Terrestrial Leeches, iDNA Surveys, and Beyond

Terrestrial leeches have long been famous for their blood-feeding behavior, feeding on humans who venture into wet forests across much of the Indo-Pacific. More recently these leeches have emerged as a tool for detecting vertebrate diversity in conservation studies. Specifically, scientists use DNA from the bloodmeals found in these leeches' digestive tracts to identify mammals, reptiles, amphibians, and birds they have fed on. Although this so-called invertebrate-derived DNA (iDNA) technique has grown in popularity, few resources exist for researchers to gain familiarity with these methods. Most researchers using these methods have a vertebrate conservation focus and therefore may benefit from learning more about the leeches, which are variable and also potentially in need of conservation. For this review, we focused on providing basic information on iDNA best practices and precautions, and on Haemadipsidae leech background and taxonomy. We hope this information empowers more people who live and study in the Indo-Pacific to work with these blood-feeding worms.