Halophilic benthic diatom Amphora coffeaeformis—A potent biomarker for lipid and biomedical application

Biomarkers offer a powerful means to study life and its interaction with the environment. The evolutionary record of eukaryotic phytoplankton has been studied through fossils and molecular biomarkers, such as lipids and nucleic acids. Algal taxonomic groups containing carotenoids serve as age diagnostic biomarkers associated to photosynthetic pigments or fatty acids. Diatoms are known to thrive even in hypersaline conditions which are restricted to higher salinity. Results of this study have revealed the presence of a specific highly branched isoprenoid (HBI) compound, squalene (0.004 g) in the halophilic benthic diatom Amphora coffeaeformis which is considered to be the marker for hyper salinity. It also corresponds to the biomarker of oxidation processes.

Seasonal variations in physico-chemical characteristics of pond and ground water of Tiruchirapalli, India.

The aim of this study was to assess the open pond and groundwater quality of Tiruchirapalli city of Tamil Nadu, India. The groundwater quality viz., pH, electrical conductivity, total hardness, calcium ion, magnesium ion, chloride, carbonate, bicarbonate, inorganic nitrate, nitrite, phosphate, ammonia and reactive silicate were analysed with respect to various seasons and recorded in the range of 7.1 to 8.1, 97.67 to 533.67 mhos cm-1, 7.07 to 186 mg l-1, 4.67 and 112.0 mg l-1, 2.40 to 92.80 mg l-1, 15.23 to 661.73 mg l-1, 60 to 480 mg l-1, 22.7 to 544.9 mg l-1, 15.33 to 68.00 mg l-1, 0.001 to 0.480 mg l-1, 0.01 to 0.42 mg l-1, 0.02 to 0.75 mg l-1 and 1.1 to 2.96 mg l-1 respectively. The present findings concluded that the quality of ground waters can be considered suitable for human consumption. But the pond water available in and around Tiruchirappalli city was not fit for human usage, agricultural or industrial purposes.

Copepod population in Vellar estuary, Parangipettai coast in relation to environmental conditions.

Distribution and abundance of copepods were studied in relation to environmental conditions at two different ecosystems viz: Neritic (Bay of Bengal) and estuarine (Vellar estuary) of Parangipettai coast from September, 1998 to August, 2000. Over the study period, total 85 species of copepods were reported. Among these, the calanoid copepods constituted the major component with 63.52% followed by cyclopoids (29.41%) and harpacticoids (7.05%). The copepods population density was found to be high (2, 53, 000 org l-1) in estuarine water, while the species diversity was higher (5.47) in neritic water. The observed spatio-temporal variations in the population density and species diversity of copepods were more related to the environmental state of respective study area.