Leeches can track jungle mammals

Monitoring the abundance of mammalian species in tropical rain forests is difficult due to the uncooperative environment. Not only does the thick canopy of leaves above shield the forest floor from the sun, but the moist ground and thick vegetation means researchers have difficulty in moving through the undergrowth and additionally, many tropical mammals retain a nocturnal lifestyle.

Leeches can 'store' mammalian DNA

Now a team of researchers from Copenhagen and Cambridge publishing in Current Biology has shown that mammalian blood can be identified from within leeches for at least four months following feeding. The scientists then investigated 25 specimens of the Haemadipsa leech from the Central Annamite rain forest in Vietnam from which they were able to identify mitochondrial DNA specific to 6 mammal species, including that from Capricornis maritimus, a goat-antelope threatened by environmental degradation from logging. Other mitochondrial DNA recovered serves as the first confirmed record of the Annamite striped rabbit (Nesolagus timminsi) being present in the area sampled.

Other species of leech are used in biomedicine research due to the naturally occurring anticoagulant they produce. Now the scientists hope this tropical species and others like it will help conservation biologists monitor biodiversity inexpensively and more easily in hard to reach tropical environments.

Written by Nick Crumpton

DOI: 10.1016/j.cub.2012.02.058