title: Effects of Maternally-Transferred Methylmercury on Stress Physiology in Northern Water Snake (Nerodia sipedon) Neonates.
abstract: Biomagnification of methylmercury in aquatic systems can cause elevated tissue mercury (Hg) and physiological stress in top predators. Mercury is known to affect stress hormone levels in mammals, birds and fish. In this study, the effects of maternally-transferred methylmercury on the stress physiology of Northern Water Snake (Nerodia sipedon) neonates were tested. Gravid females were dosed via force-fed capsules during late gestation with 0, 0.01, or 10 µg methylmercury per gram of body mass. Plasma corticosterone levels and leukocyte differentials were analyzed in baseline and confinement-stressed neonates from all dose levels. Neither Hg nor confinement stress had a significant effect on leukocyte differentials nor was Hg related to corticosterone levels. However, stress group neonates showed lower heterophil/lymphocyte ratios and this study was the first to show that neonate N. sipedon can upregulate CORT in response to stress. These results indicate that N. sipedon may be somewhat tolerant to Hg contamination.
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.|Department of Zoology, Oklahoma State University, Stillwater, OK, 74075, USA.
authors.forename: J Patrick W
authors.initials: JP
authors.lastname: Cusaac
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
authors.forename: Victoria
authors.initials: V
authors.lastname: Kremer
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
authors.forename: Raymond
authors.initials: R
authors.lastname: Wright
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
authors.forename: Cassandra
authors.initials: C
authors.lastname: Henry
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
authors.forename: Ryan R
authors.initials: RR
authors.lastname: Otter
authors.affiliation: Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA. frank.bailey@mtsu.edu.
authors.forename: Frank C
authors.initials: FC
authors.lastname: Bailey
mesh_terms: D000818:Animals; D001717:Birds; D017812:Colubridae / Q000502:physiology*; D003345:Corticosterone / Q000097:blood; D005260:Female; D005399:Fishes; D008767:Methylmercury Compounds / Q000633:toxicity*; D011247:Pregnancy; D013312:Stress, Physiological / Q000187:drug effects*
chemical_list: D008767:Methylmercury Compounds; D003345:Corticosterone
keywords: Corticosterone; Leukocytes; Maternal transfer; Methylmercury; Neonate; Reptile