Atiny creature living in the Great Salt Lake has turned out to be a species never seen before. Named Diplolaimelloides woaabi, the microscopic animal appears to exist nowhere else on Earth and is giving researchers a rare glimpse into life in one of North America’s harshest environments.
The discovery was made by scientists from the University of Utah, who spent several years studying the worm before confirming it was a new species. Measuring less than 1.5 millimeters long, it was found living inside microbialites, rocky structures created by communities of microorganisms on the lake floor.
The finding adds a surprising new resident to the Great Salt Lake. Until now, the lake’s salty waters were mainly known for supporting brine shrimp and brine flies.
A Tiny Creatures Hiding In Plain Sight
The worm was first spottedin 2022 by researcher Julie Jung while collecting samples from the Great Salt Lake. At the time, she was working as a postdoctoral researcher in the laboratory of biologist Michael Wernerat the University of Utah.
Nematodes are incredibly common animals. These creatures can be found almost everywhere, from garden soil and freshwater ponds to polar regions and deep-ocean environments. More than250,000 species have been described worldwide. Yet none had previously been confirmed in the Great Salt Lake.
According to the study published in the Journal of Nematology, researchers suspected early on that they had found something unusual. Confirming that suspicion took much longer. The team relied on DNA sequencing as well as high-resolution microscopy to compare the worms with known species.
The analyses revealed several distinctive features, including eyespots, fused lips, a funnel-shaped mouth cavity, short sensory bristles, and unique reproductive structures in males.
“We thought that this was probably a new species of nematode from the beginning, but it took three years of additional work to taxonomically confirm that suspicion,” Jung said.
The creatures was eventually named Diplolaimelloides woaabi. The name honors the Northwestern Band of the Shoshone Nation. Before choosing it,Michael Werner consulted tribal elders, who suggested the word “Wo’aabi,” meaning “worm.”
How Did It Get There?
One of the biggest questions surrounding the discovery is how a creature of this genus ended up in a landlocked lake in Utah. Most known species related to Diplolaimelloides woaabi are associated with coastal marine or brackish environments. The Great Salt Lake, by contrast, sits about 4,200 feet above sea level and roughly 800 miles from the nearest ocean.
As reported by the co-author Byron Adams, a biology professor at Brigham Young University, one possibility is that the worm’s ancestors have been in the region for an extraordinarily long time. He points to the ancient Western Interior Seaway, which covered parts of North America during the Cretaceous Period.
“With the Colorado Plateau lifting up, you formed a great basin, and these animals were trapped here. That’s something that we have to test out and do more science on, but that’s my go-to. The null hypothesis is that they’re here because they’ve always kind of been here,” Adams said.
If that idea proves correct, the species may have survived major environmental changes over millions of years, including the appearance of Lake Bonneville, the enormous freshwater lake that once covered much of northern Utah.
Researchers are also considering another explanation. Migratory birds could have transported the worms, or their eggs, from distant saline lakes. The Great Salt Lake is one of the most important bird stopovers in North America, making long-distance transport a possibility.
A Hidden Great Salt Lake Clue
The discovery is about more than adding a new species to the scientific record. Researchers believe the worm could help them better understand how the Great Salt Lake ecosystem functions.
The team found Diplolaimelloides woaabi living within microbialite-associated algal mats, where it appears to feed on bacteria. Most individuals were concentrated in the upper few centimeters of these mats rather than deeper inside them.
Scientists also uncovered an unexpected mystery involving the species’ sex ratio.
“That’s another confusing part of the story for us,” Werner said. “When we sample out there on the lake and bring them back in the lab, we get less than 1% males. But when we have cultured them in the lab, the males make up about 50% of the sex ratio.”
The researchers expalained that the nematodes are often used as bioindicators because they react quickly to changes in environmental conditions. That sensitivity could make Diplolaimelloides woaabi a useful species for tracking the health of the Great Salt Lake.
For now, scientists have confirmed that the creature survives in the extreme conditions of the america’s harshest lakes, and that it has not been identified anywhere else. Its origins, however, remain unknown.
