|Peckoltia greedoi (Photo credit Jon Armbruster)|
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.
|Peckoltia lujani (Photo credit: Jon Armbruster)|
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.