Publications by authors named "Per Hjelmstedt"
Striped catfish (Pangasianodon hypophthalmus) use air-breathing and aquatic surface respiration when exposed to severe aquatic hypercarbia.
J Exp Zool A Ecol Integr Physiol
November 2021
Article Synopsis
- The study focused on how striped catfish (Pangasianodon hypophthalmus) use air-breathing to handle high levels of carbon dioxide (hypercarbia) in water and how this behavior varies with different exposure methods.
- Results showed that the fish can tolerate high hypercarbia, maintaining stable gill ventilation, heart rate, and blood pressure even at elevated CO2 levels.
- Individual fish showed varying responses to air-breathing, with the method of exposure affecting when they started to breathe air; air-breathing generally began at lower CO2 levels during a step-wise approach compared to a progressive one.
Article Synopsis
- Bio-logging devices can help researchers study the behavior of wild animals, but implanting them involves invasive surgeries that can cause stress and health issues.
- The study hypothesized that enrofloxacin, a common medication given after surgery, would improve recovery in rainbow trout after heart rate bio-logger implantation.
- Contrary to expectations, trout treated with enrofloxacin showed longer recovery times, higher heart rates, and increased inflammation, emphasizing the need for careful surgical practices and post-operative care for animal welfare and research reliability.
In seawater, rainbow trout () drink and absorb water through the gastrointestinal tract to compensate for water passively lost to the hyperosmotic environment. Concomitantly, they exhibit elevated cardiac output and a doubling of gastrointestinal blood flow to provide additional O to the gut and increase convective flux of absorbed ions and water. Yet, it is unknown how warming waters, which elevate tissue O demand and the rate of diffusion of ions and water across the gills (i.
View Article and Find Full Text PDFThe fish gut is responsible for numerous potentially energetically costly processes, yet little is known about its metabolism. Here, we provide the first measurements of aerobic metabolism of the gut in a teleost fish by measuring gut blood flow, as well as arterial and portal venous oxygen content. At 10°C, gut oxygen uptake rate was 4.
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