STUDY ON ICHTHYOFAUNAL DIVERSITY IN RELATION TO PHYSICO-CHEMICAL PARAMETERS OF MANAKONDUR FRESH WATER LAKE OF KARIMNAGAR DISTRICT, TELANGANA STATE, INDIA

Freshwater bodies are one of the most common and stable habitats of biosphere. The freshwater habitats have their own physico-chemical and biological characters which are subjected to modify by local conditions and physiographic features. The water quality parameters have a great influence on the growth and other factors of aquatic organisms. Therefore, the lentic water body gives a good source for fisheries. The present investigation deals with limnological and physico-chemical parameters and their influence on Ichthyofauna abundance in Manakondur fresh water Lake at Karimnagar District, Telangana State. The study was carried out for a period of one year i.e., from June, 2020 to May, 2021.The investigation was focused on the determination of hydro-chemical parameters such as Water temperature(19.0-31.0ºC),Transparency(18.50-44.30cm),TDS(200-350mg/l),PH(7.5-8.3),DO(5.2-12.0mg/l),Co2 (3.0-9.2mg/l),TH(110-210mg/l),TA(165-300mg/l),CL(35.00-50.20mg/l),Po4 (0.02-0.16mg/l),No3 (0.02-0.14mg/l) and BOD(2.5-7.0mg/l).The study was made to recorded fish fauna available. Total 33 species of fishes were collected and identified during the study period which belongs to 6 orders, 12 families and 18 genera. The order Cypriniformes was dominant with 15 species, followed by Siluriformes (8 species), Osteoglosiformes(2 species), Perciformes(4 species), Channiformes(3 species), Perciformes(4 species) and Antherniformes(1 species) were identified. Order wise percentage composition is Cypriniformes (17%), Siluroformes (34%), (Osteoglossiformes(8%), Perciformes (25%), Channiformes (8%), Anthrniformes (8%) In the light of recent literature, the data has been discussed and it is concluded that limnological and physico-chemical parameters in this reservoir are most comply with suitability of human consumption and favourable for fishery. In the light of recent literature, the data has been discussed and it is concluded that limnological and physico-chemical parameters in this reservoir are most comply with suitability of human consumption and favourable for fishery.

Climate Sadness: The Fragile Beauty of Tonlé Sap

Tonlé Sap is the large fresh water lake-river near the geographic center of Cambodia. Visiting Tonlé Sap, following an academic conference in Phnom Penh, demanded a response at a personal and more visceral human level. Writing this poem attempted to express disquiet beyond academic examination of the biophysical dimensions of Tonlé Sap. The poem is sad for Tonlé Sap, for Cambodia, and implicitly for all of us on this planet. For thousands of years people have lived around Tonlé Sap, adapting to weather, the flow of water from mountain to sea, and the changing ebb and flow of civilizations. Anthropogenic sea level rise challenges all of this human history, unnecessarily.

Absence of Surface Water Temperature Trends in Lake Kinneret despite Present Atmospheric Warming: Comparisons with Dead Sea Trends

This study was carried out using Moderate Resolution Imaging Spectroradiometer (MODIS) 1 km × 1 km resolution records on board Terra and Aqua satellites and in-situ measurements during the period (2003–2019). In spite of the presence of increasing atmospheric warming, in summer when evaporation is maximal, in fresh-water Lake Kinneret, satellite data revealed the absence of surface water temperature (SWT) trends. The absence of SWT trends in the presence of increasing atmospheric warming is an indication of the influence of increasing evaporation on SWT trends. The increasing water cooling, due to the above-mentioned increasing evaporation, compensated for increasing heating of surface water by regional atmospheric warming, resulting in the absence of SWT trends. In contrast to fresh-water Lake Kinneret, in the hypersaline Dead Sea, located ~100 km apart, MODIS records showed an increasing trend of 0.8 °C decade−1 in summer SWT during the same study period. The presence of increasing SWT trends in the presence of increasing atmospheric warming is an indication of the absence of steadily increasing evaporation in the Dead Sea. This is supported by a constant drop in Dead Sea water level at the rate of ~1 m/year from year to year during the last 25-year period (1995–2020). In summer, in contrast to satellite measurements, in-situ measurements of near-surface water temperature in Lake Kinneret showed an increasing trend of 0.7 °C decade−1.

The expansion of Acheulean hominins into the Nefud Desert of Arabia

The Arabian Peninsula is a critical geographic landmass situated between Africa and the rest of Eurasia. Climatic shifts across the Pleistocene periodically produced wetter conditions in Arabia, dramatically altering the spatial distribution of hominins both within and between continents. This is particularly true of Acheulean hominins, who appear to have been more tethered to water sources than Middle Palaeolithic hominins. However, until recently, chrono-cultural knowledge of the Acheulean of Arabia has been limited to one dated site, which indicated a hominin presence in Marine Isotope Stages (MIS) 7–6. Here, we report the first dated Acheulean site from the Nefud Desert of northern Saudi Arabia, together with palaeoecological evidence for an associated deep, probably fresh-water, lake. The site of An Nasim features varied and often finely flaked façonnage handaxes. Luminescence ages together with geomorphological and palaeoecological evidence indicates that the associated artefacts date to MIS 9. At present, An Nasim represents the oldest yet documented Acheulean sites in Arabia, and adds to a growing picture of regionally diverse stone tool assemblages used by Middle Pleistocene hominins, and likely indicative of repeated population re-entry into the peninsula in wet ‘Green Arabia’ phases.

Metagenomic analysis exploring taxonomic and functional diversity of bacterial communities of a Himalayan urban fresh water lake

Freshwater lakes present an ecological border between humans and a variety of host organisms. The present study was designed to evaluate the microbiota composition and distribution in Dal Lake at Srinagar, India. The non-chimeric sequence reads were classified taxonomically into 49 phyla, 114 classes, 185 orders, 244 families and 384 genera. Proteobacteria was found to be the most abundant bacterial phylum in all the four samples. The highest number of observed species was found to be 3097 in sample taken from least populated area during summer (LPS) whereas the summer sample from highly populated area (HPS) was found most diverse among all as indicated by taxonomic diversity analysis. The QIIME output files were used for PICRUSt analysis to assign functional attributes. The samples exhibited a significant difference in their microbial community composition and structure. Comparative analysis of functional pathways indicated that the anthropogenic activities in populated areas and higher summer temperature, both decrease functional potential of the Lake microbiota. This is probably the first study to demonstrate the comparative taxonomic diversity and functional composition of an urban freshwater lake amid its highly populated and least populated areas during two extreme seasons (winter and summer).