Socio-economic dimension of fish farming in Assam

Information on socio-economic framework of the fish farmer community forms a benchmark for policy formulation to develop this economically backward sector. Very few studies have been conducted on the socio-economic aspect of fish farming. Two districts of Assam, Darrang and Nagaon, were selected for this study where 120 respondents from each district were selected randomly. The characteristics representing the personnel and socio-economic attributes of the fish farmers are presented in this paper. The socio-economic status of fish farmers has to be improved by bringing the modern concepts of fish farming to the doorstep of farmers.

Standardization and frozen storage of fish cutlet from bleached and unbleached mackerel mincemeat

In the present study, fish cutlets were prepared from bleached and unbleached mackerel mincemeat. Fish cutlets prepared from bleached meat had scored higher values for taste, flavour and overall acceptability as compared to those from unbleached mincemeat. Fish cutlets prepared with corn flour at the rate of 15% of fish mincemeat had scored higher values for all attributes as compared to other levels. Between the bleached and unbleached mincemeat, the scores for cutlet prepared with bleached mincemeat had higher score than that for the latter. There were no cracks in cutlets prepared with 15% and above corn flour levels as compared to those with lower levels. Fish cutlets prepared from bleached and unbleached mincemeat with spice mixture at 20 and 30% of the fish mince, respectively, had higher scores for taste, flavour, texture and overall acceptability as compared to those with other levels. Organoleptic quality of cutlet prepared from bleached and unbleached mackerel mince did not show changes in the appearance, colour and texture during storage. Changes were more prominent in flavour, taste and overall acceptability. Fish cutlets prepared from bleached mincemeat were acceptable for two months and those from unbleached mincemeat were acceptable up to one month from the point of view of organoleptic and biochemical qualities.

Bacteriology of chilled water during the preservation of fish

Except for the preliminary studies at Torry Research Station in Scotland, no results have been reported on the succession of the bacterial flora during the storage of fish in chilled water. The present work was undertaken to elucidate the dynamics of bacterial population changes in chilled fresh water under comparable conditions of storage in melting ice (+1° to +3°C.) which has been earlier studied by de Silva in 1960.

A Review of the parasitic copepods of fish recorded from Ceylon with description of additional forms

The beginning of our knowledge of the copepods parasitic on fish from Ceylon is due to Bassett-Smith (1898 a) who, in a paper on "Further New Parasitic Copepods found on Fish in the Indo-Tropical Region", included seven species collected at Trincomalee and Colombo. Later in the same year, in a paper on "Some New or Rare Parasitic Copepods from the Indo-Tropical Region", he (Bassett-Smith, 1898 b) included three more species from Ceylon. Soon after, more of these parasites were obtained from Ceylon during Herdmann's investigation of the Pearl Banks. From this collection, one lot consisting of eleven species was described by Thompson and Scott (1903) and a second lot consisting of seven species was described by Wilson (1906). At that stage the number of species recorded from Ceylon made up to a total of twenty-eight and there the matter rested for another quarter of a century until, quite by chance, while collecting marine animals on a reef, Mr Kirtisinghe came across a newly dead half-beak with a learned parasite projecting from its body. Since then, in a number of occasional papers (Kirtisinghe, 1932-35, 1937, 1950, 1956, 1960) he has described thirty-eight more species of parasitic copepods from Ceylon. However, his collection included many more species which were put aside for later attention. In the present paper, while dealing with those forms in his collection which he has not recorded or described earlier, he has put together all the known forms of parasitic copepods of fish from Ceylon. A list of the host fishes with their respective parasitic copepods is also provided, types of new species, at present in the author's private collection, will be deposited in the Fisheries Department, Colombo, Ceylon.

The processing of fish and other marine resources

The preservation of freshness in fish (commonly referred to as fish handling) and the conversion of fresh fish into other products can both be considered as methods of processing. In commercial practice, however, the term "processing" is confined to the conversion of fresh fish into other products.

Processing and marketing of fish with special reference to export of pelagic fish and fish products

The paper describes the world tuna fishery, industry and markets and the trends for its future development. The prospects for developing a tuna export industry in Sri Lanka are discussed. Suggestions are given as to products composition, international co-operation and utilization of available processing facilities. The need for industry and export support is stressed, and it is concluded that preparations for the development should start well in time.

Studies on the preparation of fish silage. 1. Effect of quality of raw material and type of acid

An experiment was undertaken in which silver bellies (Leiognathus splendens) of different quality were used to produce silages using different concentrations of hydrochloric acid and formic acid. The quality and storage life of the various preparations are reported. Silages which keep for at least 30 days can be produced from silver belly held for 3 or 12 hours at 28°C by: 1) reducing the pH by addition of hydrochloric acid; 2) adding 0.5% formic acid and reducing the pH to 3.5 with hydrochloric acid; or 3) adding 2.5% formic acid.

Studies on the preparation of fish silage. 2. Rate of liquefaction in different parts of silver belly

An experiment was undertaken to determine from which part of silver belly (Leiognathus splendens) carcasses originate the autolytic enzymes responsible for liquefaction of silage. Findings show that it is important to leave head and viscera present in order to get a satisfactory liquefaction in silage prepared from silver belly using 3.5% formic acid. The storage life of silage produced from various parts of the fish carcasses is also discussed.

Studies on the preparation of fish silage. 3. Dried silage products

An investigation was undertaken on the production of dried products from silver belly (Leiognathus splendens) silage mixed with plant filter materials. Silages produced using hydrochloric acid and/or formic acid when mixed with rice bran or maize meal and dried, yielded powders having an acceptable appearance and a pleasant odour, which are suitable for use in compounded chicken feeds.

Studies on the preparation of fish silage. 4. Economics of production

Economic aspects of producing liquid and dried silage from silver belly (Leiognathus splendens) in Sri Lanka are considered. A discounted cash flow analysis for the production of a dried fish silage/rice bran product suitable for use in compounded poultry feeds shows that the internal rate of return for a 10-year project would be between 34-77% and for a 5-year project between 26-73%. Thus it is concluded that the project would be extremely profitable.

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.

Impact of Bashundhara Baridhara Housing Project on the status, abundance and species diversity of fish in Bashundhara Housing lake in Dhaka, Bangladesh

A study on the status of fisheries and environmental impact assessment (EIA) was conducted on Bashundhara Baridhara Housing Project (BBHP), Dhaka, Bangladesh for prediction and measure the effects of housing project related development activities that have already been implemented and planned for future implementation. The project is still under development phase and so far allotted 10,000 plots of different sizes. The study shows that the original water bodies and natural fish production there from have greatly declined due to earth filling carried out for development of land for the housing. The physico-chemical parameters of the existing water body within the project area were found to be suitable for fish farming in the estate. A number of economically important fish species are found available in the existing lake. However, the natural fisheries resources of the existing lake is under great stress due to the changes made in the ecosystem, siltation, construction of building and dumping of house building and household waste materials. This has caused some important fish species of the lake to become critically endangered and vulnerable which have been documented in this paper. Appropriate regulatory and mitigating measures with respect to water management, disposal of construction garbage and other biomedical toxic substances far away from the water bodies are required to be taken to keep the water safe and suitable for fish production as well as for multipurpose use of the lake water.

Present status of harvesting, transportation and marketing of freshwater Small Indigenous Species of Fish (SIS) of Bangladesh

A survey conducted to evaluate the present status of harvesting, transportation and marketing of freshwater SIS of Bangladesh showed that among the 56 to 73 species of small indigenous fish species (SIS), mola (Amblypharyngodon mola), dhela (Osteobrama cotio cotio), puti (Barbodes sarana), tit puti (Puntius ticto), tengra (Mystus vitatus), chapila ( Gudusia chapra), batashi (Pseudotropius atherinoides), buzuri tengra (Mystus tengra), katchki (Corika soborna), gol chanda (Chanda ranga), lamba chanda (Chanda nama), phul chela (Chela phulo) and lata (Channa punctatus) are the most common. But the abundance of the mola, puti, tengra, batashi and chapila are higher than the other SIS species. Puti was at the top of the list in percentage abundance (7-9%), followed by mola (7-8%), tengra 6-7% and chapila 5-6% in all the investigated areas. Three levels of market or marketing systems were observed in the distribution channel of fish trade: primary, secondary/higher secondary and final consuming markets. Primary market is the catching point in the rural area. In secondary market, the collectors bring the fish from primary market to the landing ghats, usually to the nearest thana market or at a place well linked by rivers, road and rail transport. On purchasing the fish from the higher secondary market, the paikars sell the fish to the retailers who take it to the final consumer market. Different types of crafts and gears are used for catching the SIS in Bangladesh. Monofilament gill nets (20%), traps and line nets (25%) and seine nets (25%) are the dominant gears in respect of the total catch followed by lift net (10%) and cast net (20%). A total of 10 types of gear are listed according to their mode of operation which used for catching SIS. The processors in consumer market received higher marketing profit followed by primary market and secondary market, respectively.

Microhabitat breadth of fish community along the Vamanapuram River, south Kerala

The microhabitat breadth of Vamanapuram River fish community was studied in detail. The microhabitat variables selected were relative depth, focal point velocity, water column depth, mean water velocity and substrate. Puntius filamentosus had the highest breadth in three dimensions in both stream and river habitats showing a generalistic mode of resource utilization. Garra mullya, Labeo dero and Glossogobius giuris are specialists in the usage of microhabitat variables in the stream habitat while these are G. mullya, Etroplus maculatus and Aplocheilus lineatus in river habitat. Danio aequipinnatus showed extreme variations along focal point velocity variable in both habitats indicating an. opportunistic behaviour.

Study of fish diversity in Nira River

Fish diversity in Nira River in Pune District has been studied. The study revealed the presence of 24 species of fish belonging to eight orders (Cypriniformes, Siluriformes, Perciformes, Osteoglossiformes, Synbranchiformes, Clupeiformes, Mugiliformes and Aulopiformes). The predominant orders of fishes in this area (Sangavi) are Cypriniformes, Siluriformes and Perciformes. The highest number of ten species was recorded in the order Cypriniformes. The fishes recorded were found to be widely distributed and were present in good numbers in the river.