/* DATA DESCRIPTION: Citation: Kiko, Rainer; Werner, Iris; Wittmann, Astrid (2009): (Table 1) Ion concentrations in the haemolymph of Apherusa glacialis after incubation at different medium salinities. PANGAEA, https://doi.org/10.1594/PANGAEA.858995, Supplement to: Kiko, R et al. (2008): Osmotic and ionic regulation in response to salinity variations and cold resistance in the Arctic under-ice amphipod Apherusa glacialis. Polar Biology, 32(3), 393-398, https://doi.org/10.1007/s00300-008-0531-z Abstract: Amphipods living at the underside of Arctic sea ice are exposed to varying salinities due to freezing and melting, and have to cope with the resulting osmotic stress. Extracellular osmotic and ionic regulation at different salinities, thermal hysteresis, and supercooling points (SCPs) were studied in the under-ice amphipod Apherusa glacialis. The species is euryhaline, capable to regulate hyperosmotically at salinities S(R) < 30 g/kg, and osmoconforms at salinities S(R) >= 30 g/kg. Hyperosmotic regulation is an adaptation to thrive in low-salinity meltwater below the ice. Conforming to the ambient salinity during freezing reduces the risk of internal ice formation. Thermal hysteresis was not observed in the haemolymph of A. glacialis. The SCP of the species was -7.8 ± 1.9°C. Several ions were specifically downregulated ([Mg2+], [SO4]2-), or upregulated ([K+], [Ca2+]) in comparison to the medium. Strong downregulation of [Mg2+], is probably necessary to avoid an anaesthetic effect at low temperatures. Project(s): Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas (SPP1158) (URI: https://gepris.dfg.de/gepris/projekt/5472008) Funding: German Research Foundation (DFG) (URI: http://www.dfg.de/en/), grant/award no. 5472008: Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas (URI: https://gepris.dfg.de/gepris/projekt/5472008) Coverage: MEDIAN LATITUDE: 87.831150 * MEDIAN LONGITUDE: -170.236750 * SOUTH-BOUND LATITUDE: 87.829600 * WEST-BOUND LONGITUDE: -170.741000 * NORTH-BOUND LATITUDE: 87.832700 * EAST-BOUND LONGITUDE: -169.732500 DATE/TIME START: 2007-09-02T11:12:00 * DATE/TIME END: 2007-09-02T23:45:00 MINIMUM ELEVATION: -3995.0 m * MAXIMUM ELEVATION: -3992.0 m Event(s): PS70/328-1 * LATITUDE START: 87.832700 * LONGITUDE START: -170.741000 * LATITUDE END: 87.829600 * LONGITUDE END: -169.732500 * DATE/TIME START: 2007-09-02T11:12:00 * DATE/TIME END: 2007-09-02T23:45:00 * ELEVATION START: -3992.0 m * ELEVATION END: -3995.0 m * LOCATION: Arctic Ocean * CAMPAIGN: ARK-XXII/2 (PS70 SPACE DAMOCLES) (URI: https://doi.org/10.2312/BzPM_0579_2008) * BASIS: Polarstern (URI: https://doi.org/10.17815/jlsrf-3-163) * METHOD/DEVICE: Ice station (ICE) Comment: Sample numbers are n = 2 to 4 Parameter(s): Experimental treatment (Exp treat) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) * COMMENT: salinity of medium in g/kg Sample type (Samp type) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Potassium ion [mmol/l] (K+) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Haemolymph, potassium ion [mmol/l] (K+ (ha)) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Magnesium ion [mmol/l] (Mg2+) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Haemolymph, magnesium ion [mmol/l] (Mg2+ (ha)) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Calcium ion [mmol/l] (Ca2+) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Haemolymph, calcium ion [mmol/l] (Ca2+ (ha)) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Sulfate ion [mmol/l] ([SO4]2-) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Haemolymph, sulfate ion [mmol/l] ([SO4]2- (ha)) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Sodium ion [mmol/l] (Na+) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Haemolymph, sodium ion [mmol/l] (Na+ (ha)) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Chloride ion [mmol/l] (Cl-) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Haemolymph, chloride ion [mmol/l] (Cl- (ha)) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) Sum [mmol/l] (Sum) * PI: Kiko, Rainer (https://orcid.org/0000-0002-7851-9107, rkiko@geomar.de) License: Creative Commons Attribution 3.0 Unported (CC-BY-3.0) (URI: https://creativecommons.org/licenses/by/3.0/) Size: 110 data points */ Exp treat Samp type K+ [mmol/l] K+ (ha) [mmol/l] Mg2+ [mmol/l] Mg2+ (ha) [mmol/l] Ca2+ [mmol/l] Ca2+ (ha) [mmol/l] [SO4]2- [mmol/l] [SO4]2- (ha) [mmol/l] Na+ [mmol/l] Na+ (ha) [mmol/l] Cl- [mmol/l] Cl- (ha) [mmol/l] Sum [mmol/l] 30 medium 8.8 48.1 9.6 27.3 432.5 510.4 1036.6 30 Apherusa glacialis haemolymph 24.8 16.2 16.6 6.2 432.5 510.4 1007.0 30 Apherusa glacialis haemolymph 18.4 12.1 14.9 5.5 432.5 510.4 993.8 30 Apherusa glacialis haemolymph 22.9 10.4 14.9 30 Apherusa glacialis haemolymph 14.8 7.6 10.4 40 medium 13.2 76.6 14.7 37.2 574.0 661.4 1377.1 40 Apherusa glacialis haemolymph 26.8 22.2 19.2 9.4 574.0 661.4 1313.0 40 Apherusa glacialis haemolymph 18.8 15.6 19.7 8.3 574.0 661.4 1298.0 40 Apherusa glacialis haemolymph 22.2 14.8 17.8 50 medium 18.6 96.6 19.3 45.0 759.6 827.1 1766.2 50 Apherusa glacialis haemolymph 11.8 10.8 21.2 22.8 759.6 827.1 1653.3 50 Apherusa glacialis haemolymph 23.2 19.3 29.1 21.6 759.6 827.1 1679.9 50 Apherusa glacialis haemolymph 13.4 12.1 20.9 28.0 759.6 827.1 1661.1 50 Apherusa glacialis haemolymph 29.3 43.9 21.6