Studies on the biochemical composition of some freshwater fishes. Pt. 1. Muscle

Twenty five different species belonging to 16 genera of freshwater fishes were analysed for protein, fat, moisture, ash, carbohydrate, phosphorus, calcium and total iron content in their muscle. Calorific value for protein, fat and carbohydrate fractions and total calories for each species were also calculated.

Biochemical aspects of the spoilage of prawns

Certain features characterise spoilage of sea foods, as distinct from spoilage of protein foods in general. Among sea foods spoilage differs in the crustaceans, teleosts, or elasmobranchs respectively. High levels of free amino acids concentrations are characteristic of prawns and other crustacean muscle. Changes occurring in these influence pattern of spoilage. Differences also exist in the sea prawns and prawns taken from the backwaters. Melanosis is a characteristic feature of spoilage in prawns. Observations have shown that prawns are very susceptible to spoilage at ordinary temperature, the period of absolute freshness not exceeding 4 hours, while prompt icing extends the period to 3-5 days.

Studies on the biochemical composition of some freshwater fishes. Pt. 2. Liver

Although considerable work has been done on the composition of fish liver oils, most of which includes the study of various vitamins and fatty acids, little attention has been paid towards the composition of fish liver as a whole.

Studies on the biochemical composition of some freshwater fishes. Pt. 3. Ovary

Biochemical composition of the spent ovaries of 23 different species of freshwater fishes showed a much lower value for protein and fat with higher moisture content than those of the ripe eggs, suggesting an inverse relationship between fat and moisture. Ovaries during the recovering phase showed fairly high values of phosphorus, but lower than those for the ripe eggs. Higher values of calcium and iron in spent ovaries than those in ripe eggs probably suggest that there is a greater requirement of calcium and iron during the spent phase of the gonads.

Studies on the biochemical composition of some freshwater fishes. Pt. 1. Muscle

Twenty five different species belonging to l6 genera of freshwater fishes were analyzed for protein, fat, moisture, ash, carbohydrate, phosphorus, calcium and total iron content in their muscle. Calorific value for protein, fat and carbohydrate actions and total calories for each species were also calculated.

Biochemical composition of the muscle of some freshwater fishes during the pre-maturity phase

Biochemical composition of the muscle of juveniles belonging to 18 different species of freshwater fishes showed that the protein percentage in juveniles was higher than the adults. The fat, on the other hand, was much lower. This suggests that the body fat increases with the onset of maturity. No clear inverse relationship was found between fat and protein in juveniles. Moisture percentage was very high in juveniles. This was probably because of low fat content. In most species the sum of fat and water contents (F + W) was found to be constant. The percentages of ash, calcium and phosphorus were higher in juveniles than those of adults. Dry matter percentage varied inversely with the moisture and in most species carbohydrate was generally low. In juveniles although the calorific value of protein-fraction was high the total calorific value was lower than the adults.

Studies on the post-mortem changes in shrimp and prawn during ice storage. Pt. 2. Biochemical aspects of quality changes

Studies were conducted on biochemical changes in P. monodon and M. rosenbergii during ice storage. At the end of 10 days of ice storage, moisture and protein content of freshwater prawn slightly decreased from 78.34 to '77.35% and 18.46 to 17.10, respectively, while lipid and ash content slightly increased. The moisture, crude protein, lipid and ash content of one day ice stored tiger shrimp samples were 78.07, 18.06, 1.3 and 1.29% respectively. The protein composition of freshwater prawn immediately after killed were 36.51% sarcoplasmic, 44.63% myofibrillar, 8.12% stroma and 6.44% alkali soluble protein. At the end of 10 days of ice storage, sarcoplasmic and stroma protein slightly decreased while there was little or no changes observed in myofibrillar and alkali soluble protein. In case of one day ice stored tiger shrimp, the composition of protein were 35.32% sarcoplasmic, 46.29% myofibrillar, 7.86% stroma protein and 7.08% alkali soluble protein. At the end of 10 days in ice, sarcoplasmic protein decreased from 35.32% to 32.16% while there was slight change in other protein fractions. The TVB-N value of 1 day ice stored shrimp was 10.5 mg/100g of sample. It increased gradually with the lapse of storage period and at the end of 10 days storage in ice, the value increased up to 60 mg/100g sample. The tiger head on shrimp in ice storage were found organoleptic acceptable condition for 8 days and at that time the TVB-N values were 32.2 mg/100g which is slightly above the recommended limit for TVB-N for export.

Sulfide binding characteristics of blood serum in Calyptogena pacifica and Vesicomya gigas

The sulfide binding characteristics of blood serum were studied in vitro in two deep-sea vesicomyid clams, Calyptogena pacifica and Vesicomya gigas. Both the C. pacifica and the V. gigas serum concentrated sulfide at least an order of magnitude above ambient levels. V. gigas accumulated sulfide faster than C. pacifica, reaching saturation at 5000 M after an hour. C. pacifica bound sulfide at half the rate of V. gigas, reaching saturation in about two hours at a substantially higher concentration of sulfide. The observed distribution of the animals near cold seeps in the Monterey Submarine Canyon can be explained by their different sulfide binding abilities. The hypothesis that cold seeps are actually much more unstable sources of sulfide than previously assumed is explored.

Indices and fecundity of a threatened freshwater catfish Mystus montanus

Fecundity of threatened catfish Mystus montanus was estimated from a collection of gravid females, which ranged from 290 to 27,972 according to body length and weight. The relationship between fecundity and BL, BW, GL and GW was analyzed by linear regression, which showed both positive and negative correlation. Gonado-somatic index (GSI), hepato-somatic index (HSI) and spleen-somatic index (SSI) ranged from 0.135 to 21.28, 0.358 to 21.33 and 0.126 to 1.08 in females and the corresponding values for males were 0.17 to 10.68, 0.619 to 3.25 and 1.25 to 2.33 respectively.

Effect of Neemta 2100 toxicity on acetylcholinesterase and serum glutamate oxaloacetate transaminase enzymes in serum of fish, Oreochromis mossambicus

Acetylcholinesterase and serum glutamate oxaloacetate transaminase enzymes have been used as marker monitoring the effect of neem seed based pesticide Neemta 2100 on the fish, Oreochromis mossambicus. Fishes exposed to sublethal concentrations of Neemta 2100 for acute periods of 24 and 48 hours were sacrificed to determine enzyme activities in serum affected due to toxicity. Laboratory studies of in vivo exposure of this pesticide showed synergistic inhibitory effect during acute period of toxicity. Acetylcholinesterase was noticed as 6.25 µm substrate hydrolyzed/mg protein/hour and serum glutamate oxaloacetate transaminase was noticed as 36.71 µm substrate hydrolyzed/mg protein/hour in control fish serum. Significant decrease in GOT level in Neemta 2100 treated fishes after short term exposure indicated its severe toxicity to fish.

Purification and characterisation of immunoglobulins from the serum of a catfish, Clarias gariepinus (Burchell, 1822)

Attempts have been made to characterize and purify immunoglobulins from the serum of Clarias gariepinus, which has been immunized with bovine serum albumen. Initially, the proteins in the serum were chromatographed successively by affinity chromatography column. The affinity-purified fraction was concentrated and checked in SDS-PAGE, two bands of heavy chain and two bands of light chain were observed. Since teleost immunoglobulins have been shown to belong to a single class, the extra bands in light and heavy chains in the present study might be the breakdown of immunoglobulin or some unpurified contaminants. The affinity-purified fraction was also subjected to gel filtration chromatography column.

Effect of lykamin on growth and biochemical composition of long whiskered catfish, Mystus gulio (Hamilton) fingerlings under laboratory conditions

A growth trial was conducted to test the effect of Lykamin (dietary supplement) on growth, survival and feed conversion in Mystus gulio. Four isoproteic diets were formulated by incorporating the growth promoter, Lykamin at the levels of 0, 0.25, 0.50 and 0.75% diet. The crude protein content was 30% in each diet. The diets were fed to triplicate groups of catfish fingerlings twice daily at a level of 5% of the total body weight for 120 days. Regular fortnightly sampling was done to evaluate the growth performance of the experimental animals. Water quality parameters during the experimental period were maintained within the range suitable for catfish. The results showed better specific growth rate, weight gain, protein efficiency ratio and feed conversion ratio in the group which was given 0.75% Lykamin diet.

Evaluation of biochemical characteristics of a traditional salt fermented fish product of northeast India with special reference to its flavour components

'Lona ilish', is a traditional salt fermented fish product, widely consumed and very popular in north-east part of India and Bangladesh. It is prepared exclusively from a high fat fish, Hilsa (Tenualosa) ilisha. 'Lona ilish' was prepared in the laboratory following traditional process. After 150 days of fermentation, a better quality 'lona ilish' was obtained. Biochemical characteristics of market sample was estimated and compared with the laboratory prepared one. A variation in biochemical composition was observed. Sensory quality of the final product of laboratory prepared 'lona ilish' was compared with the market sample and found that the laboratory prepared product scored better than the market sample. The moisture (49.89%) and salt (15.48%) of the final product was found to be satisfactory for stability of the 'lona ilish' at ambient temperature. Analysis of volatile compounds of 'lona ilish' was done using GC-MS. It was concluded that, aldehydes, ketones and esters may possibly contribute characteristic aromas to the overall flavour of the salt fermented hilsa.

Size related feeding patterns and electivity indices of silver barb (Barbodes gonionotus Bleeker) from a pond, Bangladesh

The feeding patterns with respect to quality and quantity of food of silver barb, Barbodes gonionotus varied with their size and development. The results indicated that the fish in the size group I (7-25 mm TL) were fairly omnivore with particular liking for rotifera, green and blue-green algae while the size group II (25.1-44 mm TL) and III (44.1-55 mm TL) were omnivore with higher tendency of feeding on debris, aquatic plants, green algae, blue-green algae and rotifera. However, the fish of the size group IV (55.1-80 mm TL) were found to be herbivore with feeding preference for aquatic plants, green and blue-green algae. In all the size groups, debris was the most dominant food item. Feeding preference of the fish showed clear ontogenetic shift. The electivity indices revealed that the fish were selective feeder.

Selective biochemical studies in a freshwater prawn, Macrobrachium nobilli(Crustecea: Palaemodinae)

Calcium and phosphorous contents of abdomen and cheliped muscles of juvenile, male and female Macrobrchium nobilii were determined from field collected samples. In all the three groups calcium concentration was higher in chelipeds while the phosphorous content was more in abdomen muscles than in the chelipeds. However between three groups the calcium content varied significantly both in the abdomen and cheliped muscles (P