呼吸窘迫 z-bo 2021-01-06 379

　　A new study conducted by researchers at Radboud University in collaboration with international researchers from McGill University (Canada) and the University of Montana (USA) shows that large fish suffer from respiratory distress faster in warm water than smaller species. This means that the warming of the ocean caused by climate change will affect the respiratory physiology of large fish, and ultimately may affect the physiological performance, survival rate and size of the fish. The researchers reached this conclusion with the help of a new model that can more accurately calculate the effects of body temperature, activity and body size on oxygen absorption.

　　Oxygen is essential for animals to produce energy needed for growth, reproduction and survival. The absorption of oxygen is related to factors such as body temperature or body size. Compared with large animals of the same species, small animals consume relatively more oxygen. We also know that fish that live in warmer regions need more oxygen than cold regions.

　　 complex interaction

　　 Biologists use their knowledge of oxygen absorption to predict how animals respond to changes in the outside world (such as global warming). For example, as the ocean warms, will fish migrate to cooler areas? Or will they stop growing as soon as possible to prevent respiratory distress, although this may have a significant impact on their fertility?

　　 In order to make accurate predictions, biologists struggle with the interaction between size, temperature and oxygen uptake. Lead author Juan Rubalcaba (McGill and Montana) said: “This is because this relationship affects each other and complicates the investigation.” “For example, if warming increases fish The water surrounding its g will run out of oxygen, which in turn will hinder the oxygen uptake through the via. Therefore, the fish must ventilate theirs, but the efficiency of this ventilation depends on the water temperature and body size."

　　 hypoxia

　　 In order to better understand how these mechanisms work, researchers have developed a model that can directly simulate the effects of oxygen conditions around the models. Radboud biologist Wilco Verberk explained: "We compared the oxygen uptake predictions in the new model with actual measurements of more than 200 fish species. These predictions are in line with empirical models. It’s a perfect match, and we noticed that large fish and oxygen limitation in warm water are more likely to occur and are at high activity levels."

　　 Rubalcaba: “Earlier models focused on oxygen absorption when animals are at rest or at low temperatures, but our model shows that if all three factors are taken into account, oxygen may be limited.”

　　The new model has greater ecological significance than earlier models that focused on resting fish. Weber: "Finding food, growing, reproducing or escaping from predators requires extra energy, and therefore oxygen. In particular, due to warming lakes, oceans and rivers, the activities of larger individuals in fish will be stressed. This It will reduce their ability to deal with climate change."