Experimental and modeling evidence of appendicularian-ciliate interactions

Fabien Lombard, D. Eloire, A. Gobet, L. Stemmann, J. Dolan, G. Gorsky

Research output: Contribution to conferenceConference abstract for conferenceResearch

Abstract

Interactions between appendicularians and ciliates were observed over the life span of Oikopleura dioica in laboratory cultures and clarified with the use of mathematical modeling and microscopic observations. Complex interactions including competition, parasitism, predation, and histophagy occurred simultaneously, resulting in apparent mutualism. The large ciliate Strombidium sp. entered the inlet filters of appendicularian houses (larger than 500 µm body size) by distorting the mesh. Once inside, Strombidium fed on particles concentrated on the filters. When appendicularians were larger than 900 µm, both the high flow rate in the buccal tube and their esophagus width allowed the "host" appendicularian to capture and ingest ciliates. Thus, ciliates seem to be sequentially competitors, then parasites or commensal in appendicularian houses, and finally prey for appendicularians. Appendicularian rates of somatic growth and reproduction were enhanced when ciliates were ingested. This additional food supply could be essential in oligotrophic environments. Reciprocally, appendicularians support higher ciliate growth rates, allowing ciliates to survive and grow in food-limited environments. Appendicularians thus modify the size spectrum of the microbial food web both by removing small organisms (0.2–30 µm) and enhancing the growth of mid-sized and large ciliates.
Original languageEnglish
Publication date2010
Publication statusPublished - 2010
Event2010 ASLO Ocean Sciences Meeting: From Observation to Prediction in the 21st Century - Portland, OR, United States
Duration: 22 Feb 201026 Feb 2010
http://www.agu.org/meetings/os10/

Conference

Conference2010 ASLO Ocean Sciences Meeting
CountryUnited States
CityPortland, OR
Period22/02/201026/02/2010
Internet address

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