title: Parasite-induced changes in nitrogen isotope signatures of host tissues.
abstract: To estimate isotopic changes caused by trematode parasites within a host, we investigated changes in the carbon and nitrogen isotope ratios of the freshwater snail Lymnaea stagnalis infected by trematode larvae. We measured carbon and nitrogen stable isotopes within the foot, gonad, and hepatopancreas of both infected and uninfected snails. There was no significant difference in the delta13C and delta15N values of foot and gonad between infected and uninfected snails; thus, trematode parasite infections may not cause changes in snail diets. However, in the hepatopancreas, delta15N values were significantly higher in infected than in uninfected snails. The 15N enrichment in the hepatopancreas of infected snails is caused by the higher 15N ratio in parasite tissues. Using an isotope-mixing model, we roughly estimated that the parasites in the hepatopancreas represented from 0.8 to 3.4% of the total snail biomass, including the shell.
authors: Graduate School of Life Sciences, Tohoku University, 2-1-1, Katahira, Aoba-ku, Sendai 980-8577, Japan. hdoi@u.washington.edu
authors: Hideyuki
authors: H
authors: Doi
authors: Natalia I
authors: NI
authors: Yurlova
authors: Svetlana N
authors: SN
authors: Vodyanitskaya
authors: Eisuke
authors: E
authors: Kikuchi
authors: Shuichi
authors: S
authors: Shikano
authors: Elena N
authors: EN
authors: Yadrenkina
authors: Elena I
authors: EI
authors: Zuykova
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D004032:Diet; D017753:Ecosystem; D005247:Feeding Behavior; D043143:Hepatopancreas / Q000469:parasitology; D006790:Host-Parasite Interactions; D008195:Lymnaea / Q000737:chemistry / Q000469:parasitology*; D009587:Nitrogen Isotopes / Q000032:analysis; D033661:Oocysts / Q000502:physiology; D045483:Rivers; D012800:Siberia; D014200:Trematoda / Q000502:physiology*
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes