The University of California, Davis has recently discovered that the McCloud River Redband Trout, also known as O. mykiss calisulat, is a distinct subspecies of rainbow trout. This marks the first time a new subspecies of Pacific trout has been identified since 2008, and is the most recently identified subspecies of rainbow trout, with a gap of over a century since the discovery of the previous one.
Fish biologists have long suspected that the McCloud River Redband Trout was a distinct subspecies, but it was not until the use of more advanced genetics techniques, including genome-wide DNA sequencing, that the UC Davis-led team was able to confirm this suspicion and solve the puzzle, as stated in a corresponding study published in the journal Zootaxa.
The UC Davis-led team confirmed the trout as a subspecies using newer genetics techniques, including genome-wide DNA sequencing. This finding corresponds with a study published in the journal Zootaxa, which notes that fish biologists have long suspected that the trout was its own subspecies since the 1970s. However, it was only through the use of these advanced genetic techniques that the puzzle was finally solved.
The McCloud River in Northern California begins as a network of spring-fed streams near Mount Shasta and cascades down a series of waterfalls known as the McCloud Falls. These waterfalls serve as a barrier to fish trying to swim upstream, creating a division between the Upper McCloud River and the Lower McCloud River. The Upper McCloud Basin is home to the McCloud River Redband Trout, which is the only native fish species found in the area.
“It’s persisted so long in isolation,” said lead author Matthew “Mac” Campbell, a research affiliate with the Department of Animal Science’s Genomic Variation Laboratory. “They’ve survived in glacial refugia during the Pleistocene era and have been above those waterfalls for at least 10,000 years.”
When considering a name to use, Campbell said this fish was clearly in the range of one tribe, the Winnemem Wintu. “They already had a name for the fish—a few thousand years before I did,” Campbell said.
Campbell collaborated with the tribe to create a formal description of a subspecies for western science, which he named O. mykiss calisulat. In the Winnemem Wintu language, the McCloud River Redband Trout is called “cali sulat,” with “cali” meaning good or beautiful and “sulat” referring to trout. The scientific name combines these two words in accordance with established scientific naming conventions.
The current fisheries management policies already provide support to the O. mykiss calisulat populations, so renaming the species does not affect its protective status. However, the act of renaming acknowledges its inherent importance.
According to Amanda (“Mandi”) J. Finger, associate director of the Genomic Variation Laboratory at UC Davis, this fish holds significance in the history and heritage of California, which often goes unrecognized. It embodies the story of the state, the tribes, and the hatchery. Thus, naming the species is a deserved recognition.
The discovery of O. mykiss calisulat is just the latest in a series of recent findings that have revealed new species and genetic diversity within existing species. Scientists say that these discoveries underscore the importance of protecting biodiversity and preserving the natural world for future generations.
The team at The Fish’n Canada show would like to congratulate the researchers from UC Davis. Keep on Fish’n!
Source: UC Davis
