La Sierra marine scientist lands NSF grant to study fish adaptation

Lloyd Trueblood, a biology professor and physiologist at La Sierra University together with two East Coast researchers recently received a $650,000 grant from the National Science Foundation to investigate this hypothesis and answer other questions. La Sierra’s portion, $163,000, will be used to cover equipment costs, a student researcher stipend and travel costs for Trueblood and students to attend conferences.

“At this point, we’re purchasing all the toys,” joked Trueblood during a recent interview in his lab at Price Science Complex. The grant was funded in July and Trueblood’s analysis is expected to begin during winter and spring quarters this year.

Trueblood’s “toys” include a Shimadzu UV-1800 research-grade spectrophotometer that will shine light through enzyme samples to detect how much light makes it through the sample. The greater the level of pigment change that appears as the light passes through, the more enzyme activity is taking place. “It allows us to measure the amount of aerobic and anaerobic enzyme activity that exists in the muscles,” said Trueblood. Enzymes control aerobic respiration, which requires oxygen, and anaerobic respiration, which does not require oxygen. In both cases, enzyme activity produces energy that can be used for muscle movement.

The bluegill, a type of sunfish, lives in lakes, ponds, streams and rivers around the United States. Some bluegill live among weeds and rocks at the bottom of bodies of water, while others spend their existence swimming up in the water column. The fish are not transient between the two environments, and scientists believe they are developing different body shapes that allow them to function best in their respective environments. The fish that live higher up in the water tend to be longer and narrower in shape, while their counterparts at the bottom have developed a flatter appearance and more robust pectoral muscles.

Their muscle physiology may also be adapted for the type of swimming they do in their environment. Those that live up in the water column may be adapted for burst swimming, and those living among the weeds would be adapted for maneuvering around them.

“We’re seeing a clear case of the environment driving adaptation,” Trueblood said. “This research can inform how much change and what type of change occurs over a timeframe, and how much of an impact the environment has on body form and function.”

Trueblood is working on the bluegill research project with scientists Shannon Gerry at Fairfield University in Connecticut and David Ellerby at Wellesley College in Massachusetts. Gerry and Ellerby are collecting fish from lakes in and around the Wellesley College campus and later this year will ship muscle tissue samples frozen in dry ice to Trueblood for analysis in his lab. Trueblood and his student researchers will grind up the fish muscle tissue, infuse it with pigment and process it through the spectrophotometer.

Gerry and Ellerby will conduct additional analysis that includes placing bluegill fish in tanks of water with treadmill-like swim tunnels to observe how they swim under various conditions. The scientists will ultimately collect about 100 fish from different environments for various analyses.

Trueblood became involved in the research project idea in 2011 while attending a meeting in Utah of the Society for Integrative and Comparative Biology where Ellerby gave a talk. Gerry and Ellerby had already begun to study the fish’s structural and behavioral components, and Trueblood suggested extending the research to determine impacts of the environment on adaptation of muscle physiology. The grant-funded study will carry on through 2018. The scientists will pool their data sets and ultimately publish their findings.