Heather Shumway, Southern Utah University
Biology
Glossiphoniids are jawless leeches that feed using a proboscis, which they use to impale prey so that they can feed on their prey’s blood and tissues. This study focuses on two different species, Glossiphonia complanata and Helobdella stagnalis. Helobdella stagnalis feed on a variety of prey, including bloodworms and freshwater snails, often feeding together in large groups. When a prey item is placed in the container, H. stagnalis immediately begin smelling the water and moving toward the prey. After the first H. stagnalis makes contact and secures prey, other individuals within the group will move to that area, often passing prey along the way, to attach to the same prey item. Once a number of individuals have started feeding, the prey is often broken into smaller pieces and individuals can then begin feeding on various sized pieces. This is in contrast to members of the species Glossiphonia complanata, who appear to be selective with their prey, and have been observed going up to 4 weeks without feeding, even in the presence of their non-preferred prey (bloodworms). When preferred prey (freshwater snails) were placed in the container, unfed G. complanata did not immediately begin smelling the water or initiate hunting. Unlike H. stagnalis which feed in groups, G. complanata appear to prefer feeding alone, and have even exhibited competitive behaviors.