• Corpus ID: 33159631

The physiological response of the marine platyhelminth Macrostomum lignano to 1 different environmental oxygen concentrations . 2 Short title : Response of a flatworm to oxygen variation 3 4

@inproceedings{RiveraIngraham2013ThePR,
  title={The physiological response of the marine platyhelminth Macrostomum lignano to 1 different environmental oxygen concentrations . 2 Short title : Response of a flatworm to oxygen variation 3 4},
  author={Georgina Rivera-Ingraham and Ulf Bickmeyer and Doris Abele and Georgina Rivera-Ingraham},
  year={2013}
}

• G. Rivera-Ingraham, U. Bickmeyer, +1 author G. Rivera-Ingraham
• Published 2013
• Environmental Science

Short title: Response of a flatworm to oxygen variation 3 4 G. A. Rivera-Ingraham*, U. Bickmeyer, D. Abele 5 6 Alfred-Wegener-Institute for Polar and Marine Research. 7 Dept. Functional Ecology 8 Am Handelshafen 12, 27570 Bremerhaven, Germany. 9 10 *Corresponding author: [e-mail] / [e-mail] 11 12 13 14 ABSTRACT 15 Respiration rate of meiofauna is difficult to measure, and the response to variations in 16 the environmental oxygen concentrations has so far been mainly addressed through 17 behavioral investigation. We investigated the effect of different oxygen concentrations 18 on the physiology of the marine platyhelminth Macrostomum lignano. Respiration was 19 measured using batches of 20 animals in a glass microtiter plate equipped with optical 20 oxygen sensor spots. At higher oxygen saturations (>12kPa), animals showed a clear 21 oxyconforming behavior. However, below this values, the flatworms kept respiration 22 rates constant at 0.064 ± 0.001 nmol O2·l ·h·ind down to 3 kPa po2, and this rate was 23 increased in 30% in animals that were reoxygenated after enduring a period of 1.5h in 24 anoxia. Physiological changes related to tissue oxygenation were assessed using live 25 imaging techniques with different fluorophores in animals maintained in normoxic (21 26 kPa), hyperoxic (40 kPa), near anoxic (≈0 kPa) conditions and subjected to anoxia27 reoxygenation. Ageladine-A and BCECF both indicated that pHi under near anoxia 28 increases by about 0.07 to 0.10 units. Mitochondrial membrane potential, Δψm, was 29 higher in anoxic and hyperoxic compared to normoxic conditions (JC1). Staining with 30 ROS sensitive dyes, DHE for detection of superoxide anion (O2• ) formation and C31 H2DFFDA for other ROS species aside from O2• (H2O2, HOO• and ONOO ), both 32 showed increased ROS formation following anoxia reoxygenation treatment. Animals 33 exposed to hyperoxic, normoxic and anoxic treatments displayed no significant 34 differences in O2• formation, whereas mitochondrial ROS formation as detected by C35 H2DFFDA was higher after hyperoxic exposure and lowest under near anoxia compared 36 to the normoxic control group. M. lignano seems to be a species tolerant to a wide range 37 of oxygen concentrations (being able to maintain aerobic metabolism from extremely 38 low po2 and up to hyperoxic conditions) which is an essential prerequisite for 39 successfully dealing with the drastic environmental oxygen variations that occur within 40 intertidal sediments. 41 42