Summary of Abstract Submission

Abstract Submission No. IO50-09-0013PresentationPoster

SOME ASPECTS OF THE BLOOM FORMING PLANKTONIC CILIATE MESODINIUM RUBRUM (LOHMANN, 1908)

Biraja Kumar Sahu*1, P. Pati1, R. C. Panigrahy1

1 Department of Marine Sciences, Berhampur University, India

ABSTRACT :

Ciliates form an important group of microzooplankton in the marine environment. The mixotrophic mode of life cycle of some planktonic ciliates is now found playing major role in quantitative functioning of aquatic ecosystems. Some species of ciliate like Strombidium lingulum, S. reticulatum, Tiarina fusus, Cyclotrichium meunieri, Prorodon sp, Mesodinium sp emerged as blooming forms causing discolouration of surface waters to red or reddish brown. Most of these species have extraordinary ability of retaining plastids in their body and keeping them functional. It has been noticed that Mesodinium rubrum is capable of retaining the nuclei of its prey in their body and also keep them active. This ciliate is an obligate mixotroph that cannot grow in dark even when food supply is plenty. Thus it is considered functionally same as the autotrophic phytoplankton. It has been reported that this species could form non-toxic red-tides in coastal waters causing unprecedented high rates of primary production. This species is found closely linked with the harmful bloom forming dinoflagellate Dinophysis sp as an important prey of the dinoflagellate. Studies have further shown that M. rubrum blooms serve as biogeochemical hotspots being connected with increased dissolved organic matter and microbial secondary productions. This species received more attention for research after the discovery of its dependence on ingestion of cryptophyte algae and establishment of stable culture.