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Tag Archive for ‘fish’

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Researchers discover a way to improve glucose regulation in fish

Many species of carnivorous fish have a difficult time metabolizing carbohydrates, resulting in hyperglycemia. In these affected species, lipids and glycogen (the storage form of glucose) build up in tissues and their growth is slowed when they are fed carbohydrate-rich diets. In addition, these fish continue to produce glucose (through gluconeogenesis) even if they consume it in their diets, which worsens their hyperglycemia. This is a major concern in the […]

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Buoyancy and Balance

Existing species of coelacanths (pictured above) are descendants of a group of fish that existed about 410 million years ago, during the early Devonian period. They can be found in the Western Indian Ocean off the coast of Indonesia. These fish are really interesting because they have very low metabolic rates. In fact, their metabolism is among the lowest of any other existing vertebrate. Even sloths are jealous of their […]

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Nitrites and noses

If you have ever had a fish tank, you may be familiar with monitoring ammonia levels in the water. Ammonia levels can rise due to overcrowding, overfeeding, as well as fish waste. Nitrite levels in the water also require monitoring as nitrite can bind to hemoglobin, which prevents oxygen from binding. In effect, by preventing oxygen from binding, the fish can succumb to hypoxia. Hannah Hughes, a graduate student working […]

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EB 2022: Adapting to a changing climate

EB 2022 was a fantastic meeting (as usual) for comparative physiology. This meeting marked the last Experimental Biology conference as each society will be hosting their own meetings going forward. I soaked up as much as I could and will be sharing what I learned at the meeting over the coming weeks. “Predicting Species Physiological Responses to a Changing Climate” The first speaker in this symposium was Dr. Hollie Putnam […]

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2022 August Krogh Distinguished Lecturer, Dr. Patricia Schulte

Each year, the Comparative and Evolutionary Physiology section of the American Physiological Society presents their highest award, the August Krogh Distinguished Lecture, to a comparative physiologist who “has made major and meritorious contributions” to the field. Dr. August Krogh (1874-1949) was a physiologist who won the Nobel Prize in Physiology or Medicine in 1920. He was very interested in zoology and joined the University of Copenhagen as an Associate Professor […]

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Surviving environmental challenges

Red tides happen when dinoflagellate algae populations increase and turn the water a shade of red due their red pigments. These algae consume oxygen in the water and release carbon dioxide and other acidic products that make the surrounding water acidic and hypoxic. These events are becoming more common with climate change. In fact, the most recent event off the coast of Sothern California occurred in 2020 and resulted in […]

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Experimental Biology 2021: Q&A with Dr. Christian Damsgaard

We are delighted to speak with Dr. Christian Damsgaard who is currently an Assistant Professor at the Aarhus Institute of Advanced Studies & Section for Zoophysiology, Aarhus University, Denmark. Dr. Damsgaard is a member of the Comparative and Evolutionary Physiology section of the American Physiological Society and he presented his research “Active Blood Acidification Greatly Enhances Oxygen Supply to the Teleost Retina” at the 2021 Experimental Biology conference today. What initially interested you in studying […]

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Extreme tolerance of dehydration stress

Talk about an extreme animal. During the rainy season annual killifish, Austrofundulus limnaeus, lay eggs that are resistant to droughts. This is an important attribute for a fish that lives in temporary pools of water. The stress-resistant embryos within the eggs literally shut down their metabolism to survive months – possibly years without water. For many fish, exposure to air (and oxygen) can cause profound oxidative stress. Remarkably, this is […]

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Anoxia tolerance in goldfish

The reason mammals are not very good at tolerating hypoxic (i.e. low oxygen) environments, is because the brain relies heavily on oxygen for metabolism. It is so stingy, it uses about 20% of the oxygen in the body to make ATP. Without oxygen, the brain has to rely on glycolysis to make ATP and this process is not good at meeting the energy requirements of the neurons, ultimately resulting in […]

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Why pigs and people absorb more sugar from their diet than fish

Researchers at the University of Saskatchewan in Canada compared how pigs and fish absorb glucose (i.e. sugar) from the diet. They did this by measuring how well glucose moves across the intestinal wall. Their findings appear in the American Journal of Physiology – Regulatory, Integrative and Comparative Physiology.  Transport of dietary glucose from the gut to the blood is facilitated by glucose transporters that pick up glucose and move it […]

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