April 2, 2013
Copepod Nauplius Swimming at 10 Degrees C
High speed digital holography reveals the swimming stroke of a larva or “nauplius” of the copepod Acartia tonsa swimming in 10 degree C water. In cooler water conditions where the water is more viscous, movement is more difficult and nauplii propel themselves forward with longer power strokes so more time is spent moving forward. This pattern results in some backward motion during the stroke cycle (recovery phase) but the net result allows the nauplii to move further and faster than if they kept the same stroke motion used at 30 degree C. To get a feel for how fast copepods move, these clips were taken with high speed video at 3000 frames per second, and are played back at 100 frames per second in the clips, so these are slow motion at 1/30 speed.
Credit: Ed Buskey, Brad Gemmell and Jian Sheng