New Species Of Blood-Sucking Leech Discovered In DC-Area Swamps

WASHINGTON, DC — A Smithsonian researcher has just stumbled upon a major discovery in the swamps in and around D.C.: a new species of blood-sucking leeches with up to 59 teeth.

The Smithsonian Magazine reports that Smithsonian research zoologist Anna Phillips and other scientists began collecting local leeches in the summer of 2015, but they had no idea they were part of a new species. Now, Phillips and her colleagues have published a paper in the Journal of Parasitology describing Macrobdella mimicus, the first new leech species discovered on the continent in four decades. Previously, such leeches would have been mistaken for Macrobdella decora, a common species which lives in slow-moving freshwater and feeds on fish, amphibians, and some mammals.

Phillips, who serves as a curator of parasitic worms and invertebrate zoology at the National Museum of Natural History, explored streams and ponds across the eastern United States, checking under rocks and even letting leeches latch on to her legs.

Macrobdella mimicus is the first N. American medicinal leech species discovered in 40 years! #NBD. The orange-spotted, olive-green leech, was found on a field expedition in a Maryland swamp, but the species ranges across the Piedmont region of the eastern U.S. pic.twitter.com/luD0dslKuF
— Smithsonian's NMNH (@NMNH) August 15, 2019

They were shocked after DNA tests indicated that some of the leeches had genetic fingerprints that were as much as 6-11 percent different from the others -- genetic differences of just two percent typically indicate the specimens are different species, according to Smithsonian Magazine.

The leech is an olive-geen color and is about as long as a cigarette. They have three jaws, which each contain 56-59 teeth used for biting and then draining blood from their victims.

After further research, Phillips believes that the leech's range goes from Northern Virginia up to Long Island.