Studies on the probable sources of fungal infection and the control measures in a fish seed farm

The causes of mortality of fry of cultivable fishes in a fish seed farm were investigated. The mortality was due to fungal infection and the pathogen was Saprolegnia sp. The sources of infection were unhygienic breeding hapas, spawnery hapas in the cemented ponds, hatching jars and excess feeding. Application of one kg slaked lime followed by 75g of CuSo sub(4)(l-0.5 p.p.m.) and 150g of KMno sub(4)(2-1 p.p.m.) per each nursery (158m³ water) controlled the pathogen.

Studies on the occurrence of enteric bacteria in the estuarine waters along the Mangalore coast

Occurrence of enteric bacteria in water, sediment and shellfishes of Mulki, Pavanje, Gurpur and Netravathi estuaries of the Mangalore coast is reported. 70 water samples, 71 sediment samples and 37 shellfish samples were analysed in 18 months. Total bacterial load in sediment and shellfishes was found to be more than that in water samples. The total bacterial load was not very high. However, enterococci, particularly coliforms in sediments, water and shellfishes were found to be quite high, indicative of faecal pollution. The incidence of Salmonella spp. was recorded in all the estuaries except the Mulki estuary.

Studies on the effect of leaching on the quality of ice-stored fish

A comparative ice storage study of milk fish (Chanos chanos) in direct contact and out of contact (in 200 gauge polyethylene bag) with ice was taken up to assess the effect of leaching on quality of ice-stored fish. It was observed that the leaching effect was more significant on TVN and NPN than that on cc amino nitrogen components while there was very little effect on bacterial load. It is concluded that under similar conditions of icing, fish out of contact with ice will have longer shelf life and more acceptability than the fish preserved in contact with ice.

Studies on the toxicological effects of Asulox-40 and Emisan-6 to eggs and early life history stages of Sarotherodon mossambicus

Toxicological effects of Asulox-40 and Emisan-6 to eggs and early life history stages of Sarotherodon mossambicus were reported. 80% of egg hatching occurred in the controls, 1 p.p.m and 5 p.p.m concentrations of Asulox-40. 10 p.p.m. and 50 p.p.m. concentrations of the same toxicants had 70% and 60% hatchings while in Emisan-6 in the same concentrations the hatching were 70% and! 40%. In 100 p.p.m. concentration of both toxicants 20% incomplete hatching occurred. In Emisan-6 Lc 50 and Lc 100 values were recorded at 32 hand 96h respectively in 10 p.p.m. concentrations. In Asulox-40 the same values were recorded in 24h and 40h respectively at 50 p.p.m. concentration. The fish activity during the experimental period showed initial hyper activity. It was established that the Emisan-6 is more harmful to S. mossambicus than Asulox-40. The harmless concentrations of these chemicals were 1.2 p.p.m. for Asulox-40 and 0.6 p.p.m. for Emisan-6.

Studies on Thiobacilli spp. isolated from sandy beaches of Kerala

Occurrence, isolation and oxidative activity of Thiobacilli spp. from some sandy beaches of Kerala are reported. These organisms were encountered in polluted beaches and were dominant during monsoon in all the beaches.

Studies on kraft paper used for liners and corrugating media of shipping containers for frozen shrimp

An examination was made of the physical properties of kraft paper used for liners and corrugating media of shrimp shipping containers in India. Findings stress the need for use of virgin grade kraft paper and adequate waxing treatment on both sides for water proofing.

High temperature processing of fish sausage 3. - Studies on some of the storage characteristics

The proximate composition of the high temperature processed fish sausage was found to be 14.56% protein, 4.65% fat, 69.14% moisture, 2.12% ash and 8.12% carbohydrate. The quality of the product during storage was assessed on the basis of the changes observed in the physical, chemical and microbiological parameters. The results of the different tests such as pH, volatile base nitrogen (VBN), trimethyl amine nitrogen (TMA-N) and jelly strength are summarized and discussed. The total bacterial load increased gradually during storage but was not proportional to the initial load.

Biochemical studies on crab Scylla serrata

Studies on the biochemical composition of crab meat from body and claw revealed marked differences in relation to flavour. Protein content is on the higher side in crabs (19.1 to 20.9%) with high percentage of free amino acids and phosphorus and less carbohydrate and fat. The variation in composition due to the presence of eggs in female crabs and the importance of claw liquor and its composition are reported.

Studies on dried/smoked barracuda

Physical, chemical and organoleptic characteristics of dried and smoked barracuda (Sphyraena spp.) during storage at ambient temperature are reported. Initial increase in total volatile basic nitrogen (TVBN) content after drying as well as smoking did not have any significant effect on the organoleptic qualities of the products. Smoking was found effective in delaying the onset of fungal attack and also in improving the organoleptic qualities.

Studies on iced storage of common murrel (Channa striatus)

The iced storage characteristics of common murrel (Channa striatus) have been studied. The non-protein nitrogen and alpha amino nitrogen in the muscle of the fish decreased during iced storage and the total volatile base nitrogen at the end of iced storage was not high even though the fish became unacceptable during the period. There was steep decrease in total bacterial count during initial storages of storage and then increased steadily on further storage. The fish remained in acceptable condition for 8 to 9 days in ice.

Studies on frozen characteristics of individually quick frozen and block frozen mackerel

Studies on mackerel (Rastrelliger kanagurta) of medium (4%) and high (11%) lipid contents quick frozen individually (IQF) and as blocks (BF) and stored at -23°C showed that block frozen mackerel had higher frozen storage shelf-life than individually quick frozen samples. IQF samples of medium and high lipid contents had shelf-lives of 17 and 20 weeks whereas BF samples of both series had 23 and 24 weeks respectively based on sensory evaluation.

Studies on morphometry and hydrology of Gandhisagar Reservoir with special reference to its fisheries

Gandhisagar, the second largest reservoir of India is located in Mandsaur district of Madhya Pradesh at latitude 24°44'N and longitude 75°33'E at an altitude of 403.56m MSL in orientation from NE to SE. It has an extensive water spread area of 66000 ha at full reservoir level with a maximum and mean depth of 49.52 and 11.73 m respectively. The maximum length and width of the reservoir are 112 and 16km having a total shore line of 442km. Details of catchment area, bathymetry, standard hydrological data giving water level relation of the basin to water spread area, volume and fish production and the bottom topographical details of 11 experimental fishing stations and 6 fish landing centres are discussed.

Studies on frozen storage of cuttle fish fillets

The freezing and cold storage characteristics of cuttle fish fillets have been studied. The yield of fillets from cuttle fish was about 35% and the fillet had an average moisture content of 76.85% and fat 0.82% During storage at -20 ± 1°C for 16 months the salt soluble nitrogen of the fillets decreased from 85.1to35.36%, the non-protein nitrogen from 24.61 to 20.84% and alpha amino nitrogen from 252 to 140mg/100g. Initially the fillets were white in colour, showed signs of desiccation by 4 months storage which increased on further storage and the fillets finally became dull white with yellow discolouration inside. The firm and chewy texture of the cooked fillets changed to rubbery even though the product was slightly sweet at the end of that storage period of 16 months.

Studies on freezing and storage of Psenopsis cyanea

The freezing and storage characteristics of Psenopsis cyanea caught on board FORV Sagar Sampada from a depth of 350 m off Cochin are reported. The fat content of the fish was high (15.58% on the weight of whole fish) and the meat was white in colour. Peroxide value, free fatty acids and thiobarbituric acid values increased during frozen storage and organoleptically the fish was acceptable up to 32 weeks at -22 ± 1°C.

Studies on lipolytic bacteria in stored fish Etroplus suratensis (Bloch)

The distribution of total hectrotrophic bacteria (THB) and lipolytic bacteria in various regions (body surface, gill, intestine and flesh) of fish Etroplus suratensis (Bloch) during storage at 28 ± 2°C and 4°C was studied. Pseudomonas dominated at reduced temperature whereas at 28 ± 2°C and in fresh condition Vibrio, Aeromonas, and Acinetobacter dominated. Lipolytic activity was elaborated by the members of various genera and their activity varied in different lipid compounds (tributyrin, tween 80, tween 60, tween 40 and tween 20). Tributyrin was utilized by majority of the isolates. All the selected isolates preferred a temperature of 35°C and pH 6.0 for their maximum growth. Aeromonas and Vibrio showed maximum growth at 0.5% NaCl concentration while 3% NaCl was found to be optimum for Pseudomonas.