Felix Christopher Mark

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—The hypothesis of an oxygen-limited thermal tolerance was tested in the Antarctic teleost Pachycara brachycephalum. With the use of flow-through respirometry, in vivo 31 P-NMR spectroscopy, and MRI, we studied energy metabolism, intracellular pH (pH i), blood flow, and oxygenation between 0 and 13°C under normoxia (PO2: 20.3 to 21.3 kPa) and hyperoxia(More)
In various phyla of marine invertebrates limited capacities of both ventilatory and circulatory performance were found to set the borders of the thermal tolerance window with limitations in aerobic scope and onset of hypoxia as a first line of sensitivity to both cold and warm temperature extremes. The hypothesis of oxygen limited thermal tolerance has(More)
Climate variability has long been seen to influence the structure and functioning of marine, terrestrial and freshwater ecosystems. Fluctuations in marine communities and populations have been attributed to the impact of decadal-scale variations in the coupled ocean–atmosphere system (Cushing 1982, Beamish 1995, Bakun 1996, O'Brien et al. 2000, Finney et(More)
Mechanisms that affect thermal tolerance of ectothermic organisms have recently received much interest, mainly due to global warming and climate-change debates in both the public and in the scientific community. In physiological terms, thermal tolerance of several marine ectothermic taxa can be linked to oxygen availability, with capacity limitations in(More)
Antarctic notothenioid fish are characterized by their evolutionary adaptation to the cold, thermostable Southern Ocean, which is associated with unique physiological adaptations to withstand the cold and reduce energetic requirements but also entails limited compensation capacities to environmental change. This study compares the capacities of(More)
Mitochondrial plasticity plays a central role in setting the capacity for acclimation of aerobic metabolism in ectotherms in response to environmental changes. We still lack a clear picture if and to what extent the energy metabolism and mitochondrial enzymes of Antarctic fish can compensate for changing temperatures or PCO2 and whether capacities for(More)
The cuttlefish Sepia officinalis expresses several hemocyanin isoforms with potentially different pH optima, indicating their reliance on efficient pH regulation in the blood. Ongoing ocean warming and acidification could influence the oxygen-binding properties of respiratory pigments in ectothermic marine invertebrates. This study examined whether S.(More)
This paper is the result of an international initiative and is a first attempt to develop guidelines for the care and welfare of cephalopods (i.e. nautilus, cuttlefish, squid and octopus) following the inclusion of this Class of ∼700 known living invertebrate species in Directive 2010/63/EU. It aims to provide information for investigators, animal care(More)
Transgenerational effects can buffer populations against environmental change, yet little is known about underlying mechanisms, their persistence or the influence of environmental cue timing. We investigated mitochondrial respiratory capacity (MRC) and gene expression of marine sticklebacks that experienced acute or developmental acclimation to simulated(More)
Uncoupling proteins (UCP), capable of increasing proton leakage across the inner mitochondrial membrane, may play a role in the temperature-dependent setting of energy turnover in animals (and their mitochondria). Therefore, the genes and expression of fish UCP were investigated in the Antarctic eelpout Pachycara brachycephalum and a temperate confamilial(More)