Temperature and dissolved oxygen determine submersion time in aquatic beetle Peltodytes callosus (Coleoptera: Haliplidae)

Authors: Kate Boersma, Tyler Banks, Rachel Kincaid, Patrick Carroll

Year: 2017 (xlix)

Abstract

Global climate change affects aquatic habitats in a number of ways that pose challenges for aquatic insect populations Increasing water temperature and corresponding decreases in dissolved oxygen can impact respiratory behaviors, even in air-breathing aquatic taxa Crawling water beetles (Coleptera: Haliplidae) exhibit a combined respiratory strategy that employs a subelytral air store that is periodically replenished at the water surface The frequency at which beetles must surface to replenish the bubble is determined both by oxygen consumption and by the capacity of the air store to uptake oxygen from the surrounding water via diffusion However, little is known of how changes in water temperature and dissolved oxygen will affect submersion time We investigated this question in Peltodytes callosus, a species of crawling water beetle that is widely distributed across the American West We manipulated temperature and dissolved oxygen to mimic changes associated with drought and recorded the time between surfacing events We found that beetles stayed submerged for shorter durations in response to both increasing water temperature and decreasing dissolved oxygen Our results suggest that beetles may be able to modify their surfacing behavior to respond to climate-induced changes in water quality