Chemical cues from the invertebrate predator Leptodora kindtii affect the development of cyclomorphic traits in Eubosmina coregoni gibbera

The induction of two cyclomorphic traits, antennule length and carapace height, in Eubosmina coregoni gibbera by the cladoceran predator Leptodora kindtii was investigated in an experimental study. It was found that both carapace height and antennule length were significantly larger when the predator cues were present. However, antennule length only differed in adults, while juveniles showed no difference in antennule length between the treatments. Our results indicate that morphological anti-predator traits can reduce the vulnerability of adults, whereas the small size of juveniles may prevent the anti-predator traits from being effective.