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SOCIETY FOR INTEGRATIVE AND COMPARATIVE BIOLOGY
2021 VIRTUAL ANNUAL MEETING (VAM)
January 3 - Febuary 28, 2021

Meeting Abstract

P5-11  Sat Jan 2  Does a prolonged exposure to low pH water and low food quality affect juvenile Dungeness crab behavior? Hayes, HG*; Street, E; Manos, SA; Thompson, N; Schram , JB; Galloway, AWE; University of Oregon, Oregon Institute of Marine Biology; University of Oregon, Oregon Institute of Marine Biology; North Bend High School ; University of Oregon, Oregon Institute of Marine Biology; University of Oregon, Oregon Institute of Marine Biology; University of Oregon, Oregon Institute of Marine Biology; University of Oregon, Oregon Institute of Marine Biology hannahhayes858@gmail.com

Increases in anthropogenic carbon is contributing to low pH in the ocean, referred to generally as ocean acidification. Low pH water affects the behavior and sensory systems of crustaceans, but little is currently known about the effects of ocean acidification on post-settlement juvenile life history stage in Dungeness crab (Metacarcinus magister), particularly their perception of food chemical cues. We captured crab megalopae using a light trap, and settled juvenile crab were maintained in ambient lab conditions on a diet of fresh clam meat until they were second instars prior to placement in the experimental treatments. To understand the foraging and pH sensing behavior of juvenile crabs, and how this interacts with their nutritional status, we exposed recently settled second instar juveniles to either ambient pH or reduced pH for six weeks while providing low and high quality diets to all crabs. After the 6-week experiment, we introduced crabs into a foraging and sensing pH behavior experiment. In the foraging experiment, we placed crabs in a behavior arena with unidirectional flow and a food pellet upstream from the crab, with either ambient pH or a reduced pH water flowing through the arena. We measured the food discovery and handling time in 300 second trials. For our sensing pH experiment, we used a two-current choice flume with an ambient pH and a reduced pH, providing a choice between the two, and measured the amount of time individuals spent in each side of the arena in 300 second trials. We hypothesize that crabs from the ambient pH treatment will find food faster, and in the choice trials crabs will spend more time in the ambient pH water.