Discovery helps researchers better understand so-called ‘cryptic’ species
Three new species of black-bellied salamanders have been discovered by a research team led by R. Alexander Pyron, Robert F. Griggs Associate Professor of Biology at George Washington University. The new salamanders, which are found in the southern Appalachians of the eastern United States, come from black-bellied populations that have long been considered a single species.
The finding sheds light on “cryptic” species, which are described as those with no obvious differences separating evolutionarily distinct populations. According to the researchers, the black-bellied salamanders were known as a single species for more than 100 years, but nevertheless have subtle differences between them.
“Black-bellied salamanders have been commonly studied for over 100 years,” Pyron said. “In 2002, a cryptic dwarf species was discovered, and in 2005 DNA evidence began to suggest there were even more. It was only through our 2020 NSF-funded research that we have able to sequence genome-wide data there were actually five similar-looking species.”
The researchers began by observing Desmognathus quadramaculatus, a poorly characterized species of salamander throughout its history. They noticed that certain morphological, genetic and geographical aspects differed between the specimens, including variations in size, shape and color. After sequencing the genome of D. quadramaculatus, researchers discovered five distinct species, three of which are new to researchers. The new species are now known as D. gvnigeusgwotli, D. kanawha and D. mavrokoilius.
“After examining several specimens, we see clear and substantial phenotypic variation between most lines,” Pyron said. “In fact, the name ‘quadramaculatus’, which has been used for over 120 years, is not the correct name for any of these five species. We have found the original specimens in museums in Philadelphia and Paris and have discovered that they belonged to a distinct species.This raises the question of how “cryptic” they are in the end.
According to the researchers, future studies should offer substantial additional information on the evolutionary history, geographic distribution, ecological interactions and other aspects of new black-bellied salamanders.
The National Science Foundation (DEB-1655737, DEB-0808451, DEB-1656111) supported this research.