Scientific News

New species of medicinal leech identified in the USA

A new species of medicinal leech has been discovered in freshwater wetlands in southern Maryland. Called Macrobdella mimicus, the new leech has been classified by an international team of museum scientists led by Anna Phillips, one of the curators of the US National Museum of Natural History.

Phillips herself explains the discovery as follows: “We found a new species of medicinal leech less than 50 miles from the National Museum of Natural History – one of the world’s largest biodiversity libraries. A discovery like this clarifies how much diversity is still to be discovered and documented, even right under the nose of scientists.”

The leeches are parasitic worms that until 1800 were used in medicine to treat various ailments because it was believed, a belief later revealed to be wrong, that it could eliminate the infected or in any case bad blood from the patient’s body. The so-called “medicinal leech” is that which is able to feed even with human blood.

The researcher had collected this specimen of leech from a Maryland swamp. After Ricardo Salas-Montiel, a student at the National Autonomous University of Mexico, carried out DNA sequencing, the researchers realized that it did not belong to known species, in particular it did not belong to the Macrobdella decorates species, as the researchers themselves thought when they had discovered it.

In addition to genetic differences, there is a visible physical difference between the two species: the new one, the mimicus, boasts reproductive pores along the body (organs also known as gonopores) in a different position.