Hydrological studies of Matatilla Reservoir, Uttar Pradesh

Matatilla Reservoir, located in semi arid region, (Lat. 25 degree 15'N and Long. 78 degree 23'E) has an area (at FRL) of 13,893 ha, volume and shore development 0.663 and 1.65, shoreline 73.6 km. Volume and shore development indicate that greater part of the reservoir is shallow, which is a favourable point for fish productivity. Temperature and dissolved oxygen gradually decreased with the increase in depth. Carbon dioxide was absent from the surface but invariably present in the bottom (3.6 ppm) pH remained alkaline (7.2-8.4 ppm) throughout the year. Alkalinity, chloride, calcium, magnesium, hardness and priductivity was maximum in pre-monsoon and minimum in monsoon except for calcium and manganesium in post-monsoon. Phosphate, nitrogen and ammonical nitrogen were found in traces. These variations may be due to influx and outflow of water and use of reservoir water for multipurpose activities.

Fish and shell fish fauna of the retting and nonretting zones of the Kadinamkulam kayal, Kerala

Retting of coconut husk is one of the major problems of pollution in the estuaries (kayals) of Kerala. Retting activity has resulted in the mass destruction of the flora and fauna and has converted sizeable sections of the kayal into virtual cesspools of foul smelling stagnant waters. Levels of hydrogen sulphide, phosphate and BOD, increased while dissolved oxygen and fish and shellfish fauna decreased in the ambient waters. In the Kadinamkulam kayal a total of 37 species of fishes belonging to 26 families, 5 species of prawn and 2 species each of crabs and molluscs were recorded from the no retting zone, whereas only 20 species of fish in dead condition were collected from the rating zone. Prawns, crabs and molluscs were absent at the vetting zone. Majority of the fish fauna in the kayal were marine forms.

Quality aspects of some exportable dried fishery products of Bangladesh

A study was conducted to evaluate the quality aspects of eight exportable dried fishery products of Bangladesh. The products were evaluated by examining organoleptic properties, water reconstitution behavior, microbiological and biochemical aspects. The water reconstitution rate was faster in ribbon fish and Bombay duck, and slower in other fishes and air bladder and shark fin products. Organoleptic and physical characteristics in respect of color, odor, texture, insect infestation and broken pieces of the products revealed that all of the products were either in excellent or acceptable condition. Total viable bacterial load ranged from 0.95 x 104 CFU/g to 1.8 x 104 CFU/g in dried products. Coliform bacteria was absent in all the dried fishery products. The results of moisture, crude protein, lipid and ash content of the products ranged from 16.20 to 23.51%, 58.37 to 82.86%, 0.17 to 14.44% and 0.58 to 9.23%, respectively. Non-protein nitrogen (NPN) contents were in the range of 0.104 to 2.372% and the pepsin digestibility values were of 88.41 to 94.23%. The results of the study suggested that the exportable dried products were of good quality and hygienically safe.

Bacterial quality and depuration of the green mussel Perna viridis from natural beds

Green mussel (Perna viridis) and sea water from their natural beds on the coastal areas of Porto Novo were studied between April and August 1996 for their bacterial quality. Water samples from the beds were also analysed for their physico-chemical parameters. The total bacterial count of mussels from natural beds as well as bed waters ranged 10³ organisms per gram of mussel meat suspension and per milliliter of sea water. The faecal coliforms were found to be within the permissible limits. Pathogenic bacteria such as Salmonella spp., Streptococcus spp. and Staphylococcus spp. were absent. The variations in pH, temperature, salinity and dissolved oxygen of the seawater samples were insignificant. The mussels were subjected to depuration by different methods among which chlorination was found to be most effective.

The freshwater zooplankton of Sri Lanka, with a discussion of tropical freshwater zooplankton composition

Based on the study of over 500 zooplankton samples collected in Sri Lanka during 1965-1974, the species composition from different habitats is analysed. The zooplankton assemblage is typically tropical with relatively few species of Cladocera and Copepoda. The Rotifera include a large number of species of the genus Brachionus. The limnetic zooplankton resembles the pond zooplankton closely in that all the eurytopic species found in the different types of habitats, including ponds; also occur in the limnetic zooplankton. The large Cladocera belonging to the genus Daphnia are very rare. In general, large zooplankters are absent. The size composition of the zooplankton has a smaller range than in temperate regions. This is due to the absence of large-sized zooplankton species. The reasons for the differences in species variety and size composition between zooplankton of temperate and tropical regions is perhaps due to a number of factors. These include the effects of high and uniform temperatures, food availability and predation by fish and invertebrates.

Laboratory culture of Moina with organic ana inorganic fertilizers

An experiment was conducted in the laboratory condition to determine the effect of organic (poultry drop, cow dung and mustard oil cake) and inorganic fertilizer (urea) on production, reproduction rate and maturation time of Moina species. Production rate was also determined in both aerated and non-aerated system in plastic containers with carrying capacity of 2.5-liter each. Total production was significantly higher in both aerated (2475 individuals/2.5 l water) and non-aerated (3253 individuals/2.5 l water) containers using poultry manure compared to other fertilizers. Moreover, the reproduction rate and maturation time in poultry drops showed distinct efficacy in Moina species. Reproduction rate of 11 individuals was the maximal while lowest maturation time was found 78 hours. Reproduction and maturation were induced surprisingly in test tube where the aeration system was absent.

Hydrography of the Bay of Bengal during south west monsoon and its significance on oil sardine fishery

Hydrographic data collected from east coast of India during 1994 monsoon period revealed that these waters are highly characterized by upwelling especially in the coastal waters with more intensity in the southern part of the region. However, the near surface salinity stratification consequent to high fresh water inflow into the bay was absent in the present study. Oil sardines are directly influenced by hydrographic parameters such as salinity and temperature and stratification of these parameters are the major reasons for non-availability/migration of oil sardine from this region in the earlier years. Considering the recent topographical change in the east coast coupled with hydrological stability an attempt has been made in this paper to give reasonable justification to the reported bumper catches of oil sardines from 1994 on wards in the east coast of India.

Bioactivity of epidermal secretion of two marine catfish from Mumbai

Crude mucus and its partially purified fractions from two marine catfish from Mumbai, Arius dussumieri and Osteogeneiosus militaris were assayed for their crinotoxicity through assays for hemolysis and haemagglutination of chicken erythrocytes, formation of paw edema in mice, and antibacterial activity against one gram-positive and four gram-negative bacteria. Assays were also done to block the edema using Phineramine maleate, Piroxicam, and Atropine sulfate. Crude toxin as well as their fractions from both the fishes exhibited haemolytic and haemagglutinating activities on chicken blood, besides edematous activity in mice models. The edematous activity was blocked by Phineramine maleate and Piroxicam but enhanced by Atropine sulfate; however, all these activities, either blocking or enhancing, were statistically insignificant. Antibacterial activity was absent in all the extracts tested.

Studies on the occurrence and growth rates of two intertidal fouling bryozoans in the Mattancherry channel of Cochin harbour, south-west coast of India

Occurrence and growth rates of two species of intertidal fouling bryozoans namely Electra bengalensis (Stoliczka) and Electra crustulanta (Pallas) are presented in this paper. The former was a typically marine form, settling on panels only during the high saline conditions of the pre-monsoon period and were absent during the low salinity conditions of the monsoon period, while the latter appeared to be a typical brackish water form settling on panels during the low saline conditions existing during the monsoon and post-monsoon periods and were totally absent during the pre-monsoon months. Regression co-efficient of the former was higher than that of the latter suggesting more pronounced growth in Electra bengalensis. Maximum growth for this species was noticed during March, April and May (pre-monsoon) while for the other species growth was more or less similar during monsoon and post-monsoon months (June-January) showing that the species was at home in oligohaline and mesohaline waters.

A bacteriological study of the natural flora of edible oyster, Crassostrea madrasensis

The total viable bacterial populations in the oysters and the sea water from the edible oyster farm at Tuticorin were in the range of 10 super(3) to 10 super(4) per ml and 1 super(2) to 10 super(3) per ml respectively. The maximum most probable number of faecal coliform recorded during the one year period of study of both the oysters and seawater were 33 per 100 ml. Pathogenic bacteria (Salmonella sp., Vibrio cholerae, coagulase positive staphylococci and faecal streptococci were absent in oysters and farm water. Study of 197 (98 taken from oyster liquid and 99 from oyster farm water) randomly isolated cultures indicated that gram negative asporogenus rod-like bacteria of the Vibrio, Flavobacterium, Achromobacter and Pseudomonas groups were the dominant flora of the oyster liquid as well as seawater.

Quality of fish preparation served in catering establishments of Bombay

The results of the study carried out on the quality of fish preparations served in catering establishments of Bombay revealed that there is no serious potential health hazard to the consumer. Pathogens like Salmonella and Clostridium per were found to be absent. Based on organoleptic, biochemical and bacteriological parameters the quality of fish curry was better than that of fish fry. Overall quality of samples from grade I establishments was better in comparison with grade II and III. However, a few samples of poor quality were also observed in grade I. Extraneous matter like hair and dead housefly were observed in a few samples from grade III indicating poor handling practices. The importance of good hygiene and sanitary practices in catering establishments is discussed.

Quality of certain ready-to-eat fish products of the domestic trade

Quality of 181 samples of ready-to-eat fish products comprising fried fish, fish curry and fish/prawn pickles collected from Cochin and Calicut were studied. Salmonella was absent in all the samples. V. cholerae was tested in the samples collected at Cochin and was absent in all the cases. Coliforms, E. coli, faecal streptococci and coagulase-positive staphylococci were present in some of the samples studied. The study indicated the necessity to improve the sanitary and hygienic conditions of the hotels engaged in the preparation of these products. The study further indicated that fried fish and fish curry shall not be served after 6 hours of their preparation. Added care is to be exercised in the selection of shrimps and fish for the preparation of pickles.

Incidence and low temperature survival of coagulase positive staphylococci in fishery products

Coagulase-positive staphylococci was found to be absent in all the frozen samples of lobsters, cuttle fish, cat fish, seer fish and red snapper examined. Coagulase-positive staphylococci were present in 38% of the cooked frozen shrimps and only 16% of the samples had staphylococci count more than 100/g. In the case of headless, peeled and deveined, peeled undeveined shrimps, the incidence of the organism was 6, 12 and 16% respectively. The study indicated that the incidence of coagulase-positive staphylococci is not a serious problem in frozen fishery products processed in this country. There was remarkable difference in the rate of destruction of coagulase-positive staphylococci in raw and cooked shrimps during freezing and frozen storage.

Effect of gamma radiation in combination with freezing on the microbiological changes in frozen shrimp Penaeus monodon

In this study gamma radiation (3, 6 and 9 kGy) in combination with low temperature (-20°C) were applied to retain the quality and shelf-life of shrimp, Penaeus monodon for a longer period. The quality was assessed by monitoring microbiological changes (TBC, TMC, TYC, TCC and Salmonella count) in irradiated and non-irradiated (control) samples. Among microbiological indicators of spoilage, total bacterial count (TBC) values for irradiated shrimps were found to be 1875, 1625 and 1525 cfugˉ¹ of sample at 3, 6 and 9 kGy respectively after 90 days whereas for non-irradiated samples it was found 2475 cfugˉ¹ of sample. Total moulds count (TMC) value for non-irradiated samples after 90 days were found 425 cfugˉ¹ sample whereas that for irradiated shrimps at 3, 6 and 9 kGy were found to be 275, 250 and 200 cfugˉ¹ sample respectively. Total yeast count (TYC) value for non-irradiated samples after 90 days were found 4125 cfugˉ¹ sample whereas that for irradiated shrimps at 3, 6 and 9 kGy were found to be 2850, 2150 and 1725 cfugˉ¹ sample respectively. Total coliform count and Salmonella count showed that those were absent during 90 days storage period. From this study, it was clear that gamma radiation in combination with low temperature showed shelf-life extension (90 days) in each dose of radiation used but during the use of 9 kGy radiation, Penaeus monodon showed best quality.

Genetic status of selected fish taxa in relation to conservation of genetic and species diversity in the Victoria and Kyoga Lake basins

Cichlids are known for their explosive radiation especially in the African Great Lakes marked with a high level of lake endemism. These fishes have been characterized mainly along trophic and habitat differences, by variation in morphological structures such as teeth and jaws and by differences in body shape and coloration. Cichlids are important as a microcosm of macroevolution. The explosive radiation, young evolutionary scale, and the isolation of groups characterized with high levels of endemism and presence of living fossils makes the group important for evolutionary and genetic studies. Lake Victoria region cichlids which are isolated and relatively more recent in evolution were the last to be appreciated in their diversity. Recently Ole Seehausen has found scores of rock fishes in Lake Victoria which were up to then thought to be absent from the Lake and only known to occur in Lakes Malawi and Tanganyika. Greenwood put together the species groups of Lake Victoria, and later in the early 1980's revised the classification of haplochromine species to reflect the phyletic origin and interrelationship of the various groups in Lake Victoria region. Melan Stiassny has been interested in early evolution of cichlids while the likes of Paul Fuerst and Lees Kaufman and Axel Meyer have been interested and are working to explain the speciation mechanisms responsible for the explosive radiation and evolution of cichlids. Locally S.B Wandera and his student Getrude Narnulemo are spearheading the biodiversity and taxonomic studies of cichlids in Lake Victoria region