Acknowledgements
We gratefully acknowledge the crew and pilots of the R/V Western Flyer and ROV Doc Ricketts, R/V Rachel Carson andROV Ventana for their help with collecting these delicate specimens and assistance with blue-water diving. We would like to thank Warren Francis for generating many of our transcriptome data and for providing helpful comments on the manuscript. April Woods and Maile Prickett were instrumental in PCR and sequencing help, and we thank Kyra Schlining and Susan Von Thun for support at sea. We would also like to thank Jacob Winnikoff who created some of the silhouettes for figure 2, helped collect specimens, and for his constructive comments on the manuscript. Numerous specimens were donated by Bruce Robison, Rob Sherlock, Kristine Walz, David Clague, Lonny Lundsten, William Browne, Stacy Kim, Keith Bayha, Larry Madin, Wyatt Patry (Monterey Bay Aquarium), California Academy of the Sciences, and Ocean Genome Legacy Center to increase our sampling breadth. We also graciously acknowledge Katie Pitz, who provided ctenophore sequences from her metabarcoding library. This work was funded by the David and Lucile Packard Foundation, the National Science Foundation (NSF-DEB 1542679 to SHDH) and the National Institutes of Health (R01-GM087198).