title: Toxicokinetics of selenium in the slider turtle, Trachemys scripta.
abstract: Selenium (Se) is an essential element that can be harmful for wildlife. However, its toxicity in poikilothermic amniotes, including turtles, remains poorly investigated. The present study aims at identifying selenium toxicokinetics and toxicity in juvenile slider turtles (age: 7 months), Trachemys scripta, dietary exposed to selenium, as selenomethionine SeMet, for eight weeks. Non-destructive tissues (i.e. carapace, scutes, skin and blood) were further tested for their suitability to predict selenium levels in target tissues (i.e. kidney, liver and muscle) for conservation perspective. 130 juvenile yellow-bellied slider turtles were assigned in three groups of 42 individuals each (i.e. control, SeMet1 and SeMet2). These groups were subjected to a feeding trial including an eight-week supplementation period SP 8 and a following 4-week elimination period EP 4 . During the SP8, turtles fed on diet containing 1.1 ± 0.04, 22.1 ± 1.0 and 45.0 ± 2.0 µg g(-1) of selenium (control, SeMet1 and SeMet2, respectively). During the EP4, turtles fed on non-supplemented diet. At different time during the trial, six individuals per group were sacrificed and tissues collected (i.e. carapace, scutes, skin, blood, liver, kidney, muscle) for analyses. During the SP8 (Fig. 1), both SeMet1 and SeMet2 turtles efficiently accumulated selenium from a SeMet dietary source. The more selenium was concentrated in the food, the more it was in the turtle body but the less it was removed from their tissues. Moreover, SeMet was found to be the more abundant selenium species in turtles' tissues. Body condition (i.e. growth in mass and size, feeding behaviour and activity) and survival of the SeMet1 and SeMet2 turtles seemed to be unaffected by the selenium exposure. There were clear evidences that reptilian species are differently affected by and sensitive to selenium exposure but the lack of any adverse effects was quite unexpected. Fig. 1 Design of the feeding trial. T, Time of tissues collection in weeks. The feeding trial included a supplementation period of 8 weeks (i.e. SP8) followed by an elimination period of 4 weeks (i.e. EP4). Six turtles from each turtle group (i.e. control, SeMet1 and SeMet2) were sacrifice at each collection time, from T1 to T12. At T0, four turtles were sacrificed.
authors.affiliation: Laboratory of Oceanology, MARE Center - B6c University of Liege, 4000, Liège, Belgium.
authors.forename: Christelle
authors.initials: C
authors.lastname: Dyc
authors.affiliation: Inorganic Analytical Chemistry, Laboratory of Mass Spectrometry - B6c University of Liege, 4000, Liege, Belgium.
authors.forename: Johann
authors.initials: J
authors.lastname: Far
authors.affiliation: Faculty of Veterinary Medicine; Clinic for Birds, Rodents and Rabbits, University of Liege, Boulevard de Colonster 180, B42, 4000, Liege, Belgium.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Gandar
authors.affiliation: Protection and Health in the Workplace (SUPHT) - B12b University of Liege, 4000, Liège, Belgium.
authors.forename: Anastassios
authors.initials: A
authors.lastname: Poulipoulis
authors.affiliation: Laboratory of Oceanology, MARE Center - B6c University of Liege, 4000, Liège, Belgium.
authors.forename: Anais
authors.initials: A
authors.lastname: Greco
authors.affiliation: Inorganic Analytical Chemistry, Laboratory of Mass Spectrometry - B6c University of Liege, 4000, Liege, Belgium.
authors.forename: Gauthier
authors.initials: G
authors.lastname: Eppe
authors.affiliation: Laboratory of Oceanology, MARE Center - B6c University of Liege, 4000, Liège, Belgium. krishna.das@ulg.ac.be.
authors.forename: Krishna
authors.initials: K
authors.lastname: Das
mesh_terms: D000818:Animals; D004032:Diet; D007668:Kidney; D008099:Liver; D009132:Muscles; D012643:Selenium / Q000378:metabolism*; D066007:Toxicokinetics; D014426:Turtles / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D014874:Water Pollutants, Chemical; D012643:Selenium
keywords: In vivo exposure; Selenium; Selenium species; Trachemys scripta; Turtles