Graphite Chaetognaths or arrow worms are predatory zooplankton that eat copepods and other smaller zooplankton and also fish larvae. They are large enough to be seen by the naked eye, but they are still very small and very transparent. I got to actually see live copepods and chaetognaths in the microscope thanks to biologist Carin Ashjian! Leave a Reply Cancel Reply Your email address will not be published. Name* Email* Website Comment Notify me of follow-up comments by email. Notify me of new posts by email.