Dietary carbohydrates induce a higher SDA than lipids in rainbow trout (Oncorhynchus mykiss) based on environmental temperature.

As global temperatures increase so do the needs to investigate how the energy metabolism of fish responds to a broad range of thermal condition. Limited resources make it additionally important to use them sustainably in the feeds for aquaculture. Here we investigated the use of three different carbohydrate to lipid ratios (1:1; 1: 0.

The thermal dependence of the protein-sparing effect in rainbow trout (Oncorhynchus mykiss, Walbaum 1792).

The authors performed an instantaneous bioenergetic study with rainbow trout (Oncorhynchus mykiss) of 206.3 g ± 2.9 g in a group respirometer of nine 250 l tanks at five different water temperatures (12, 14, 16, 18, 20°C) to determine the optimal thermal condition for a maximal visualization of the protein-sparing effect.

SDA coefficient is temperature dependent in rainbow trout (Oncorhynchus mykiss, Walbaum 1792) in a practical approach using group respirometry.

Rising global temperatures have raised the need for detailed knowledge of the effects of rising temperatures on the physiology of animals used in aquaculture. Here we used a multifactorial bioenergetic approach using groups of rainbow trout (Oncorhynchus mykiss) with an average single fish weight of 183.75 g ± 0.

Migrating curlews on schedule: departure and arrival patterns of a long-distance migrant depend on time and breeding location rather than on wind conditions.

Background: Departure decisions in long-distance migratory bird species may depend on favourable weather conditions and beneficial resources at the destination location, overarched by genetic triggers. However, few studies have tried to validate the significance of these three concepts simultaneously, and long-term, high-resolution tagging datasets recording individual movements across consecutive years are scarce. We used such a dataset to explore intraspecific and intra-individual variabilities in departure and arrival decisions from/to wintering grounds in relation to these three different concepts in bird migration.

Divergent gene expression in the gills of juvenile turbot (Psetta maxima) exposed to chronic severe hypercapnia indicates dose-dependent increase in intracellular oxidative stress and hypoxia.

Elevated concentrations of carbon dioxide are a common stressor for fish and other aquatic animals. In particular, intensive aquaculture can impose prolonged periods of severe environmental hypercapnia, manifold exceeding CO concentrations of natural habitats. In order to cope with this stressor, gills are essential and constitute the primary organ in the acclimatization process.

The effect of diet, temperature and intermittent low oxygen on the metabolism of rainbow trout.

An automated respirometer system was used to measure VO2, protein catabolism as ammonia quotient and the energy budget to evaluate whether the crude protein content of a standard protein (SP) diet (42·5 %) or a high-protein (HP) diet (49·5 %) influences metabolism in rainbow trout under challenging intermittent, low dissolved oxygen concentrations. In total, three temperature phases (12, 16, 20°C) were tested sequentially, each of which were split into two oxygen periods with 5 d of unmanipulated oxygen levels (50-70 %), followed by a 5d manipulated oxygen period (16.00-08.

Distribution analysis of hydrogenases in surface waters of marine and freshwater environments.

Background: Surface waters of aquatic environments have been shown to both evolve and consume hydrogen and the ocean is estimated to be the principal natural source. In some marine habitats, H(2) evolution and uptake are clearly due to biological activity, while contributions of abiotic sources must be considered in others. Until now the only known biological process involved in H(2) metabolism in marine environments is nitrogen fixation.

TFA and EPA productivities of Nannochloropsis salina influenced by temperature and nitrate stimuli in turbidostatic controlled experiments.

The influence of different nitrate concentrations in combination with three cultivation temperatures on the total fatty acids (TFA) and eicosapentaenoic acid (EPA) content of Nannochloropsis salina was investigated. This was done by virtue of turbidostatic controlled cultures. This control mode enables the cultivation of microalgae under defined conditions and, therefore, the influence of single parameters on the fatty acid synthesis of Nannochloropsis salina can be investigated.

Determination of DPPH Radical Oxidation Caused by Methanolic Extracts of Some Microalgal Species by Linear Regression Analysis of Spectrophotometric Measurements.

The demonstrated modified spectrophotometric method makes use of the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical and its specific absorbance properties. Theabsorbance decreases when the radical is reduced by antioxidants. In contrast to otherinvestigations, the absorbance was measured at a wavelength of 550 nm.