Autobrinometer

An instrument developed for the rapid and accurate measurement of brine concentrations during blanching without disturbing the routine blanching operation is described. The concentration is sensed by a platinum electrode conductivity cell and displayed in a moving coil meter after conversion of the electrical signals into D.C. voltage. The instrument can measure in the range 5 to 12% with an accuracy of ± 1%. The errors caused mostly are those due to wide temperature variations of the brine between 95 to 102°C and the unknown quantities of protein.

Freezer temperature monitor and alarm

An electronic instrument for measuring freezer temperature in the range of +40 to -40°C is described. The salient features of the instrument are remote display (digital and analogue versions with an accuracy of ± 0.1 and ± 0.5°C respectively) and provision for continuous record of temperature. Two types of sensors using thermistor and P. N. function of transistor were used for temperature sensing.

Preliminary account on the intensity of fouling in Karwar waters

Biology of fouling in Karwar waters is presented. The composition of fouling communities, their fluctuations in relation to hydrographical factors such as temperature, dissolved oxygen, salinity and the influence of the nature and texture of the substratum on fouling communities are discussed.

Echo location of fishes in Dhudawa reservoir (Madhya Pradesh)

An investigation was undertaken in order to locate fish using an echo sounder in Dhudawa Reservoir, Madhya Pradesh, India. In general, fish were found to be distributed either towards off-bottom or mid-water areas. Echo sounding is recommended for use in other reservoirs for fish detection.

Stick held drag net for shore line fishes of reservoirs

Observations on the use of stick held drag nets for the removal of shore line fish, which adversely affect the growth of commercially important species in reservoirs, are presented.

One-boat midwater trawling with unequal panelled trawl

Results of the comparative efficiency studies with 10.5 m equal panelled and 10.3 m unequal panelled midwater trawls operated from 10.9 m wooden trawler are presented. Out of the two nets, the latter proved to be relatively good for the capture of off bottom and column fishes like pomfrets, seer, lactarius, catfish, silver bar, ribbon fish and an increase of 84.4% in total catch was observed.

Shore seines for reservoirs - Part 1 - Design and performance

Based on the studies to introduce active gears in reservoirs, a prototype shore seine was designed and tested, the details of which are presented in this communication. The results revealed that the operation of this gear could effectively control the proliferation of under-exploited species.

The effect of increase in the number of fishing trips on the economic efficiency of 9.82 m and 11 m fishing trawlers along Kerala coast

Cost-benefit analysis of a 9.82 m and 11 m fishing trawlers based on the number of fishing trips is presented. The number of fishing trips per year determines the profit and loss of the trawler. With the increase in the number of fishing trips, the profit also increase for both the sizes of trawlers. The minimum quantity of prawn and fish to be landed for 0-20% profit for varying number of fishing trips are worked out. The break-even for 9.82 and 11m trawlers was observed to be 185 and 210 fishing trips respectively during 1980-81.

Studies on frozen storage of minced fish from threadfin bream

Minced fish prepared from threadfin bream (Nemipterus japonicus) was frozen as blocks, packed in polythene lined waxed cartons and stored at -23°C. The changes taking place during storage were followed. There was good correlation between the organoleptic quality, extractability of protein, cook drip loss and weight loss on thawing. The frozen minced fish was acceptable up to 28 weeks under frozen storage.

Studies on lantern fish (Benthosema pterotum) 1. Biochemical and microbiological investigation

Lantern-fish, an under-utilised fish is present in abundance, all the year round in tropical and sub-tropical waters. Biochemical and microbiological studies carried out on lantern fish, caught from the Gulfs of Oman and Aden are reported in this paper.

Proximate composition of five species of flat fishes

Five species of flat fishes, namely Cynoglossus semifaciatus, C. lida, C. bilineatus, C. macrolepidotus and Psettodes erumei caught in trawlers off Mangalore were analysed for proximate composition of different body parts. These data are discussed in terms of their variability and applications. In whole body of C. lida and C. semifaciatus mean values for moisture, protein, fat and ash content on dry basis respectively were 75.9%, 75.3%, 7.1%, 16.1% and 78.9%, 75.6%. 7.9% and 16.6%. Mean values of these constituents of edible parts in the same order for C. semifaciatus and Psettodes erumei were 77.3%, 80.7%, 7.8%, 10.8% and 77.4%, 86.2%, 3.5% and 11.1% respectively.

Studies on lantern fish (Benthosema pterotum) 2. Nutritional evaluation

Various methods for processing and utilization of lantern fish (Benthosema pterotum) are reported. Nutritional evaluation of fish meal and fish hydrolysate from lantern fish has been carried out. Growth rate and PER of lantern fish meal are similar and better than that of the reference protein, casein. Lantern fish meal can therefore be extensively used for the formulation of poultry, fish and other animal feeds as a good protein supplement with beneficial effects.

Denaturation of Labeo rohita (Rohu) actomyosin on frozen storage: preventive effect of carbohydrates

The preventive effect of sucrose and glucose on the denaturation of frozen rohu actomyosin at -20°C for 7 weeks was examined using an in vitro test model. The rate of denaturation was followed by estimating percentage salt extractability, Ca¹²+ ATPase activity and the clearing response test. Sucrose and glucose showed cryoprotective action for all concentration of actomyosin. Higher actomyosin concentration was preserved better than lower concentration. Post-rigor actomyosin was preserved to a greater extent than pre-rigor actomyosin. Correlation between percentage salt extractability and enzyme activity could not be observed in all samples of frozen actomyosin studied.

Packaging and storage studies of dried lizard fish

Packaging and storage studies of salted and dried lizard fish (Saurida sp.) have been conducted using different synthetic films like low density polyethylene (LDPE) of different gauges, high density polyethylene (HDPE) of 200 gauge, polyvinylidene chloride (PVDC) coated 400 MXXT cellophane, 100 gauge polypropylene (PP) and paper laminate of 100 gauge polythene. The films found most effective in the preliminary studies were subsequently used for packaging and storage of dried fish at atmospheric and lower temperature and humidity conditions for confirming their suitability under these conditions. Polyethylene films of higher gauges showed better results under both sets of conditions. PVDC coated cellophane film also performed satisfactorily under the latter conditions which under the former condition got easily attacked by insects. Lower temperature and humidity conditions in general enhanced the storage life of the dried product.

Effect of incubation period on plate count of raw ices and frozen fish

The total viable counts were estimated in one hundred and sixty five samples of raw, iced and frozen fish using incubation periods of 24, 48, 72 and 96h. For raw fish, 24h and for iced and frozen fish 48h incubation of the plates were found to be adequate. Variation between samples was significant at 1% level for raw iced and frozen samples.