The predator is an adult female Oithona plumifera (Copepoda, Cyclopoida) of near 600 µm prosome length and the prey a protozoon Strobilidium sp. (Ciliata) of 40 µm width. The genus Oithona is an ambush predator which only occasionally relocates i.e. almost always is motionless waiting for motile prey. The predator uses the numerous setae positioned in 3-D on its first antennae (A1, length 1 mm) to locate the oncoming prey and to monitor its path as it approaches the predator. The setae on the A1 range in length from about 300 to 500 µm. As the prey moves at about 5 mm s-1 the predator knows what to do: The copepod waits until the ciliate is in close vicinity of its head appendages and then, with a sudden leap at a velocity of 58 mm s-1, captures the ciliate with its extended head appendages. This capture process is too fast to be recorded at 60 frames s-1. The event shown here is shown at 50% of the actual velocities.
SkIO :
This event is among the many described in a paper by Jiang, H. and G.-A. Paffenhöfer (2008) Hydrodynamic signal perception by the copepod Oithona plumifera. Mar Ecol Prog Ser 373:37-52.
