Debajit Sarma

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.

DHA and EPA Content and Fatty Acid Profile of 39 Food Fishes from India

Docosahexaenoic acid (DHA) is the principal constituent of a variety of cells especially the brain neurons and retinal cells and plays important role in fetal brain development, development of motor skills, and visual acuity in infants, lipid metabolism, and cognitive support and along with eicosapentaenoic acid (EPA) it plays important role in preventing atherosclerosis, dementia, rheumatoid arthritis, Alzheimers disease, and so forth. Being an essential nutrient, it is to be obtained through diet and therefore searching for affordable sources of these ω-3 polyunsaturated fatty acids (PUFA) is important for consumer guidance and dietary counseling. Fish is an important source of PUFA and has unique advantage that there are many food fish species available and consumers have a wide choice owing to availability and affordability. The Indian subcontinent harbors a rich fish biodiversity which markedly varies in their nutrient composition. Here we report the DHA and EPA content and fatty acid profile of 39 important food fishes (including finfishes, shellfishes, and edible molluscs from both marine water and freshwater) from India. The study showed that fishes Tenualosa ilisha, Sardinella longiceps, Nemipterus japonicus, and Anabas testudineus are rich sources of DHA and EPA. Promotion of these species as DHA rich species would enhance their utility in public health nutrition.

Micronutrient Composition of 35 Food Fishes from India and Their Significance in Human Nutrition

The micronutrients (vitamins and minerals) are required in small amounts but are essential for health, development, and growth. Micronutrient deficiencies, which affect over two billion people around the globe, are the leading cause of many ailments including mental retardation, preventable blindness, and death during childbirth. Fish is an important dietary source of micronutrients and plays important role in human nutrition. In the present investigation, micronutrient composition of 35 food fishes (includes both finfishes and shellfishes) was investigated from varying aquatic habitats. Macrominerals (Na, K, Ca, Mg) and trace elements (Fe, Cu, Zn, Mn, Se) were determined by either atomic absorption spectroscopy (AAS) or inductively coupled plasma mass spectrometry (ICP-MS)/atomic emission spectrometry (ICP-AES). Phosphorus content was determined either spectrophotometrically or by ICP-AES. Fat-soluble vitamins (A, D, E, K) were analyzed by high-performance liquid chromatography (HPLC). The analysis showed that, in general, the marine fishes were rich in sodium and potassium; small indigenous fishes (SIFs) in calcium, iron, and manganese; coldwater fishes in selenium; and the brackishwater fishes in phosphorous. The marine fishes Sardinella longiceps and Epinephelus spp. and the SIFs were rich in all fat-soluble vitamins. All these recommendations were made according to the potential contribution (daily value %) of the species to the recommended daily allowance (RDA). Information on the micronutrients generated would enhance the utility of fish in both community and clinical nutrition.

Morpho‐histological and ultra architectural changes during early development of endangered golden mahseer Tor putitora

Ultrastructural and histological changes in the embryonic and larval surface during ontogenesis of the endangered golden mahseer Tor putitora is studied here for the first time. Embryonic development was completed 91-92 h after fertilization at an ambient temperature of 23° ± 1° C (mean ± s.d.). The gastrula stage was characterized by presence of the Kupffers vesicle, notochord, ectoderm and endoderm cells. Primordial germ cells were clearly identifiable from c. 55 h post-fertilization at the organogenesis stage. Mean total length of newly hatched larvae was 7·0 ± 0·5 mm. Scanning electron microscopy of newly hatched larvae demonstrated vitelline arteries, microridged epithelial cells and mucous gland openings over much of the body surface. Eye, oral cavity, pharyngeal arches, heart, intestinal loop, prosencephalon, cephalic vesicle and nasal epithelium were clearly distinguished in 3 day old hatched individuals. In 6 day old individuals, caudal-fin rays and internal organs were evident. The dorsal fin became prominent at this stage and larvae began swimming at the surface. The reserved yolk material was totally absorbed 8-11 days after hatching and larvae began feeding exogenously. Tor putitora exhibited a longer early developmental period than other cyprinids reared at similar temperatures.

Proximate and mineral composition of some selected coldwater fishes of upland Himalaya

Purpose – The present study aims to determine the proximate and mineral composition of important coldwater food fishes in the North Eastern Indian upland region to assess their nutritional quality. Design/methodology/approach – The paper is of original work and the analyses were performed using AOAC (1990). Data were analyzed by one-way analysis of variance (ANOVA) and determined by Duncan’s Multiple Range Test using SPSS (Version 19). Findings – Crude protein levels ranged from 16-20 per cent, crude fat (CF) 9.60-1.54 per cent and ash 3.5-0.99 per cent. Moisture content was in the range of 71-78 per cent. The lowest moisture content was observed in Semiplotus semiplotus and highest in Labeo dero. Sodium, potassium and calcium content ranged from 92-309, 692-1435, 467-2021 mg/100g, respectively. Maximum concentration of potassium was found in Labeo dero followed by Labeo pangusia. Selenium was most abundant in L. dero, Labeo dyocheilus, Sanguina sanguine, Barilius bendelisis, Garra mullya, L. pangusia and...

The microcystins-induced DNA damage in the liver and the heart of zebrafish, Danio rerio

Microcystins (MCYST) are the freshwater cyanobacterial toxins, known to induce hepatocellular carcinoma, necrosis, intrahepatic bleeding, as well as human and livestock mortality. Within hepatocytes, MCYST selectively bind to protein phosphatases 1 and 2A, resulting in severe liver damage. The toxicology of MCYST in mice and rats has been well studied, but little is known regarding genotoxicity in aquatic animals. In this study, the zebrafish, Danio rerio was exposed to crude extract of Microcystis aeruginosa bloom. Liver and heart were examined for MCYST-induced toxicity. Light microscopy at 36 h revealed severe, widespread apoptotic necrosis of the majority of hepatocytes, and cytoskeletal deformation in myocardiocytes. Hepatocytes were dissociated with cell shrinkage and margination of nuclear chromatin. Laddering of genomic DNA from the liver and heart of the exposed fish in an increment of 180–200 bp was consistent with apoptosis. Fluorimetric analysis of DNA unwinding was carried out to determine the DNA strand breakage. After 36 h exposure, the % double-stranded DNA was significantly reduced in hepatocytes and myocardiocytes. In conclusion, the results obtained in this study indicate that, the extract of M. aeruginosa bloom is genotoxic to fish. The DNA damage observed in this study may be attributed to the activation of DNA endonucleases. This model of DNA damage may contribute for identifying novel molecular mechanisms of interest for therapeutic application.

Reproductive dysfunction in females of endangered golden mahseer (Tor putitora) in captivity

The present study was undertaken to gain insight on the physiological basis underlying the constraints in attaining maturity of endangered golden mahseer (Tor putitora) in captivity. Selected hormone levels and stress biomarkers were analysed in wild and captive reared brooders to address the above objectives. As compared to their captive counterparts, plasma 17β-estradiol was significantly (p<0.05) higher in wild caught females. A concurrent trend was observed for plasma vitellogenin, aromatase, 17α, 20β-dihydroxy progesterone (17α, 20β DHP), luteinizing hormone (LH) and11-ketotestosterone (11-KT) indicating a weak hormone response in captive females that potentially hindered maturity. To the contrary, the plasma11-KT levels were not significantly different between wild and captive males. Plasma 17α, 20β DHP level was found significantly (p<0.05) higher in wild caught females compared to females reared in captivity. However, both males of wild and captivity registered significantly higher 17α, 20β DHP than captive females. Plasma 11-KT level was significantly higher in males compared to females. However, the captive females had higher level of 11-KT than captive males. Stress biomarkers viz., cortisol, superoxide dismutase (SOD) and glutathione peroxidase (GPx) were also estimated both in wild and captive brooders. There was no significant difference in plasma cortisol levels of wild and captive reared brooders. However, plasma GPx and SOD activity were significantly higher in captive reared T. putitora as compared to wild brooders counterpart manifesting prevailing oxidative stress in captivity. Overall results showed endocrine and stress differences between wild and captive reared brood fishes during early spawning period which highlighted the endocrine failure of female reproductive maturity in captivity.

Fatty acid, amino acid and mineral composition of rainbow trout (Oncorhynchus mykiss) of Indian Himalaya

The present study was conducted to determine fatty acid profile, amino acid and mineral content of rainbow trout from Indian Himalayan region. The crude protein, crude fat and ash content were 19.44, 5.18 and 1.37% respectively. Protein had a well-balanced amino acid composition, with higher amounts of proline. The highest amino acid score was observed for tryptophan followed by isoleucine. Total monounsaturated fatty acids were high followed by saturated fatty acids and polyunsaturated fatty acids. Oleic acid was dominant, followed by palmitic acid and linoleic acid. Among the n-3 PUFAs, DHA was the most dominant followed by linolenic acid. The ratio of n-3/n-6 PUFA was 0.77. Among the minerals, K was high followed by Ca, Na, Fe, Zn, Se and Mn. From the present study, it can be concluded that rainbow trout has a rich amount of quality protein with well-balanced essential amino acids, PUFAs and minerals.

Aquatic biodiversity in upland streams of kameng drainage in Arunachal Pradesh

The study was conducted to analyze the physicochemical parameters, nutrient variables, plankton and fish diversity in three snow-fed tributaries rivers viz., Dirang chu, Sangti and Tenga of Kameng drainage in West Kameng district of Arunachal Pradesh in the Eastern Himalayas during 2016–17. The key physicochemical parameters in the three rivers viz., temperature, pH, dissolved oxygen were found in the range of 11.42±0.04 to 14.25±0.06°C; 7.32±0.02 to 7.9±0.03; 8.06±0.05 to 8.31±0.05 ppm, respectively. Nutrient variables i.e., ammonium, nitrite, phosphate, alkalinity, hardness were observed in the range of ˂0.01 mg/l; 8.33±0.58 to 11.0±1.0 μg/l; 0.11±0.005 to 0.38±0.03 mg/l; 25.33±2.31 to 17.33±2.31 mg/l; 26.66±1.15 to 15.33±1.15 mg/l, respectively. The rivers being snow fed remained clear and transparent (0.39±0.02 NTU) during the study period. The abundance of plankton species was comprised of Stigeoclonium (50%), Pinnularia (20%), Navicula (15%) at river Dirang chu, whereas Stigeoclonium (30%), Fragilaria (30%) and Lyngbya (10%) dominated at river Sangti, followed by Pinnularia (40%), Acanthidium (20%) and Synedra (10%) at river Tenga. Three species of snow trout (Schizothoracids) remained abundant and formed the major catch with an average length of 24.16 ± 6.17 cm and average weight of 161.2 ± 102.22 g in cast nets and noose and line method. The abundance of diverse plankton groups along with a favorable range of most of the essential hydrological characteristics indicated a good health of the water body and an environment conducive for thriving of snow trout and endowing nutritional security in turn for the mountain dwellers in a remote and fragile Himalayan region of India.

Himalayan Fish Manifest Higher Potential of Quality Nutrients for Human Health

ABSTRACT Five species of snow trout (Schizothorax spp.) were investigated for their inherent nutritional value. Proximate composition, total fat, total cholesterol, triglyceride, fatty acids (FAs) profile, and mineral profiles were analyzed. Protein percentage in all five fish was found to be the same (P > 0.05), ranging from 15% to 18%. Moisture (75–82%) and lipid (1.5–8%) values were found to differ prominently (P < 0.05) in an inverse manner. Total fat (%), total cholesterol (mg/100 g), and triglyceride (mg/100 g) contents were found in the range of 2.73–6.54, 21.31–25.76, and 298.89–342.22, respectively. The trend of FAs in decreasing order was saturated > mono-unsaturated > polyunsaturated (n–6 > n–3). The sum of n–6 FAs value was higher than that of n–3, and the major n–6 and n–3 long chain polyunsaturated FAs (PUFAs) were arachidonic acid and docosahexaenoic acid, respectively. In most of these fish, the profile of macrominerals was phosphorus > potassium > calcium > sodium > magnesium, while the trend for microminerals was iron > zinc > copper > manganese. The snow trout species with best contribution potential to the daily requirement of n–3 long chain PUFAs was found in S. esocinus and S. niger, calcium and phosphorus in S. plagiostomus, and iron and copper in S. progastus.