Can sexual dimorphism lead to differences in starvation tolerance between copepod genders? Can mating activities reduce starvation tolerance in planktonic copepods?
Starvation is considered one of the main non-predatory causes of mortality in zooplankton. Planktonic copepods have sexually dimorphic traits and males and females commonly differ in body size and motile behavior. These differences between genders can lead to differences in starvation tolerance between male and females. Additionally, mating may be energetically costly and thus reduce starvation tolerance.
We investigated the influence of sexual dimorphism and mating on starvation tolerance of copepods with different feeding behaviours: ambush feeders, feeding-current feeders and cruising feeders. We found that starvation tolerance can significantly differ between copepod genders. The most pronounced difference in starvation tolerance between genders was observed in ambush feeding copepods. Our results indicate that gender differences in starvation tolerance can be partially explained by body size differences between sexes, and that mate-seeking behaviour have a minor influence on the starvation tolerance of males under prolonged starvation. The presence of the opposite gender reduced starvation tolerance in both males and females of ambushers, but not in active feeding copepods. This suggests that the energetic cost of mating behaviour in ambushers is higher than in active feeders due to the strong conflict between stationary feeding and mating activities in ambush feeding copepods. Therefore, the negative effect of mating on starvation tolerance in planktonic copepods depends on the foraging strategy.
The paper can be read here.
Mark Wejlemann Holm, Rocío Rodríguez-Torres, Hans van Someren Gréve, Benni Winding Hansen, Rodrigo Almeda*. Sex-specific starvation tolerance of copepods with different foraging strategies, Journal of Plankton Research, https://doi.org/10.1093/plankt/fby006
*Corresponding author: roal@aqua.dtu.dk