Zooplankton imaged with the In-situ Ichthyoplankton Imaging SystemDeep-Focus Particle Imager (ISIIS-DPI). The line-scan cameras on the ISIIS-DPI record shadows of organisms as they swim through the light of an LED. The resulting images, or shadowgraphs, are crisp, black and white silhouettes of water column organisms that look almost like line drawings.