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Ovigerity, selective predation, and variable diel vertical migration in Euchaeta elongata (Copepoda: Calanoida)
1School of Oceanography, University of Washington, WB-10, 98195, Seattle, WA, USA.
Oecologia
|March 18, 2017
Summary
Female Euchaeta elongata copepods exhibit different diel vertical migration (DVM) behaviors based on reproductive status. Ovigerous females avoid predators by staying deep, while non-ovigerous females migrate to shallower waters.
Area of Science:
- Marine biology
- Zooplankton ecology
- Behavioral ecology
Background:
- Diel vertical migration (DVM) is a key behavior in marine zooplankton.
- Reproductive status can influence DVM patterns in copepods.
- Predation risk and demographic costs shape DVM strategies.
Purpose of the Study:
- Analyze DVM patterns of Euchaeta elongata females.
- Investigate predator selectivity for different female morphs.
- Assess the demographic consequences of DVM behavior.
Main Methods:
- Statistical analysis of existing Euchaeta elongata distribution data.
- Experimental feeding trials with Pacific herring (predator).
- Life table analysis to model population growth.
Main Results:
- Non-ovigerous females showed strong DVM; ovigerous females exhibited weak or no DVM.
- Pacific herring preferentially preyed on ovigerous females.
- Non-migratory ovigerous females face demographic disadvantages due to delayed egg development.
Conclusions:
- Ovigerous E. elongata remain at depth to avoid predation, despite delayed egg development.
- This predator avoidance strategy provides a significant survival advantage.
- DVM behavior in E. elongata is a complex trade-off between predation and reproduction.
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