't above having fun with naming things.

UPDATE 3/19/2015: It turns out the Greedo catfish had some life in it yet for getting people's attention. About a month and a half after the paper first hit, Auburn University wrote a story on our new species and included a video! This subsequently spread to many news sources including CNN, BBC, The Telegraph, IFLScience, Washington Post, and even IGN! Really exciting to have so much attention, just in time for Taxonomist Appreciation Day!

Peckoltia lujani (Photo credit: Jon Armbruster)
As far as I know, only one of the three species we have described has shown up in the pet trade and gotten an L-number. Peckoltia lujani is, to the best of my knowledge, the species known as L127 in the pet trade. My advisor has described quite a few species from the Orinoco River, and this one adds another species to the count. Peckoltia lujani was named for one of Jon's previous graduate students, Nathan Lujan, who has become a loricariid expert in his own right. Although P. lujani is overlooked by many aquarists since it has a relatively drab color pattern, it is still kept by quite a number of aquarists. Devoted hobbyist aquarists interested in loricariid catfishes watch the scientific literature closely (I myself got into science because of this), and they were excited to have a name to another species that they keep.

We also named a third new species, Peckoltia ephippiata. The name refers to the dark "saddle" color pattern formed by blotches on its back. Peckoltia ephippiata occurs in the Madeira River.

Loricariid specialists and pleco aficionados alike may also be interested in some of the reclassifications that were made. Unfortunately, Peckoltia is a poorly understood genus, as is a closely-related genus Hemiancistrus. These two genera have been thought to be very similar, but Hemiancistrus species could be distinguished from Peckoltia by the angle at which their lower jaws come together, which either form a wide angle in Hemiancistrus or an acute angle in Peckoltia. In an earlier study, using analyses of DNA sequences from hundreds of species, Jon Armbruster and colleagues helped to clear up the relationships. It turns out that jaw angle didn't work very well for determining evolutionary relationships, and so Peckoltia and Hemiancistrus as previously defined were not evolutionarily meaningful (which is a goal of classification). The three new species group with Peckoltia in the molecular phylogeny, but have jaw angles about 90º, so they don't qualify under the traditional definition of Peckoltia; however, since they do group together evolutionarily, we decided to classify them under the genus Peckoltia. The DNA study also found Hemiancistrus included species that are different genera; we resurrected a previously named genus, Ancistomus, to include some of these species, but some of the rest will remain until new genera are named. Peckoltichthys was resurrected for the unusual P. bachi, which was grouped in Peckoltia for a while. Also, the unusual Hemiancistrus pankimpuju was moved to Peckoltia based on its evolutionary relationships.

There's still a lot to find out about these catfish. Unfortunately, right now we don't know what Peckoltia specifically is. Although the species in Peckoltia conforms to our knowledge of the evolutionary relationships of these fish, we don't yet know if there's a specific morphological character that unites the genus as we've currently grouped it. It's a small distinction that is dissatisfying for taxonomy, as being able to identify genera by morphological characters is important when you don't have genetic techniques at hand. However, for now, we leave the taxonomy in an interim state that represents our knowledge of the evolutionary relationships of these fish from genetic sequence data. Hopefully in the future these relationships can be clarified, and we can solidly diagnose these genera.

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.