caa a22 4500 605455465 CHVBK 20210128100212.0 cr unu---uuuuu 210128e20150801xx s 000 0 eng 10.1007/s10872-015-0292-6 doi (NATIONALLICENCE)springer-10.1007/s10872-015-0292-6 Seasonal variations in abundance, biomass and grazing rates of microzooplankton in a tropical monsoonal estuary [Elektronische Daten] [Mangesh Gauns, Sunita Mochemadkar, Shrikant Patil, Anil Pratihary, S. Naqvi, M. Madhupratap] Seasonal abundance, composition and grazing rates of microzooplankton (20-200µm) in the Zuari estuary were investigated to evaluate their importance in food web dynamics of a tropical monsoonal estuary. Average abundances of microzooplankton (organisms × 104 l−1) during the three seasons were 0.44 (southwest monsoon), 1.13 (post-monsoon) and 0.96 (pre-monsoon). Protozoan (ciliates, heterotrophic dinoflagellates and sarcodines) accounted for most (96%) of the microzooplankton community, with micrometazoan (nauplii and copepodid stages of copepods, fish eggs, etc.). being far less abundant. Among protozoans, ciliates (loricates and aloricates) were most numerous (69% of the total microzooplankton). Statistically significant (p<0.001) co-variations of microzooplankton with other biological parameters such as chlorophyll a and bacterial biomass were observed. Salinity influenced microzooplankton distribution, with an optimum range of 15-20. Microzooplankton formed a large organic carbon pool, accounting for 24-40% of the total carbon in the living matter. Seasonally averaged microzooplankton biomasses were 22.3, 36.1 and 24.6mmol C m−3, respectively, during the southwest monsoon, post-monsoon and pre-monsoon periods, and were largely supported by non-living particulate carbon (detritus) particularly during the non-monsoon seasons. Experimental studies revealed significant microzooplankton grazing on phytoplankton standing stock, mainly (>60%) by the pico and nano fraction (<20µm) for most of the year. Phytoplankton growth rates (day−1) ranged between 0.69 and 1.24. Microzooplankton grazing was estimated to consume 30-82% of the phytoplankton standing stock, and 58-97% of the daily primary production. Results of the present study highlight the role of the microzooplankton as an important consumer of phytoplankton production. The Oceanographic Society of Japan and Springer Japan, 2015 Microzooplankton nationallicence Bacteria nationallicence Phytoplankton nationallicence Mesozooplankton nationallicence Food web nationallicence Zuari estuary nationallicence Gauns Mangesh CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut Mochemadkar Sunita Directorate of Fisheries, Govt. of Goa, Dayanand Bandokar Marg, Panaji, Goa, India aut Patil Shrikant Stazione Zoologica Anton Dohrn, Naples, Italy aut Pratihary Anil CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut Naqvi S. CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut Madhupratap M. CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut Journal of Oceanography Springer Japan 71/4(2015-08-01), 345-359 0916-8370 71:4<345 2015 71 10872 https://doi.org/10.1007/s10872-015-0292-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10872-015-0292-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gauns Mangesh CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut NATIONALLICENCE 700 1- Mochemadkar Sunita Directorate of Fisheries, Govt. of Goa, Dayanand Bandokar Marg, Panaji, Goa, India aut NATIONALLICENCE 700 1- Patil Shrikant Stazione Zoologica Anton Dohrn, Naples, Italy aut NATIONALLICENCE 700 1- Pratihary Anil CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut NATIONALLICENCE 700 1- Naqvi S. CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut NATIONALLICENCE 700 1- Madhupratap M. CSIR-National Institute of Oceanography, 403 004, Dona Paula, Goa, India aut NATIONALLICENCE 773 0- Journal of Oceanography Springer Japan 71/4(2015-08-01), 345-359 0916-8370 71:4<345 2015 71 10872