David H. Bennett
David Deslauriers
Lars G. Rudstam
Steven R. Chipps
2022
<p><span>The freshwater opossum shrimp </span><i>Mysis diluviana</i><span> can undergo extensive diel vertical migration (DVM) to feed in shallow, prey rich strata at night. Bright moonlight limits their night-time migration presumably due to predator avoidance. Using a linked, foraging-bioenergetics model, we evaluated the cost of avoiding predators by simulating the effects of prey density, water temperature, and light intensity on daily feeding and growth of </span><i>M. diluviana</i><span> in Lake Pend Oreille, Idaho, USA. We found that when mysid distribution was not limited by moonlight intensity, simulated food consumption (10.3 J day</span><sup>−1</sup><span>) increased 1.6-fold compared to estimated consumption (6.1 J day</span><sup>−1</sup><span>) based on their observed, vertical distribution. Moreover, simulated growth of mysids (0.61 mg day</span><sup>−1</sup><span>) increased 74% compared to that estimated from observed distribution patterns (0.35 mg day</span><sup>−1</sup><span>), when they were located in deeper, darker strata. Given recent insights into partial DVM by </span><i>M. diluviana</i><span>, we note that proximate factors associated with predator avoidance in pelagic (light availability) and benthic (hunger level, body size and reproductive status) habitats may convey complimentary benefits to </span><i>M. diluviana</i><span> fitness by reducing predation mortality and increasing metabolic efficiency.</span></p>
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10.1007/s10750-022-04832-w
en
Springer Nature
The cost of avoiding predators: A bioenergetic analysis of diel vertical migration by the opossum shrimp Mysis diluviana
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