Role of rotifers in microzooplankton community in a large monsoonal estuary (Cochin backwaters) along the west coast of India

Abstract

The distribution ecology of microzooplankton in the Kochi (Cochin) backwaters has been presented. Emphasis has been given to the micro-rotifers present in the environment, considering they were a hitherto ignored component of the microzooplankton in the past studies. Three seasonal samplings were carried out at six locations along the salinity gradients in the Kochi backwaters during the Pre-Monsoon (March), Southwest Monsoon (August), and Northeast Monsoon (December). A total of 48 species of microzooplankton were recorded, of which 35 were ciliates, 10 were rotifers, and 3 were heterotrophic dinoflagellates. The study also reports the swarm of a microzooplankton species from the Kochi backwaters, which was formed by a tintinnid ciliate, Tintinnopsis uruguayensis, during the Northeast Monsoon. Very high microzooplankton density (11,990 No. L), as swarm in the downstream location was associated with the mesohaline condition and high availability of food. Rotifers were the major component of microzooplankton in the limnohaline/oligohaline region, whereas ciliates dominated in the polyhaline/mesohaline region. Hence, in the present study, salinity appeared to be a major factor affecting the composition of the microzooplankton community in the Kochi backwaters. As rotifers have a wide food spectrum, they can feed on almost all components of the microbial food web, including small ciliates. They also share the same food spectrum with larger ciliates and crustacean nauplii. The present study, for the first time, recorded the importance of rotifers in the microzooplankton community in the plankton food web in the Kochi backwaters.

Effect of underground salty mine water on the rotifer communities in the Bolina River (Upper Silesia, Southern Poland)

“…Our results showed that in an urban river with underground saline mine water discharge (the Bolina River), the highest number of rotifer species was represented by the genus Brachionus. A similar relationship has been observed in naturally and anthropogenically saline rivers and water reservoirs (including estuaries and lakes) (Modenutti and Claps, 1988;Green, 1993;Neschuk et al, 2002;Arora and Mehra, 2009;Battauz et al, 2013;Anjusha et al, 2018). Similar to the Bolina River, Brachionus species not only dominated in the rotifer communities in the Bolina River but also in the Mossoró River Estuary (Medeiros et al, 2010) as well as in the saline lowland Salado River (Neschuk et al, 2002).…”

“…By contrast, the value of the Shannon-Wiener index for the rotifer communities of the most saline sections of the Vembanad estuary was higher. However, the value of the H 0 index for the rotifer communities of a large monsoonal estuary (Cochin backwaters) only ranged up to 1.7 (Anjusha et al, 2018).…”

Hypotoxic Fluorescent Nanoparticles Delivery by Cell-Penetrating Peptides in Multiple Organisms: From Prokaryotes to Mammalians Cells

“…They form the basis of the microzooplankton community in the plankton food web and link the energy flow to higher organisms. Recently, a growing number of studies considers rotifers as an indicator of marine pollution and toxicity of plastic nanoparticles [79][80][81], as well as a model species for pharmaceutical and toxicological studies [80,82]. To test the toxicity and uptake efficiency of fluorescent nanoparticles, Brachionus calyciflorus were treated with CdSe/ZnS QD red and IR9-FITC mixed CdSe/ZnS QD red complexes respectively (Figure 2).…”