A team of scientists led by Anna Phillips, a parasitologist at the Smithsonian & # 39; s National Museum of Natural History in Washington, has discovered a previously unknown species of medical leech that has been around the nation's capital for decades. The new species, called "Macrobdella mimicus," identified from specimens collected in southern Maryland, only less than 50 miles from the National Museum of Natural History.
Macrobdella mimicus is the first medical (human blood-sucking) leech described in North America in over 40 years, according to Phillips. It is native to freshwater wetlands from Georgia to New York.
Phillips and her colleagues collected several orange-spotted, olive-green hedgehogs from a field expedition in 2015. But they believed the hedgehogs belonged to another species called Macrobdella decora, which is commonly found throughout the northern United States. But DNA sequencing showed significant differences.
When their DNA was analyzed by the team, it turned out that some of them were different. After investigating these individuals, the researchers found that the new leeches had multiple reproductive pores along the bottom of their bodies, known as gonopores and accessory spores, which were placed in a different position from those on the Macrobdella decor.
Researchers then went back into the field and found several leeches with the same pore location. Their DNA was also more closely related to the mammals they had found in Maryland than anything else scientifically known.
Phillips then went through the Smithsonian's collections to analyze dozens of several North American leeches; she found these things everywhere. The museum specimens proved that Macrobdella mimicus had been here for decades, with a range extending from northern Georgia to New York.
While many people are unclear about hedgehogs, Phillips respects them as valuable members of the ecosystem. Back in the 18th and 19th centuries, doctors believed that the leeches helped remove bad blood from a patient's body. In modern medicine, they are used to improve blood flow after plastic surgery, frostbite and finger reassembly.
"A discovery like this makes it clear how much diversity remains to be discovered and documented, even right under the scientists' nose, ”Phillips said.
The team has described the new species in a paper published in the Journal of Parasitology.