Research on the high energetic cost of color change in octopuses, conducted by Kirt Onthank, biology professor at Walla Walla University (WWU), and WWU graduate Sofie Sonner, has been published in one of the world’s most prestigious and cited scientific journals, Proceedings of the National Academy of Sciences (PNAS).

Onthank’s and Sonner’s findings have sparked interest in the scientific community, and within hours of the initial PNAS publication, Popular Science and ScienceAlert also published stories about the research. 

Sonner partnered with Onthank on this research as part of her master’s in biology thesis at WWU. According to the study, color-changing camouflage in octopuses requires exceptionally high metabolic costs. Sonner and Onthank estimated the metabolic demand associated with color-changing chromatophore organs in ruby octopuses (Octopus rubescens). 

The results, released in an article titled “High energetic cost of color change in octopuses” in PNAS on Nov. 18, 2024, suggested that the energy required to activate all a ruby octopus’s chromatophores simultaneously was almost as high as the resting metabolic rate associated with all other physiological processes. 

“Though octopuses make color change look effortless, it isn’t for them,” said Onthank. The high energetic costs associated with the chromatophore system would likely put pressure on octopuses to minimize such costs, potentially contributing to the use of dens or nocturnal lifestyles in some octopus species and reductions in chromatophore systems among deep-sea species

Onthank, himself a graduate of WWU, has long been fascinated by cephalopods and has published numerous peer-reviewed articles on octopuses’ energy budgeting, burrowing activity of octopuses, eye lenses of squid and a deep-sea octopus species, and the impacts of ocean acidification on octopus physiology. He was featured as an octopus expert for NBC National News in April and is known as a go-to octopus expert and educator on TikTok. 

Undergraduate and master’s students at the university are invited to join Onthank in his research if interested. Much of it is conducted at WWU’s Rosario Beach Marine Laboratory near Anacortes, Wash. “I typically have an octopus or two in my lab during the school year that students work with, and many octopuses at Rosario during the summer,” he said. 

Rosario Beach Marine Laboratory is a powerhouse biological research center. There, students have participated in important research on harmful algae blooms and detecting their presence quickly, seagrass wasting disease, oxygen consumption of nudibranchs, the development of motion-detecting underwater cameras, and hibernation and organ regeneration in sea cucumbers. Owned by Walla Walla University since 1954, Rosario Beach Marine Laboratory has trained nearly 3,000 undergraduate and graduate students in marine, field, and experimental sciences.

Intentional collaboration between professors, students, and academic departments makes exciting discoveries like this possible, Onthank says. In recent years, students from Walla Walla University’s Edward F. Cross School of Engineering have contributed to serious biological research. “Our engineers collaborate with marine biologists to develop ocean research and exploration tools. This is essential for cutting-edge marine biology.” 

Innovative research like this not only contributes to the scientific community but also helps train student scientists interested in various professions. The university’s Department of Biological Sciences offers undergraduate degrees in biology, biochemistry, bioengineering, biophysics, and marine biology. WWU is also the only private university in the Pacific Northwest to offer a master’s degree in biology.

Founded in 1892 and affiliated with the Seventh-day Adventist Church, WWU is a private institution serving 1,401 students across four campuses.

The original article was published on the North American Division website.