Report of Apogonichthyoides sialis (Perciformes: Apogonidae) from the west coast of India

The cardinal fish, Apogonichthyoides sialis, previously known from the eastern Indian Ocean and western Pacific, is reported from the south-west coast of India (Kerala coast). The specimens are described and figured

Planktonic food web structure at SSTF and PF in the Indian sector of the Southern Ocean during austral summer 2011

This study aims to describe the planktonic food web structure with respect to phytoplankton biomass (chlorophyll a ) and prevailing environmental conditions at the South Subtropical Front (SSTF) and the Polar Front (PF) in the Indian sector of the Southern Ocean. Sampling was carried out at each front for 72 hrs, at 6-hr intervals, during the austral summer 2011. Considerable variations were observed in the hydrography between these two fronts. A strong temperature minimum layer was observed at the PF. Although the surface primary production and chlorophyll a values showed similar trends at both the fronts, the water column values of these parameters showed major disparities. The phytoplankton composition also revealed marked difference between the fronts. A deep chlorophyll maximum concordant with the upper limit of the temperature minimum layer was prominent at the PF. The microzooplankton abundance at the SSTF was twice as high as at the PF. The mesozooplankton biovolume and population density also showed considerable variations between these fronts. Noticeable diel variations were observed in the surface mesozooplankton biovolumes at both the fronts and the copepod Pleuromamma gracilis showed active diel vertical migration at SSTF. Both the grazing and senescence indices showed significant variations between these fronts, suggesting a disparity in the ecological efficiency of the two regions. The variability observed in the plankton community structure with respect to the hydrography and the biological components measured suggests that a multivorous food web at the SSTF and a conventional food web at the PF prevailed during the period of study

Planktonic food web structure at SSTF and PF in the Indian sector of the Southern Ocean during austral summer 2011

This study aims to describe the planktonic food web structure with respect to phytoplankton biomass (chlorophyll a) and prevailing environmental conditions at the South Subtropical Front (SSTF) and the Polar Front (PF) in the Indian sector of the Southern Ocean. Sampling was carried out at each front for 72 hrs, at 6-hr intervals, during the austral summer 2011. Considerable variations were observed in the hydrography between these two fronts. A strong temperature minimum layer was observed at the PF. Although the surface primary production and chlorophyll a values showed similar trends at both the fronts, the water column values of these parameters showed major disparities. The phytoplankton composition also revealed marked difference between the fronts. A deep chlorophyll maximum concordant with the upper limit of the temperature minimum layer was prominent at the PF. The microzooplankton abundance at the SSTF was twice as high as at the PF. The mesozooplankton biovolume and population density also showed considerable variations between these fronts. Noticeable diel variations were observed in the surface mesozooplankton biovolumes at both the fronts and the copepod Pleuromamma gracilis showed active diel vertical migration at SSTF. Both the grazing and senescence indices showed significant variations between these fronts, suggesting a disparity in the ecological efficiency of the two regions. The variability observed in the plankton community structure with respect to the hydrography and the biological components measured suggests that a multivorous food web at the SSTF and a conventional food web at the PF prevailed during the period of study

Relative vulnerability assessment of Indian marine fishes to climate change using impact and adaptation attributes

Not AvailableFish is a poikilothermic animal that cannot regulate body temperature through physiological process; this is regulated instead by environmental process. Fish physiology, like growth and reproduction is directly influenced by changes in temperature. With rising environmental temperature, the physiological activities of fishes also increase, which in turn increases the oxygen demand. But the solubility of oxygen in water is inversely related to temperature and salinity (Weiss, 1970). Thus, dissolved oxygen availability in water will decrease, resulting in the reduction of growth and reproduction success of fishes and prevent them from dealing as effectively with other environmental changes. This is particularly true in the case of fishes living in closed water bodies. In an open ocean system, several factors play a synergistic role in impacting the physiology of the organisms.Not Availabl

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