UNIVERSITY PARK, Pa. — Innovative research showing that populations of a small fish that live in both Iceland’s lakes and marine waters, respond more quickly and differently to predators after they invade new freshwater lakes, demonstrating how some animals can adapt rapidly to changes in their environments and may be able to adapt to climate change.
The study of threespined sticklebacks, spearheaded by a Penn State wildlife behavioral ecologist, involved the development of a robotic trout predator, the introduction of the scent of arctic char preying on sticklebacks, and painstaking measurements of sticklebacks’ reaction time to both those visual and olfactory predator cues. The laboratory experiments included fish that were collected in saltwater estuaries along the Icelandic coast and from both crystal clear spring-fed lakes and lakes clouded by the runoff from melting glaciers.
The researchers focused on the threespine stickleback fish because it is considered an evolutionary model due to the exceptional capacity of marine populations to repeatedly invade freshwater habitats across the Northern Hemisphere, according to Jason Keagy, assistant research professor of wildlife behavioral ecology in the College of Agricultural Sciences, who led an international team in the study.