Asha Ravi - Academia.edu (original) (raw)

Papers by Asha Ravi

Regional Studies in Marine Science, Feb 1, 2021

Abstract Rotifers, because of their small size, slow motility, and high calorific value forms an ... more Abstract Rotifers, because of their small size, slow motility, and high calorific value forms an important live feed in aquaculture. The present study was conducted to elucidate the impact of the massive flood that occurred in Kerala during August 2018 on the estuarine hydrography and rotifer community of Cochin estuary, the largest tropical monsoonal estuary along the southwest coast of India. Sampling conducted in seven stations from the inlets to the upstream during the pre-flood, flood, and post-flood periods revealed conspicuous changes in the zooplankton community of the estuary, especially the rotifers. The decline in the rotifer abundance from pre-flood (17.6 ± 26.3 ind 100 m−3) to flood (1.3 ± 2.6 ind 100 m−3) followed by a sharp increase in the post-flood period (86 ± 129.8 ind 100 m−3) indicated the impact of the flood on the rotifer population. A conspicuous change was also noticed in their community structure with the genus, Keratella dominating during the low saline, pre-flood, and flood periods and the genus, Brachionus and specifically the species, Brachionus plicatilis dominating during the relatively high saline post- flood period. The species, Filinia longiseta var. acaudata (Filinia saltator, (Gosse, 1886), hitherto not recorded from the study area, was observed exclusively after the flood. Cochin estuary, being a monsoonal estuary where the high freshwater discharges associated with monsoon results in the washing out of a majority of the rotifer population, this scenario was much more aggravated by the massive flood that occurred during August 2018. However, with the reduction in the floodwater discharges, the concomitant increase noticed in the rotifer abundance indicates their rapid adaptation and proliferation strategies towards favourable hydrographic conditions in the estuary.

Journal of the Marine Biological Association of India, Sep 10, 2020

Zooplankton samples collected from six stations, along the Kollam-Kottappuram waterway (National ... more Zooplankton samples collected from six stations, along the Kollam-Kottappuram waterway (National Waterway 3) on the northern part of Lake Vembanad on monthly intervals during October 2018 to September 2019 formed the basis of this study. The samples were analysed both qualitatively and quantitatively by adopting standard methods. 23 groups of zooplankton were recorded from the study area. Out of these, a maximum of 18 groups were recorded from station 1 (Cochin bar mouth) and a minimum of 9 groups from station 6 (Kottappuram). Overall average density of zooplankton in the study area was 3044 numbers per 100 m 3. Station-wise studies indicated that the average zooplankton density was maximum (4882 per 100 m 3) at station 2 (Kadamakudy) and minimum (1649 per 100 m 3) at station 5 (Azhikode bar mouth). Among the different groups of zooplankton in the study area, a maximum of 79% was contributed by copepods, 14% by rotifers while the remaining groups contributed less than 2% each. Month-wise analysis indicated the maximum density during September and the minimum during January. Biodiversity analyses were carried out by Primer v. 6 software. From the cluster analysis and Bray-Curtis similarity matrix, July and August months showed the maximum similarity of species composition compared to all other months.

ICAR-Central Marine Fisheries Research Institute eBooks, 2018

मैंग्रोव पर्यावरण प्रणाली : भारत में एक निराशाजनक संसाध

Journal of the Marine Biological Association of India, 2020

Zooplankton samples collected from six stations, along the Kollam Kottappuram waterway (National ... more Zooplankton samples collected from six stations, along the Kollam Kottappuram waterway (National Waterway 3) on the northern part of Lake Vembanad on monthly intervals during October 2018 to September 2019 formed the basis of this study. The samples were analysed both qualitatively and quantitatively by adopting standard methods. 23 groups of zooplankton were recorded from the study area. Out of these, a maximum of 18 groups were recorded from station 1 (Cochin bar mouth) and a minimum of 9 groups from station 6 (Kottappuram). Overall average density of zooplankton in the study area was 3044 numbers per 100 m3 . Station-wise studies indicated that the average zooplankton density was maximum (4882 per 100 m3 ) at station 2 (Kadamakudy) and minimum (1649 per 100 m3 ) at station 5 (Azhikode bar mouth). Among the different groups of zooplankton in the study area, a maximum of 79% was contributed by copepods, 14% by rotifers while the remaining groups contributed less than 2% each. Month...

Regional Studies in Marine Science, 2021

Rotifers, because of their small size, slow motility, and high calorific value forms an important... more Rotifers, because of their small size, slow motility, and high calorific value forms an important live feed in aquaculture. The present study was conducted to elucidate the impact of the massive flood that occurred in Kerala during August 2018 on the estuarine hydrography and rotifer community of Cochin estuary, the largest tropical monsoonal estuary along the southwest coast of India. Sampling conducted in seven stations from the inlets to the upstream during the pre-flood, flood, and post-flood periods revealed conspicuous changes in the zooplankton community of the estuary, especially the rotifers. The decline in the rotifer abundance from pre-flood (17.6 ± 26.3 ind 100 m−3) to flood (1.3 ± 2.6 ind 100 m−3) followed by a sharp increase in the post-flood period (86 ± 129.8 ind 100 m−3) indicated the impact of the flood on the rotifer population. A conspicuous change was also noticed in their community structure with the genus, Keratella dominating during the low saline, pre-flood,...