What has two short, chunky arms, a mane of feathery gills, and a sleek, green-marbled, eel-like body as long as your leg? No guesses? Meet the reticulated siren, a massive, two and a half foot-long salamander, described for the first time in a paper published today in the journal PLOS ONE, hailing from the remote, secluded wilds of *checks notes* southern Alabama and the Florida Panhandle.
Sirens are a small family of unusual salamanders found throughout the Southeastern U.S. and parts of Mexico. They are entirely aquatic, living in swamps and ponds and keeping their bushy external gills through adulthood. Ranging from a few inches to over three feet long, sirens have shrimpy forelimbs, and have ditched their hindlimbs altogether, leaving only a long, eel-like body and tail fin. Their name comes from their mermaid-adjacent body plan and their occasional “singing” and croaking.
Knowledge of the reticulated siren didn’t just spring into being overnight. For decades, the salamander had an almost mythical status in herpetology circles.
Sean Graham, a biologist at Sul Ross State University, author of American Snakes, and lead author on the new study, first heard about the enigmatic “leopard eel” in the early 2000s. “It was almost a rumored thing, almost like a unicorn,” he recounted. “Some biologists were familiar with it and had seen it.”
Hearing those biologists’ stories and seeing the handful of preserved specimens that were collected years ago left an impression. “I thought ‘holy crap, this is a big siren species that’s really obviously different,’ boldly colored and crazy looking!” Graham said. About ten years ago, while in graduate school at Auburn University, he mentioned the siren’s possible existence to then-fellow student David Steen, now a research ecologist at the Georgia Sea Turtle Center and coauthor on the study.
“We wanted to describe this mysterious siren that others had noted as occurring in southern Alabama,” Steen said. “But we had no real claim to the project; we knew that if we wanted to work on this species we had to find one in the wild ourselves.”
Graham and Steen periodically visited the salamander’s purported turf, but came back empty handed every time. Then, in 2009, Steen captured one in the Florida Panhandle.
A reticulated siren from northwestern Florida (Okaloosa County) (Photo: Pierson Hill)
“He just called me out of the blue, left a message on my phone like ‘I got one,’” Graham said. “I knew exactly what he meant, and drove down there right away.”
The captured salamander was visually striking, with skin dappled with reticulations instead of the standard dull, dark shade. Though, to be sure the siren was something unique, Graham and Steen would need more specimens.
Five years later, after much searching in the region, the researchers caught three more sirens in a Florida pond. Armed with these specimens, along with three others that were caught in Alabama in the 70s and preserved in a museum collection, the team compared the unusual sirens’ physical features, and DNA with other species.
It soon became clear that the salamander was a distinct, new species, dubbed Siren reticulata. Beyond its reticulated skin, the species has a smaller head than its relatives, and many more rib-hugging “costal grooves” along its sides.
At the risk of stating the obvious, a new, large vertebrate living right under our noses in the U.S. isn’t something that happens much anymore.
“This is a big animal,” Graham said, noting its status as one of the largest salamanders alive. “It’s got to be one of the largest species discovered in North America in probably 100 years.”
While the discovery of such a large animal so recently may be surprising, the fact that it happened in Alabama and the Florida Panhandle specifically is less so. The region is a hotspot of endemics, with many other species found there and nowhere else, according to Alexa Warwick, an amphibian evolutionary biologist at Michigan State University who wasn’t involved with the new study.
“The geology of the area has really driven the a lot of the diversity in the types of habitats that are available, and in turn, the kinds of species we find all across the region,” Warwick explained. The place is a mosaic of seepage and pitcher plant bogs, steephead valleys, pine woodlands, and springs, creating a unique evolutionary laboratory.
But if, like the Florida bog frog, the reticulated siren is only found in a few specific places on the Panhandle, that could put the species at risk going forward, Graham said. While there are accounts of hundreds of sirens spotted in single spots, there are currently no formal estimates of the species’ population size or distribution, and they could still be vulnerable.
“If they’re locally abundant in six known ponds, and a hurricane comes through and a big storm surge dumps saltwater it could wipe out half their ponds,” Graham said.
Now that the reticulated siren has been introduced to the world, the crucial work of figuring out its most basic natural history begins. “Formally describing a species is an essential first step towards conservation,” said Amber Pitt, a conservation ecologist at Trinity College who also wasn’t involved with the new study. “But now we need basic information about its distribution, population status, and ecology.”
The new species is thought to eat what all sirens eat (aquatic insects and mollusks), and live in the same muck-bottomed ponds and waterways where all sirens live. But more details about its habitat and range will need to come with additional surveys.
A reticulated siren from northwestern Florida (Okaloosa County) (Photo: David Steen)
For now, the reticulated siren’s existence shines a light on North America’s underappreciated biodiversity. The Alabama River drainage, for its size, has the highest diversity of turtles of anywhere in the world. North America overall is #1 in the world for salamanders – which Graham describes as our “finest vertebrates” – with several whole families (including sirens) found nowhere else on Earth.
“I consider salamanders our greatest vertebrate export to the rest of the world,” says Graham. “Salamanders arose here, and they’re awesome. People should know about that, and be proud of it.”
Featured image: Pierson Hill