Effect of mate guarding on the swimming behaviour of female Euterpina acutifrons (Copepoda, Harpacticoida)

Abstract

During copulation bouts, Euterpina acutifrons males grasp females and cling for extended periods as a form of mate guarding. The present study assessed the effects of such mate guarding on the swimming behaviour of grasped females using three-dimensional video analysis techniques. Mate-carrying female (CF) E. acutifrons spent significantly more time swimming at slower speeds than non-mate-carrying females (NCF). In addition, CFs did not attain the maximum swimming speeds attained by their NCF counterparts. Carrying females, however, displayed more complex swimming trajectories and were observed swimming in tight helical loops. We postulate that CFs were attempting to dislodge guarding males with this behaviour as a form of mate-guarding interference. Furthermore, given that mating pairs are more conspicuous and slower than non-mating individuals, we suggest that mate guarding is associated with increased predation risk.