Environmental inventory and the distribution of inorganic nutrients in a tropical estuary of the south-west coast of India

Dissolved nutrients (PO sub(4)-P, NO sub(3)-N, NO sub(2)-N and SiO sub(4)-Si) estimated in the surface and bottom waters of five selected stations of the Paravur Lake, Kerala, India, during February 1987 to January 1988 revealed distinct seasonal variations. Rainfall and land drainage play significant roles in the nutrient economy, particularly NO sub(3)-N and SiO sub(4)-Si, of this water body. Abnormally high values of PO sub(4)-P indicated extremely polluted condition at the wetting zone of the lake during the premonsoon season. SiO sub(4)-Si showed significant negative relationship with salinity.

Commercial utilization of dolphins (porpoises) in Ceylon

Two species of mammal dolphin are found in waters adjacent to Ceylon, namely the common dolphin (Delphinus delphis) and the bottled-nosed dolphin (Tursiops truricatus). Both these species are predators and cause damage to finishing nets by attacking fish trapped in them. This menace to nets is particularly pronounced when fish populations in a particular area become somewhat depleted. Dolphin can be successfully captured from a motor boat by use of a simple hand harpoon with a detachable dart and bladder buoy. Fresh dolphin meat when placed on the market sold readily despite some local prejudice against the naturally dark colored meat. The flesh of the dolphin is nutritious and can be used successfully in both western and eastern types of cookery.

Feed utilization and wastage in semi-intensive pond culture of mahseer, Tor putitora. (Ham.)

Mahseer, Tor putitora with 12.75, 12.11, and 12.02g of initial weight were fou · J to attain a net weight gain of 12.0 kg, ll.5 kg, and 11.4 kg respectively in pond-1 (commercial feed), pond-2 (farm-made feed), and pond-3 (farm-made feed), respectively against 78.2 kg, 70.3 kg, and 68.1 kg feed fed. Gross energy contents in fish were 1359.3 Kcal/kg, 1281.5 Kcal/kg and 1266.6 Kcal/kg, respectively in pond-1, pond-2, and pond-3 against 3630.4, 3876.9 and 3570.5 Kcal/kg energy in the feed fed. Only 9.4%, 10.5% and 13.7% of the protein, and 8.9%, 3.4% and 3.3% of the lipid fed to fish were converted into muscle respectively in pond-1, pond-2 and pond-3. It was observed that the higher the protein content in feed, the lower the rate of conversion in muscle; the same was also true for lipid. It is supposed that feed derived wastes contribute potentially to water quality deterioration and eutrophication. Lower feed conversion, higher nitrogenous and phosphatic concentrations and higher plankton biomass in the ponds are all supportive to this observation.

Growth performance and nutrient utilization of catfish Clarias gariepinus fed varying inclusion level of fermented unsieved yellow maize

This study was conducted using 150 fish of Clarias gariepinus to investigate the growth performance and nutrient utilization of Clarias gariepinus fed five treatment diets containing varying inclusion level of fermented unsieved maize. The diets were grouped into CT, T1, T2, T3, and T4 with inclusion levels of 25%, 50%, 75%, and 100% of fermented unsieved maize respectively. Highest weight gain was recorded in T4 with value of 10.24 and lowest weight was recorded in CT with 9.17. High FCR were observed in T2 with value of 0.70 and lower value was observed in T4 with value of 0.62. While, T2, T3, and T4 have highest survival rates with values of 90% in each treatment CT and T1 recorded 80% and 70% respectively. There was a significant (p< 0.05) difference between the food conversion ratios treatment T4 with the best value and other treatments. There was a significant (p< 0.05) difference between the levels of fermented unsieved maize inclusion and the specific growth rate of the experimental fish. The highest value of protein level and feed efficiency were observed in T4 at significant difference level (p< 0.05) than other treatments. It was concluded that fermentation of maize in fish feed has positive effects on the nutritional value of the feed. It is recommend that fermented maize can replace raw maize in fish feed diet for growth performance. KEYWORDS: Fermentation, yellow maize, Clarias gariepinus, Fish, Feed.

Growth performance and nutrient utilization of catfish Clarias gariepinus fed varying inclusion level of fermented unsieved yellow maize

This study was conducted using 150 fish of Clarias gariepinus to investigate the growth performance and nutrient utilization of Clarias gariepinus fed five treatment diets containing varying inclusion level of fermented unsieved maize. The diets were grouped into CT, T1, T2, T3, and T4 with inclusion levels of 25%, 50%, 75%, and 100% of fermented unsieved maize respectively. Highest weight gain was recorded in T4 with value of 10.24 and lowest weight was recorded in CT with 9.17. High FCR were observed in T2 with value of 0.70 and lower value was observed in T4 with value of 0.62. While, T2, T3, and T4 have highest survival rates with values of 90% in each treatment CT and T1 recorded 80% and 70% respectively. There was a significant (p< 0.05) difference between the food conversion ratios treatment T4 with the best value and other treatments. There was a significant (p< 0.05) difference between the levels of fermented unsieved maize inclusion and the specific growth rate of the experimental fish. The highest value of protein level and feed efficiency were observed in T4 at significant difference level (p< 0.05) than other treatments. It was concluded that fermentation of maize in fish feed has positive effects on the nutritional value of the feed. It is recommend that fermented maize can replace raw maize in fish feed diet for growth performance.

Utilization of trash fish for human consumption. 3: Studies on the development of fish pickle from Nemipterus japonicus

A method for the preparation of fish pickles from a lean variety of fish namely pink perch (Nemipterus japonicus) is described. Dipping the fish in 10% sodium chloride solution containing 6% acetic acid before pickling, was found desirable for retaining the meaty texture of the product. The product has no fish smell or flavour and has a shelf life of more than six months at ambient temperatures and scored very well in organoleptic tests.

Filleting of fish and utilization of filleting waste

A manual method of filleting of different varieties of fishes yields of skin-on and skinless fillets that can be obtained from them, levels of recovery of picked meat from the filleting waste and the utilization of the latter for the production of fish meal have been reported in this communication. The compositions of meal thus prepared are also given.

Utilization of frog waste

Commercial frog waste samples have been converted into meals by cooking at 0.7 kg/sq. cm for 30 min, draining off the stick water and drying the press cake either in the sun, tunnel dryer under controlled conditions or hot air oven. Yield of the meal varied between 18.6 to 21.5% of the fresh frog waste. Chemical analyses of the meals have shown that the meals prepared from frog waste conform to standards prescribed for fish meal and livestock feed and can therefore be used for supplementation of poultry/animal feed.

Utilization of treated wood, steel, fibreglass, ferrocement and aluminium in the construction of modern fishing boats and their comparative cost analysis

Modern fishing boats have to be built not only on perfect lines but also with sound and strong construction materials that will ensure a long lasting trouble free service commensurate with the heavy capital investment involved. Choice of construction materials for fishing boats need careful scrutiny as they have to perform too well under most aggressive environments-sea-water and marine atmosphere. A number of alternative boat-building materials are now available whose comparative merits and demerits as well as comparative costs are brought out in this paper.

Utilization of sardines

Oil sardine Sardinella longiceps stands out as the single largest pelagic fishery in India contributing to about 30% of total marine fish landings. Commensurate with the volume of the fishery, efforts at proper utilization of the fish by processing into canned and frozen products or by distributing in fresh state to internal consuming centres by quick transport have remained rather very poor. The paper presents the problems and prospects with regard to the utilization of the fish on the above lines. Results of investigations made at C.I.F.T. on the utilization of sardine body oil into industrially useful products such as factice, vehicle for paints, additive in lubricating oil and base for printing ink have also been discussed.

Utilization of prawn waste: isolation of chitin and its conversion to chitosan

process is described for the preparation of chitosan from prawn waste. The process involves extraction of protein using 0.5% sodium hydroxide solution, bleaching the protein free mass with bleach liquor containing 0.3-0.5% available chlorine followed by demineralisation with 1.25 N hydrochloric acid in the cold and deacetylation using 1:1 (w/w) sodium hydroxide solution at 100°C for 2 hours.

Utilization of the fish waste self-brine of fish curing industry as farm fertilizer

Large quantities of self-brine accumulating in curing tanks during the process of commercial fish salting is mostly wasted at present. This liquor exuded from the fish during the process of salting contains considerable amounts of soluble proteins and minerals. Due to the presence of organic matter the self-brine quickly putrefies causing nauseating smell. This renders the whole surroundings insanitary and often leads to health hazards to neighboring localities. Any economic method of utilising this waste brine and converting it into some useful product will be a tangible help to the fish curing industry. Hence, a method is given for converting this waste self-brine into a cheap and efficient fertilizer.