Brain evolution in threespine stickleback fish (Gasterosteus aculeatus) from recently transplanted and long-established lake populations in Cook Inlet, Alaska

Authors: Kinza Yasmeen, Peter Park

SUNY Campus: Farmingdale State College

Presentation Type: Poster

Location: Old Union Hall

Presentation #: 21

Timeslot: Session B 10:15-11:15 AM

Abstract: This project analyzes brain evolution in lake populations of Alaskan threespine stickleback (Gasterosteus aculeatus) that were recently founded by sea-run stickleback. Stickleback are small fish species that have a life cycle much like salmon, where they are born in freshwater, travel out to sea to mature, and then return to freshwater to breed. Sometimes, when stickleback return to freshwater, they will breed in lakes that may get landlocked, after which the sea run forms evolve into freshwater forms over many generations. Several lakes in southcentral Alaska have been recently founded by sea-run populations - some naturally founded and some founded intentionally introduced by humans. This study explores the impact of time on stickleback brain evolution because these newly transplanted stickleback populations are recent and have known founding years. For this study, samples were collected from Loberg Lake founded in 1985, Cheney Lake founded in 2009, Warfle Lake founded in 2019, and three lakes along Seward Highway (one founded in 1914 and two others in 1966). A sea-run ancestral population (Rabbit Sough) and a pair of long-established lake populations (likely thousands of years old), were analyzed to provide context for any trends in brain evolution discovered in the “new” lake populations. In addition, lab reared version of some populations were also studied. Broadly, we seek to explore patterns and rates of change in brain evolution to be generalized to other fishes.