Molecular diet studies of water mites reveal prey biodiversity

RESEARCH ARTICLE Molecular diet studies of water mites reveal prey biodiversity Adrian A. VasquezID1,2*, Obadeh Mohiddin3, Zeyu Li3, Brittany L. Bonnici1,3, Katherine Gurdziel4, Jeffrey L. Ram3 1 Healthy Urban Waters, Department of Civil and Environmental Engineering, Wayne State University, Detroit, Michigan, United States of America, 2 Cooperative Institute for Great Lakes Research, School for Environment and Sustainability, University of Michigan, Ann Arbor, Michigan, United States of America, 3 Department of Physiology, Wayne State University School of Medicine, Detroit, Michigan, United States of America, 4 Genome Sciences Core, Wayne State University, Detroit, Michigan, United States of America * avasquez@wayne.edu Abstract Water mites are diverse aquatic invertebrates that provide potentially important ecosystem and economic services as bioindicators and mosquito biocontrol; however, little is known about water mite digestive physiology, including their diet in nature. Water mites, much like their spider relatives, liquefy their prey upon consumption. This results in the absence of morphologically identifiable prey in water mite mid-gut. Previous studies have reported associations in the field of water mites with presumed prey and laboratory observations of water mites feeding on specific organisms offered for ingestion; however, the present work aims to determine what water mites have ingested in nature based on molecular studies of gut contents from freshly collected organisms from the field. To elucidate water mite prey,

we used next-generation sequencing to detect diverse cytochrome oxidase I DNA barcode sequences of putative prey in the guts of 54 specimens comprising two species of Lebertia and a few specimens of Arrenurus (2) and Limnesia (1). To our knowledge this is the first molecular study of the diets of water mites as they feed in nature. While the presence of chi- ronomid DNA confirmed previous observations of midge larvae as part of the diets of Leber- tia, we also found the DNA of diverse organisms in all four species of water mites, including the DNA of mosquitoes in 6 specimens of Lebertia and a large number of previously unknown prey, especially from oligochaete worms. These studies thereby reveal a greater diversity of prey and a potentially broader significance than previously appreciated for water mites in aquatic food webs. Molecular studies like this can detect water mite predators of mosquito larvae and add knowledge of water mite predatory contributions to freshwater food webs. Introduction Water mites are small carnivorous arachnids that are fully adapted as adults to water. They have a complex life cycle in which the larvae of most water mite species parasitize adult aquatic PLOS ONE PLOS ONE | https://doi.org/10.1371/journal.pone.0254598 July 29, 2021 1 / 18 a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 OPEN ACCESS Citation: Vasquez AA, Mohiddin O, Li Z, Bonnici BL, Gurdziel K, Ram JL (2021) Molecular diet studies of water mites reveal prey biodiversity. PLoS ONE 16(7): e0254598. https://doi.org/ 10.1371/journal.pone.0254598

Editor: Livia Maria Silva Ataide, Universidade Federal de Lavras, BRAZIL Received: January 29, 2021 Accepted: June 29, 2021 Published: July 29, 2021 Copyright: © 2021 Vasquez et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: All relevant data have been uploaded to a public repository and are available at: https://digitalcommons.wayne.edu/ physio_frp/2/. Funding: National Institute of General Medical Sciences NIGMS-R25GM-058905 Dr. Adrian Amelio Vasquez National Institutes of Health RL5GM118981, TL4GM118983, and 1UL1GM118982 Dr. Adrian Amelio Vasquez Sharon L. Ram Aquatic Sciences Fund, administered by the Community Foundation of Southeast Michigan Dr. Adrian Amelio Vasquez