Potential New Dusky Species in Virginia

2/21/2022

Adult "Fuscus B2" - © Ty Smith

Duskies (Desmognathus) have always been a confusing genus of salamanders. Most people struggle with the physical differences of these salamanders, but others like myself have noted some slight and some vast differences in their appearance among different populations. For example, I have long speculated that “Northern Duskies” (D. fuscus) in the Piedmont look more like, and may be, Flathead Salamanders (D. planiceps). Well, I was right in my observation but wrong in my conclusion. We have said that someone would have to DNA sample these Duskies to give us a full picture of what is really going on. Finally, Robert Alexander Pryon et al. have explored these species and came up with some interesting results. A few days ago, a massive new paper was published by them. This paper, “Candidate-species delimitation in Desmognathus salamanders reveals gene flow across lineage boundaries, confounding phylogenetic estimation and clarifying hybrid zones”, has loads of new genetic information. For example, the 22 species in this genus found in the eastern United States may grow to contain up to 47 species! What does this mean for Dusky species in Virginia? Well, here is a list of possible new species that may arise.

Basically, the geographical variation we have noticed is probably due to these one of two things: 1. These populations are new species, or 2. These populations are intergrades. This is confusing as several of these new species are the result of species diverging, intergrading, and then evolving in a different direction from their ancestors. A good example seems to be the Dusky referred to as “fuscus C1”. This salamander seems to be the result of the Holbrook’s Southern Dusky (D. auriculatus) and Northern Dusky intergrading back together, to create a new lineage that has evolved into a new species. Remember when I mentioned our Southern Piedmont specimens appear more like Flathead Salamanders? That is because they are actually fuscus C1. So we were right in saying they were very different in appearance with their more broken dorsal pattern and portholes on their tail but wrong in our interpretation that these were possibly Flathead Salamanders. This is one of several new species and name changes that could be coming.

So, let’s dive into the potential new species that might be found in Virginia. I know it's difficult to associate a letter/number to a name, so I will give a place-holder nickname for now, as it will probably be months or years before these get true names.

Upland Dusky Clade

Fuscus B2: "Northern Dusky"

Adult - © Ty Smith

I presume that this will remain the Northern Dusky, as it seems to be the population under which this species, Desmognathus fuscus, was described. These seem to be the textbook Northern Duskies with no portholes on the tail. That said, fuscus B1 could retain the common name, and if so, I would suggest fuscus B2 should be called the “Virginia Dusky”.

Fuscus A: "Kentucky Dusky"

Adult - © Ty Smith

This salamander is found across Tennessee and Kentucky, but slips into Lee and Scott Counties, and probably northern counties in that area like Dickinson as well. I have only seen this potential new species a few times, but they seem fairly dark with a tan back.

Fuscus E: "Yadkin Dusky"

Adult - © Ty Smith

Juvenile - © Ty Smith

This salamander is only found in the northern Yadkin River watershed, and barely into Carrol Co. They are quite similar to Flathead Salamanders, but often seem to possess darker reds on the dorsal as juveniles. We have always just thought of these as a separate population of the Flathead Salamanders, but I am excited about the prospects of this becoming a species.

Lowland Dusky Clade

Fuscus C1: "Southside Dusky"

Adult - © Ty Smith

Juvenile - © Ty Smith

In the midst of all this new data, you have this weird anomaly. Fuscus C is called so, as its mitochondrial DNA is closest to the Northern Dusky. That said, its nuclear DNA is most similar to the Holbrook's Southern Dusky, which is what a portion of the population was considered until now. The Lowland Dusky Clade are extensions off of that hybrid lineage I mentioned above. Fuscus C1 seem to be the Duskies south of the James, and the go slightly below the NC line, with the exception of areas around Mecklenburg, where Fuscus D can be found. They range south, down the east coast of NC as well. I am personally surprised that the animals in Halifax and Sussex Counties are both considered this species and not two separate groups. Time will only tell the future of these Duskies, but Pryon has said that this is by far the most variable group of Duskies he tested.

Fuscus D: "Piedmont Dusky"

Adult - © Ty Smith

This is the predominant species in central North Carolina, but is found in at least Mecklenburg County. These are also unique in appearance, some looking black, and have clear portholes on the tail. This species is also most similar to the Holbrook's Southern Dusky geneticly.

Other Duskies

Monticola A/C: Seal Salamander

Juvenile - © Ty Smith

This species will probably end up splitting from Monticola B, but our local Seal Salamander (Monticola A/C) will likely keep its name. If the common name does change, I would guess it would be the “Northern Seal Salamander”. Monticola B often tends to be greener with redder patterns, while our local Seal Salamander (Monticola A/C) is usually olive-gray to brown with yellow or orange patterns.

Marmoratus E/H: Shovelnose Salamander

Adult - © Ty Smith

I really do not know if these split, which one will likely keep the name. I would guess if they split, we would see the "Northern Shovelnose Salamander" (Marmoratus E/H) and "Southern Shovelnose Salamander" (Marmoratus C).

Quadramaculatus D: "Northern Black-bellied Salamander"

Interestingly enough, per Pryon himself, the name "Quadramaculatus" is going away. I look for the common name to repersent this being the northern-most species in the complex. This is mainly due to the Dwarf Black-bellied Salamander that already is named, and the potential addition of Quadramaculatus C and Quadramaculatus G.

UPDATE!

Quadramaculatus D has been described now as the Kanawha Blackbelly Salamander (D. kanawha). This, in my opinion, is a much better name than just "Northern" as my initial thought was. I also like "Blackbelly" more than the overly prim and proper "Black-bellied". The other new species are the Blue Ridge Blackbelly Salamander (D. mavrokoilius), Cherokee Blackbelly Salamander (D. gvnigeusgwotli), and the Southern Blackbelly Salamander (D. amphileucus). I personally love these names as they have good diversity, and are not all named after rivers, cardinal directions, or mountain ranges. To me, names like "Northern" can be good names to describe a species, but when all of the names are cardinal directions, it doesn't look like much thought went into the names. It also can be confusing, as with Two-lined Salamandes, if the lines are not exactly perfect, and some times how far east and west you are can be more important as your position north and south. I am particularly happy this isn't just the "Northern Black-bellied Salamander" because I am sure several of the new species to be named are candidates for this "Northern ____" treatment, such as the Seal Salamander and the Shovelnose. Nothing is worse than looking down an alphabetized list and trying to find a species like the "Northern Slimy" with twelve other "Northern ____" on the list.

Orestes C: "Mount Rogers Dusky"

This is one of those potential new species I expect to be in the split and not keep its name. I suspect Orestes A will keep the name “Blue Ridge Dusky” and Orestes C to take a new name like “Mount Rogers Dusky” or “Grayson Dusky”.

These are the splits that will affect our Virginia species. I am excited about the prospects of this paper, and encourage all to read it; I have linked it below. If you think I missed anything, email us to discuss these new potential changes.

Full Paper

Works Cited:

Pyron, R. A., O’Connell, K. A., Lemmon, E. M., Lemmon, A. R., & Beamer, D. A. (2022). Candidate‐species delimitation in Desmognathus salamanders reveals gene flow across lineage boundaries, confounding phylogenetic estimation and clarifying hybrid zones. Ecology and Evolution, 12(2). Wiley Online Library. https://doi.org/10.1002/ece3.8574