By Stephen Beech via SWNS
Leeches really can JUMP, reveals new research.
Scientists recorded the first conclusive video evidence, in Madagascar, of a terrestrial bloodsucker jumping from a leaf, rebutting previous doubts that they could do so.
Researchers had debated for more than a century whether leeches could jump until the ground-breaking footage, published in the journal Biotropica.
Scientists from the American Museum of Natural History, Fordham University, and City University of New York (CUNY)’s Medgar Evers College recorded the footage during two field trips to the island off East Africa.
Lead author Dr. Mai Fahmy, of Fordham University, New York, said: “We believe this is the first convincing evidence that leeches can jump and do so with visible energy expenditure.
“There have been previous accounts of leeches jumping, including onto people, but those reports were often explained away as leeches just attaching to passers-by as they brushed against shrubs or dropping from a branch above.
“This study dispels that argument.”
Dr. Fahmy recorded footage of leeches from the genus Chtonobdella coiling back on a leaf and then taking off. during two separate expeditions to Madagascar in 2017 and in 2023.
Dr. Fahmy and co-author Dr. Michael Tessler, an Assistant Professor at CUNY’s Medgar Evans College, compared the motion to a “back-bending cobra” or to a spring being pulled back.
In both cases, the leech keeps its body extended as it soars through the air to the ground, in a notable departure from their usual inchworm-like movements.
Dr. Tessler said: “Essentially, it executes a graceful jump but with a seemingly hard landing.”
The researchers said several other worm-like invertebrates can jump, including the legless larvae of gall midges, which assume a loop posture before propelling themselves into the air, the larvae of Mediterranean fruit flies and several caterpillars.
Dr. Fahmy collected the jumping leech she observed on the 2023 trip, and the researchers identified it as Chtonobdella fallax, a common species in Madagascar.
The larger Chtonobdella group of leeches to which C. fallax belongs can be found across Madagascar, the Seychelles, the Malay Archipelago, and the South Pacific Islands.
Dr. Tessler said: “We do not know how often this may happen or whether these leeches use this ability to seek out hosts, but, given that we caught multiple jumps in two short recordings, this behaviour may be common for this species.”
The researchers stressed that understanding overall leech behaviour is also important to conservation efforts because leeches – and more specifically, their blood meals – are increasingly being collected to survey vertebrate biodiversity.
Dr. Fahmy added: “If we can identify how leeches find and attach to hosts, we can better understand the results of their gut content analyses.
“Leeches are also often overlooked and understudied, and, as a natural part of the ecosystem, leeches themselves may be in need of conservation protection.”
