Environmental Factors and Genetic Diversity as Drivers of Early Gonadal Maturation: A Gonadosomatic Index Based Investigation on Indian Shad, Tenualosa ilisha Population of Bangladesh

In recent years, attaining gonadal maturation in smaller Hilsa (Tenualosa ilisha) has become a burning issue for Hilsa fishery of Bangladesh. Causes of early maturation are not yet clearly understood. Along with environmental parameters, genetic differentiation within the population was hypothesized as the main driver, and therefore, assessing the correlation between gonadosomatic index (GSI) and environmental factors and analyzing genetic diversity were set as objectives of the present study. To address these complex issues, six diverse habitats across Bangladesh were chosen for Hilsa sample collection. For GSI, gonad was dissected from fresh fish and preserved in Bouin’s fluid for histological observation. Water quality parameters such as temperature, dissolved oxygen, pH, and salinity were also assessed. 35 fish from each habitat were used to extract and amplify DNA through the PCR technique, and genetic diversity was examined. Further, to draw a firm conclusion, the phylogenetic tree of the Hilsa population was developed by the unweighted pair-group method of arithmetic mean method based on the Cyt b gene of mitochondrial DNA. Results of GSI studies revealed that peak spawning months of T. ilisha were in October and February, where October showed the highest values in all six habitats. Histological examination showed different stages of gonadal development in different sizes and ages of Hilsa. Among all sampling sites, no statistical difference was observed for GSI value; however, smaller sized and aged Hilsa being ripped were evident in Gaglajur Haor and Kali River. Among the observed water quality parameters, temperature correlated with GSI strongly. Increased GSI was observed with temperature augmentation from downstream to upper stream, irrespective of body size and age. A perplex correlation between dissolved oxygen of observed habitats and GSI was executed. Other physico-chemical parameters viz. pH and salinity exhibited weak and moderate positive association with the GSI, respectively. Haplotype diversity of mitochondrial DNA divided the Hilsa population into three possible sub-populations, where the most distant group (Gaglajur Haor and Kali River) was subjected to early gonadal maturity. Results of this study make clear conclusions regarding the role of environmental and genetic factors on early gonadal maturations, pointing fingers at the curse of climate change and anthropogenic stressors for the migration of the Hilsa fishery of Bangladesh.

Ecological studies on the aquatic macro-invertebrate population dynamics of the snow-fed Kali River in Uttarakhand, India

Freshwater macro-invertebrates are the bottom dwelling organisms. Their presence, distribution and diversity is affected by many eco-biological factors. The aim of this study was to assess the factors that impact upon the population dynamics of macro- invertebrates, while correlating the relationship between various physio-chemical parameters and macro-invertebrates from the Kali River, Pithoragarh (Uttarakhand). The samples were collected using a quartet square in the sampling area of one square feet of the stream bed, which was then, after placing in 70% alcohol, taken to the laboratory for identification and enumeration. A total of 24 genera and 28 species were found during the study, which belongs to 3 phylum, 5 classes, 10 order and 20 families. A total of eight physiochemical parameters were studied on a monthly basis round the year. The ecological impact was measured by establishing the correlation between recorded physio-chemical parameters and invertebrates’ diversity, in which water temperature, air temperature, velocity, and conductivity showed a negative correlation while pH, DO, total alkalinity, and total hardness showed a positive correlation. Various alpha diversity indices were estimated with the help of PAST software which indicated diverse macro-invertebrate communities in the Kali River in District Pithoragarh.

A Potential Bioactive Secondary Metabolites and Antimicrobial Efficacy of Streptomyces thermocarboxydus Strain KSA-2, Isolated from Kali River, Karwar

In the present study, an Actinomycetes strain KSA-2 was isolated from freshwater sediment samples of Kali River, Karwar, Karnataka, India. The strain KSA-2 was selected among seven isolates based on primary screening of antimicrobial activity against pathogenic organisms. The morphological physiological and biochemical characterizations were performed, the bioactive secondary metabolites were produced in liquid broth culture and was characterized by UV-Vis. spectroscopy and FTIR spectroscopy. Later, the potent KSA-2 strain was identified by 16S rRNA gene sequencing (1366 bp) and a phylogenetic tree was constructed and the strain KSA-2 was confirmed as Streptomyces thermocarboxydus strain KSA-2. Further, the characterization of methanolic extract by UV-Vis. and FTIR spectroscopy analysis revealed the presence of broad spectrum of antimicrobial and other compounds and alkyl halides, alkenes, sulfoxide, carboxylic acids, alkanes respectively.

Geographies of India-Nepal contestation

The commentary looks at how physiography and cartography can explain the ensuing tiff between India and Nepal. These geographies when deconstructed through critical cartography and critical hydropolitics present us with a new vantage point. The Kali River that marks the boundary between India and Nepal when reading through critical hydropolitics provides us with a new angle of vision. Secondly, we read the maps and story behind them to unearth the historico-political meanings. Thereby, reflecting on how India’s cartographic censorship is contested with counter-mapping by Nepal. Lastly, the cartographic rhetoric is uncovered that circulates in Nepal and the meanings and implications it holds for the relation between the two countries. The rhetoric has a broader vision through conceptualisation of space based on history. The paper contributes to understanding the existing geographies of contestation while providing ways for its resolution in the coming times.

North-Western Boundary of Nepal

Following the publication of new political maps by India on 2nd and 8th November 2019, the issues related to the source of Mahakali River and Indian occupation of the Nepali territory east of the river, have, once again, come to the surface. And, the Nepali civil society has come out strongly against the newly published political maps of India, prepared a new map of Nepal, showing the whole of the territory east of Mahakali River (about 400 sq. km) as Nepalese land on the basis of Treaty of Sugauli signed in 1816 by East India Company of Great Britain and Raja of Nepal. An analysis of the maps, so far available, shows that changes have been made in the names of the river and places, and there is cartographic aggression and manipulation by India in relation to Mahakali River and its boundary with Nepal’s northwest. It has also been found that Nepal has published a map in the past showing its international boundary without any basis of the treaties and other historical documents. Analysis clearly shows that the river originating from Limpiyadhura is the Mahakali (called Kalee/Kali River) as per Article 5 of the Sugauli treaty and it forms the international boundary between the two countries.