title: Infection with schistosome parasites in snails leads to increased predation by prawns: implications for human schistosomiasis control.
abstract: Schistosomiasis - a parasitic disease that affects over 200 million people across the globe - is primarily transmitted between human definitive hosts and snail intermediate hosts. To reduce schistosomiasis transmission, some have advocated disrupting the schistosome life cycle through biological control of snails, achieved by boosting the abundance of snails' natural predators. But little is known about the effect of parasitic infection on predator-prey interactions, especially in the case of schistosomiasis. Here, we present the results of laboratory experiments performed on Bulinus truncatus and Biomphalaria glabrata snails to investigate: (i) rates of predation on schistosome-infected versus uninfected snails by a sympatric native river prawn, Macrobrachium vollenhovenii, and (ii) differences in snail behavior (including movement, refuge-seeking and anti-predator behavior) between infected and uninfected snails. In predation trials, prawns showed a preference for consuming snails infected with schistosome larvae. In behavioral trials, infected snails moved less quickly and less often than uninfected snails, and were less likely to avoid predation by exiting the water or hiding under substrate. Although the mechanism by which the parasite alters snail behavior remains unknown, these results provide insight into the effects of parasitic infection on predator-prey dynamics and suggest that boosting natural rates of predation on snails may be a useful strategy for reducing transmission in schistosomiasis hotspots.
authors.affiliation: Department of Biology, Stanford University, Stanford, CA 94305, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Swartz
authors.affiliation: Department of Biology, Stanford University, Stanford, CA 94305, USA Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA.
authors.forename: Giulio A
authors.initials: GA
authors.lastname: De Leo
authors.affiliation: Department of Ecology and Evolutionary Biology, University of Michigan, Ann Arbor, MI 48109, USA Michigan Society of Fellows, University of Michigan, Ann Arbor, MI 48109, USA.
authors.forename: Chelsea L
authors.initials: CL
authors.lastname: Wood
authors.affiliation: Hopkins Marine Station of Stanford University, Pacific Grove, CA 93950, USA Marine Science Institute, University of California, Santa Barbara, CA 93106, USA shsokolow@gmail.com.
authors.forename: Susanne H
authors.initials: SH
authors.lastname: Sokolow
mesh_terms: D000818:Animals; D061046:Biological Control Agents; D001700:Biomphalaria / Q000469:parasitology*; D002033:Bulinus / Q000469:parasitology*; D006801:Humans; D007814:Larva; D033541:Palaemonidae / Q000502:physiology*; D011235:Predatory Behavior; D012548:Schistosoma haematobium / Q000502:physiology*; D012550:Schistosoma mansoni / Q000502:physiology*; D012552:Schistosomiasis / Q000517:prevention & control / Q000635:transmission
chemical_list: D061046:Biological Control Agents
keywords: Behavior manipulation; Biological control; Parasitism; Schistosoma