Survival of the Fishes: Research in Comparative Physiology

Animals can be cute, cuddly, weird-looking and even scary. To a comparative physiologist—someone who studies the physiological function of different species—animals can also be the key to understanding human health. Animals can provide clues about the world’s larger ecological systems.

This is becoming more and more important as climate change and pollution become two of today’s most common and harmful environmental problems. The survival of a variety of species hangs in the balance. A recent World Wildlife Fund report found that populations of more than 3,000 species of freshwater animals have dropped by 83 percent in the past several decades.

Leading comparative physiology experts met last month in New Orleans at the Comparative Physiology: Complexity and Integration conference to discuss the latest research on how animals are adapting to their changing environments. Read on to learn more about how trout, oysters and salmon are faring.

Underwater Rainbow Trout - Oncorhynchus mykiss

Credit: iStock

Climate change is creating warmer water temperatures and lower underwater oxygen levels around the world. Rainbow trout, a cold-water fish, has had to adapt to survive the significant warming of its home tributaries. Researchers from the University of British Columbia studied different strains of rainbow trout from California and Canada to learn how the fish adapted to warmer conditions. Some of the fish were naturally hardier than others and were better able to tolerate warmer temperatures and lower oxygen levels, but it wasn’t always related to where the fish came from. This example of natural variation—individual differences that make each animal or human unique—may help rainbow trout survive in the face of a changing environment.

The shell of the Olympia oyster is its own home, but it also provides a shelter for many smaller species, which creates a much healthier ecosystem. Because of oysters’

Oysters in Oyster Bed

Credit: iStock

importance in coastal ecosystems, researchers are studying whether oysters living in certain areas are more tolerant of low salt levels (salinity) in the seawater and are better able to survive climate change-associated flooding events. A research team from California State University East Bay studied Olympia oysters from different areas of the California coast and found that low salt levels stress out even the most tolerant oysters, which can threaten their lives.

Oil spills spell disaster for affected wildlife, leading to a number of long-term problems, including suffocation and poisoning, related to exposure to crude oil and its components. New research out of the University of Guelph in Canada takes a closer look at the potential effects on regional salmon populations as Canada considers expanding its crude oil export capacity.

Sockeye Salmon Jumping Up Falls

Credit: iStock

In addition to animal adaptations to climate change and pollution, researchers also discussed:

To learn more about comparative physiology, check out the Life Lines blog by Dr. Dolittle.

Erica Roth 

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