A. P. Sharma

Amino Acid Compositions of 27 Food Fishes and Their Importance in Clinical Nutrition

Proteins and amino acids are important biomolecules which regulate key metabolic pathways and serve as precursors for synthesis of biologically important substances; moreover, amino acids are building blocks of proteins. Fish is an important dietary source of quality animal proteins and amino acids and play important role in human nutrition. In the present investigation, crude protein content and amino acid compositions of important food fishes from different habitats have been studied. Crude protein content was determined by Kjeldahl method and amino acid composition was analyzed by high performance liquid chromatography and information on 27 food fishes was generated. The analysis showed that the cold water species are rich in lysine and aspartic acid, marine fishes in leucine, small indigenous fishes in histidine, and the carps and catfishes in glutamic acid and glycine. The enriched nutrition knowledge base would enhance the utility of fish as a source of quality animal proteins and amino acids and aid in their inclusion in dietary counseling and patient guidance for specific nutritional needs.

Ecological significance and phosphorus release potential of phosphate solubilizing bacteria in freshwater ecosystems

Phosphorus (P) is a limiting nutrient in some freshwater ecosystems. Phosphate solubilizing bacteria (PSB) are candidates for enhancing P availability in rhizoplane, but their P release potential in freshwater environments needs further evaluations. This study conducted in floodplain wetlands correlated PSB abundance, decline in sediment pH, and natural mobilization of sediment Ca–P. PSB were abundantly present in floodplain wetland waters, sediments, and in river and ponds, showing low to moderate Ca–P solubilization activity; PSB from Churni River and Bhomra wetland sediments had comparatively higher activity than those from other environments. In laboratory sediment microcosms, PSB were effective in enhancing available P concentration in interstitial water indicating their P release potential. However, P-fractionation of incubated sediments showed only a short-term decline in Ca–P by PSB, suggesting that Ca–P might not be their sole or preferred metabolic target. Despite low to moderate activity in culture medium, high population density and efficacy in P release in sediment suggest significant role of PSB in P cycling in freshwater environments.

Investigating hsp Gene Expression in Liver of Channa striatus under Heat Stress for Understanding the Upper Thermal Acclimation

Changes in hsp gene expression profiles in murrel Channa striatus experimentally exposed to temperature stress (36°C) for 4, 15, and 30 days were investigated; fish collected from aquaculture ponds and maintained in laboratory at the pond temperature (25 ± 1°C) served as control. Channa collected from a hot spring runoff (36°C) was included in the study to examine the hsp profiles beyond 30 days of exposure. Gene expression analyses of a battery of hsps in liver tissues were carried out by quantitative RT-PCR and protein expressions were analyzed by immunoblotting. hsps could be grouped into three clusters based on similarity in response to heat stress: hsp70, hsp78, and hsp60, whose transcript level continued to increase with duration of exposure; hsp90 and hsp110 that increased to a much higher level and then decreased; hsp27 and hsp47 that did not significantly vary as compared to control. The results suggest that Hsp70, Hsp78, and Hsp60 are involved in thermal acclimation and long term survival at high temperature. Fish living in the hot spring runoff appears to continuously express hsps that can be approximated by long term induction of hsps in farmed fish if temperature of their environment is raised to 36°C.

Climate Change: Impacts on Fisheries and Aquaculture

Climate change has been recognized as the foremost environmental problem of the twentyfirst century and has been a subject of considerable debate and controversy. It is predicted to lead to adverse, irreversible impacts on the earth and the ecosystem as a whole. Although it is difficult to connect specific weather events to climate change, increases in global temperature has been predicted to cause broader changes, including glacial retreat, arctic shrinkage and worldwide sea level rise. Climate change has been implicated in mass mortalities of several aquatic species including plants, fish, corals and mammals. The present chapter has been divided in to two parts; the first part discusses the causes and general concerns of global climate change and the second part deals, specifically, on the impacts of climate change on fisheries and aquaculture, possible mitigation options and development of suitable monitoring tools.

Lipid Biomarkers of Lens Aging

Lipids are important structural components of cell membranes and have profound effect on membrane fluidity. Lipid profiling and lipidomics have captured increased attention due to the well-recognized roles of lipids in numerous human diseases. Investigating lipid profiles not only provides insights into the specific roles of lipid molecular species in health and diseases, but can also help in identifying potential preventive or therapeutic biomarkers. Cataract, the loss of transparency of eye lens, is a disease of protein aggregation. There are several factors contributing to the stability in protein conformation. Age-related changes in lipid composition could be a contributing factor for altered protein–lipid interaction leading to protein aggregation and cataract. Keeping this in view, in the present study, fatty acid profiling from different age groups of lenses was carried out, using a freshwater catfish as the model. Total lipids were extracted from lenses of three different age groups of fishes (young, adult, and aged) and fatty acid methyl esters (FAME) were prepared and FAME analysis was carried out using gas chromatography–mass spectrometry. The results showed that three fatty acids viz. heneicosylic acid (C21), docosahexaenoic acid (C22:6), nervonic acid (C24:1) which were not present in the adult lens, appeared in the aged lens. On the other hand, eicosenoic acid (C20:1) present in the adult lens was found to be absent in the aged lens. The appearance or disappearance of these fatty acids can possibly serve as biomarkers of aging lens which is the most vulnerable stage for cataract development.

Ichthyofaunal diversity, assemblage structure and seasonal dynamics in the freshwater tidal stretch of Hooghly estuary along the Gangetic delta

The tidal freshwater areas of estuaries have received little attention in ecological research although they are often heavily stressed by environmental impacts. These critical habitats contribute significantly to the biodiversity of the entire estuarine system. The present study aims to describe the fish diversity, assemblage structure and seasonal dynamics through data collected by intensive sampling of the tidal freshwater stretch of the Hooghly estuary (June 2010 to June 2012), the largest estuary in India formed in the Gangetic delta. The tidal freshwater zone of Hooghly has gained importance due to ecological changes during the post-Farakka period since this zone covers 74% of the total estuarine stretch. During the study, a total of 155 fish species belonging to 49 families and 15 orders were recorded from the tidal freshwater zone of the Hooghly estuary. The exotic ornamental fish Barbonymus altus (Tinfoil Barb) has been recorded from the tidal freshwater zone which is the first record of these species in Indian inland waters. A detailed analysis of the fish diversity revealed that of the total 155 species recorded from the study, 19 species have been listed in category of threatened fishes by National Bureau of Fish Genetic Resources (Lakra et al., 2010). This includes 16 vulnerable (VU) species and 4 endangered (EN) species. This signifies the role of tidal freshwater zone as an essential fish habitat due to its rich fish diversity and as a sheltered area which favours the growth and survival of larval and juvenile fish assemblages.

Effect of storage temperature as a preanalytical variable on the lens crystallins protein quality for proteomic studies

Purpose: To study the effect of storage temperature on lens crystallins quality for proteomic analysis, using αA‐crystallins as internal marker.

Genetic stock structure of Osteobrama belangeri (Valenciennes, 1844) in Indian region

Abstract Osteobrama belangeri is an important medium carp endemic to Manipur state in India Myanmar and Yunnan Province of China. Although the species is listed as Near Threatened species according to IUCN status with sizeable population available in Myanmar, it is Extinct in the Wild in Manipur. An 842 bp segment ATP synthase 6/8 region of mtDNA was sequenced and analysed for 56 O. belangeri individuals. Analysis of population differentiation showed no significant genetic differentiation between the four sampling localities (ΦST = −0.034, p = 0.819). Results were further corroborated by a non-significant nearest neighbour statistics (Snn = 0.223, p = 0.897) and exact test of population differentiation (p = 0.893). Phylogeographic analysis revealed two haplogroups, but there was no obvious phylogeographic pattern separating the sampling localities. The present study suggests a single panmictic population of O. belangeri in Indian region.

Genetic differentiation in Indian Major Carp, Cirrhinus mrigala (Hamilton, 1822) from Indian Rivers, as revealed by direct sequencing analysis of mitochondrial Cytochrome b region

Abstract A 307 bp segment of Cytochrome b gene of mtDNA was sequenced and analyzed for 90 individuals of Cirrhinus mrigala collected across the three rivers, namely Ganges, Narmada and Brahmaputra. Analyses revealed the presence of 14 haplotypes with haplotype diversity (h) ranging from 0.304 to 0.692, and nucleotide diversity (π) 0.002–0.043. The majority of variation was found within the population (96.21%), and the FST value (0.035) as well as the value of exact test of population differentiation (0.893) were found to be insignificant (p < 0.05). Analysis of molecular variance (AMOVA) also indicated insignificant differentiation among sub-populations. Generally, low genetic differences were observed even though those populations were from different geographic locations. The present study suggests a single panmictic population of C. mrigala across the three rivers of India.

Arsenic in freshwater ecosystems of the Bengal delta: status, sources and seasonal variability

The study aimed to examine the contamination status of arsenic (As) in excavated small water bodies, commonly known as ponds – the integral part of daily life in the arsenic-affected rural areas of West Bengal, India in comparison to the unaffected areas. The ponds of the contaminated area had higher levels of As: water 2–174 µg L−1 (mean 31 ± 2 µg L−1) and sediment 1.3–37.3 mg kg−1 (mean 10.3 ± 0.4 mg kg−1), than those from the unaffected area: water 1–8 µg L−1 (mean 4 ± 0 µg L−1) and sediment 1.4–5.3 mg kg−1 (mean 3.0 ± 0.1 mg kg−1). A moderate positive correlation was observed between the water and sediment arsenic content of the ponds of the arsenic-affected region (r = 0.688, n = 277, p < 0.0001). Contaminated ground water, either as direct input or through agricultural washings, was found to be the major contributor of arsenic pollution to these ecosystems. Seasonal variations were not prominent. This study emphasized the beneficial role of using the studied ecosystems over the highly contaminated ground water for various livelihood activities in the Gangetic delta region.