Swimming kinematics of Eurytemora affinis (Copepoda, Calanoida) reproductive stages and differential vulnerability to predation of larval Dicentrarchus labrax (Teleostei, Perciformes)
Résumé
In egg-bearing copepods, the ovigerous females are reported to be more vulnerable to predators. However, the underlying mechanistic details of increased vulnerability are not yet well understood. We studied the predator-prey interaction between the copepod prey Eurytemora affinis and a predator, post-larvae of the sea bass Dicentrarchus labrax. Standard video techniques have been used to quantify the predation efficiency of larval sea bass and to record the two-dimensional swimming behavior of the different reproductive stages (males, non-ovigerous females and ovigerous females) of E. affinis in both the absence and presence of predators. Our results revealed that ovigerous females suffered higher mortality rates than either non-ovigerous females or males. Body size and swimming speed seemed to be the main determinants of prey conspicuousness to predators. In the light of published data, we conclude that acute vulnerability of E. affinis ovigerous females to planktivorous predators is not necessarily harmful at the population level.
Domaines
Océanographie
Origine : Publication financée par une institution