Abundance, species composition of microzooplankton from the coastal waters of Port Blair, South Andaman Island

Abstract

BackgroundMicrozooplankton consisting of protists and metazoa <200 μm. It displays unique feeding mechanisms and behaviours that allow them to graze cells up to five times their own volume. They can grow at rates which equal or exceed prey growth and can serve as a viable food source for metazoans. Moreover, they are individually inconspicuous, their recognition as significant consumers of oceanic primary production. The microzooplankton can be the dominant consumers of phytoplankton production in both oligo- and eutrophic regions of the ocean and are capable of consuming >100% of primary production.ResultsThe microzooplankton of the South Andaman Sea were investigated during September 2011 to January 2012. A total of 44 species belong to 19 genera were recorded in this study. Tintinnids made larger contribution to the total abundance (34%) followed in order by dinoflagellates (24%), ciliates (20%) and copepod nauplii (18%). Foraminifera were numerically less (4%). Tintinnids were represented by 20 species belong to 13 genera, Heterotrophic dinoflagellates were represented by 17 species belong to 3 genera and Ciliates comprised 5 species belong to 3 genera. Eutintinus tineus, Tintinnopsis cylindrical, T. incertum, Protoperidinium divergens, Lomaniella oviformes, Strombidium minimum were the most prevalent microzooplankton. Standing stock of tintinnids ranged from 30–80 cells.L-1 and showed a reverse distribution with the distribution of chlorophyll a relatively higher species diversity and equitability was found in polluted harbour areas.ConclusionsThe change of environmental variability affects the species composition and abundance of microzooplankton varied spatially and temporarily. The observations clearly demonstrated that the harbor area differed considerably from other area in terms of species present and phytoplankton biomass. Further, the phytoplankton abundance is showed to be strongly influenced by tintinnid with respect to the relationship of prey–predator. Consequently, further investigation on microzooplankton grazing would shed light on food web dynamics.

Spatial variability of microzooplankton in the central Arabian Sea during spring intermonsoon

“…followed by an inability of MZP to graze on this larger phytoplankton. A similar observation was recorded during a diatom bloom in the East China Sea and Andaman Coastal waters (Elangovan et al, ; Lee & Kim, ). In earlier studies, the phytoplankton composition from the same region is well reported with the chain‐forming species such as Chaetoceros sp., Thalassiosira sp., Rhizosolenia sp., and Bacillaria sp.…”

Dinoflagellate Bloom Produced by Protoperidinium divergens Response to Ecological Parameters and Anthropogenic Influences in the Junglighat Bay of South Andaman Islands

“…Junglighat (92° 43'56"N and 11° 39'21"E) is a moderately polluted area found in the East Coast of Andaman [15] with a sewage influx in the centre of the area. Junglighat Bay is situated near Haddo harbour and is a major fish landing centre for Port Blair.…”

“…The triplicate surface water samples were collected in clean polyethylene bottles for analysis of nutrients, which were stored immediately in an ice box before transfer to the laboratory. The collected water samples were filtered by using a Millipore filtering system and then analyzed for dissolved inorganic nitrate, nitrite, reactive silicate and inorganic phosphate, adopting the standard procedures described by [15] and expressed in µmol L -1 . For the identification of species, 1 ml of sample were put on a Sedgwick rafter counter slide, covered with a cover glass and examined under light microscope.…”

Dynamics of extracellular superoxide production by Trichodesmium colonies from the Sargasso Sea

“…Despite the importance of superoxide to the growth and activity of Trichodesmium, the conditions promoting extracellular production are largely unknown and unexplored in oligotrophic environments. Further, Trichodesmium blooms oftentimes also contain high abundances of other plankton, including, for instance, the widespread diatom Coscinodiscus (Karthik et al 2012), that may contribute to ROS cycling within the bloom community. Accordingly, the goals of this study were to measure rates of superoxide production by natural Trichodesmium populations and associated diatoms obtained from various surface waters in the Sargasso Sea and to evaluate how these activities were modulated.…”