Mixotrophic scrippsielloid dinoflagellates prey on tintinnid ciliates

Abstract

Dinoflagellates can serve as predators or parasites of tintinnid ciliates. Known predators feed on the ciliate from outside the tintinnid lorica, while parasites either grow in the host cytoplasm or feed inside in the lorica while attached to the outside of the host cell. Here we report mixotrophic species of Scrippsiella that enter the lorica to consume the ciliate zooid of Helicostomella subulata from Denmark and multiple tintinnid species from Korea. We contrast morphology and life-history stages of these mixotrophic predators with dinokaryote parasites of tintinnids and address phylogenetic relationships based on rDNA sequences. Mixotrophic Scrippsiella species sometimes attack tintinnids that are simultaneously infected by syndinean dinoflagellates, complicating study of life histories and potentially leading to confusion about trophic status and taxonomy.

Keywords:

• dinokaryote
• parasite
• predator
• phylogeny
• Scrippsiella
• syndinean

Additional information

Funding

Research in Denmark supported in part by a 2011 international Ph.D. course sponsored by the Faculty of Science, University of Copenhagen Helsingør, Denmark. Travel costs for Y. Lu provided by the PACES research program, Alfred-Wegener-Institute Helmholtz-Zentrum für Polar- und Meeresforschung. Korea work supported by the Basic Core Technology Development Program for the Oceans and the Polar Regions of the National Research Foundation (NRF), with funding from the Ministry of Science, ICT and Future Planning, Republic of Korea (grant number NRF2016M1A5A1027456).