In vivo exposure to high temperature compromises quality of the sperm in Colossoma macropomum.

Increases in temperature can affect the reproduction of fish by decreasing the quality of gametes for fertilization. Therefore, this study aimed to evaluate the in vivo effect of temperature on the production and sperm quality of Colossoma macropomum, which is an economically relevant species for Brazil, and other countries. Broodstock were exposed for 10 days at temperatures of 29 °C (n = 4) and 35 °C (n = 4).

Influence of hypoxia on biochemical aspects and on expression of genes related to oxygen-homeostasis of the Amazonian cichlid Astronotus ocellatus (Agassiz, 1831).

Variations in dissolved oxygen levels are common in the Amazonian aquatic environments and the aquatic organisms that inhabit these environments developed a variety of adaptive responses to deal with such conditions. Some Amazonian fish species are tolerant to low oxygen levels and the cichlid Astronotus ocellatus is one of the most hypoxia-tolerant species. Herein, we aimed to unveil the biochemical and molecular responses that A.

Hypoxia tolerance in two amazon cichlids: mitochondrial respiration and cellular metabolism adjustments are result of species environmental preferences and distribution.

The amazon fishes' responses to hypoxia seem to be related to the Amazon basin diversity of aquatic environments, which present drastic daily and seasonal variations in the dissolved oxygen concentration. Among these fishes' adaptation to hypoxia, behavioral, metabolic, physiological, and biochemical responses are well known for some species. In this work, we aimed to identify how two different aquatic environments, normoxic forest streams and hypoxic lakes, dictate the responses to hypoxia for two cichlid species, Mesonauta festivus and Aequidens pallidus.

Analysis of the transcription of genes encoding heat shock proteins (hsp) in Aedes aegypti Linnaeus, 1762 (Diptera: Culicidae), maintained under climatic conditions provided by the IPCC (Intergovernmental Panel On Climate Change) for the year 2100.

Human actions intensify the greenhouse effect, aggravating climate changes in the Amazon and elsewhere in the world. The Intergovernmental Panel on Climate Change (IPCC) foresees a global increase of up to 4.5 °C and 850 ppm CO (above current levels) by 2100.

Oxygen-dependent distinct expression of hif-1α gene in aerobic and anaerobic tissues of the Amazon Oscar, Astronotus crassipinnis.

The aquatic habitats of the Amazon basin present dramatic variation of oxygen level, and, to survive such changes, many aquatic animals developed biochemical and physiological adaptations. The advanced teleost Astronotus crassipinnis (Perciformes) is a fish tolerant to hypoxia and known to endure such naturally variable environments. Hypoxia-Inducible factor-1α (hif-1α) is among the most important and studied genes related to hypoxia-tolerance, maintaining regular cellular function and controlling anaerobic metabolism.

Does hypoxia or different rates of re-oxygenation after hypoxia induce an oxidative stress response in Cyphocharax abramoides (Kner 1858), a Characid fish of the Rio Negro?

We examined whether oxidative damage and antioxidant responses are more likely to occur during hypoxia or re-oxygenation in hypoxia-tolerant fish, and whether there is an influence of the rate of re-oxygenation. An hypoxia/re-oxygenation experiment using wild-caught Cyphocharax abramoides (Rio Negro, Brazil), was designed to answer these questions. Lipid peroxidation (MDA), a measure of oxidative damage, and antioxidant activities (superoxide dismutase (SOD), glutathione peroxidase (GPx), antioxidant capacity against peroxyl radicals (ACAP)), were measured in brain, gill and liver tissues after normoxia, 3-h hypoxia (2.

Protein synthesis is lowered by 4EBP1 and eIF2-α signaling while protein degradation may be maintained in fasting, hypoxic Amazonian cichlids .

The Amazonian cichlid is highly tolerant to hypoxia, and is known to reduce its metabolic rate by reducing the activity of energetically expensive metabolic processes when oxygen is lacking in its environment. Our objectives were to determine how protein metabolism is regulated in during hypoxia. Fish were exposed to a stepwise decrease in air saturation (100%, 20%, 10% and 5%) for 2 h at each level, and sampled throughout the experiment.