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ThesisItem Open Access Reproductive biology of macrobrachium canarae ( tiwari, 1958 ) (decapoda, palaemonidae)(Department of Fishery Biology, College of Fisheries, Panangad, 2008) Sreedevi, K H; KAU; Jayachandran, K VThe aim of this project is to introduce the freshwater prawn Macrobrachium canarae (Tiwari, 1958) as a candidate species in a community aquarium. The orange red shining spot on the second cheliped where the movable finger joins with palm makes it appealing in the aesthetic sense. This species is found to breed in captivity also. For the effective management of the prawn in the aquarium, a thorough knowledge on the various aspects of its reproductive biology is a prerequisite. The various aspects of reproductive biology dealt with are 1. Taxonomy 2. Sexual dimorphism 3. Breeding dress 4. Maturity stages and ovarian development 5. Fecundity 6. Moulting Since the species do not exhibit sexual dimorphism in size, it is difficult to identify male and female. The difference in colour of antennular flagellum between sexes becomes useful especially when they are bred in captivity. The data on maturity stages and also the time of ovarian development finds its use especially in the aquarium rearing. The fecundity studies gives an idea of the number of offsprings which could be produced from a single brood .ThesisItem Open Access Ovararian maturation, breeding and early embryonic development of an indigenous ornamental cyprinid of the western ghats - chela fasciata silas(Department of Fishery Biology, College of Fisheries, Panangad, 2008) Indira, Divipala; KAU; Anna Mercy, T VChela fasciata is an indigenous ornamental cyprinid endemic to the Western Ghats of Kerala. It inhabits the riffle zones of River Bharathapuzha at Thootha. A total of 144 fishes (94 females and 50 males) ranging in size from 26.0 to 82.0 mm were collected from the wild and used for the study of reproductive biology. The gonads were quantified into six maturity stages based on external morphology as immature virgin, maturing virgin, early ripening, late ripening, ripe and partially spent. Studies on oocyte distribution of the six stages of maturity were done to understand the maturation of ova in the ovary. The ovaries of Chela fasciata showed asynchronous oocyte development. The oocyte development was classified into nine different oogenic stages namely, chromatin nucleolus stage, early perinucleolus stage, late perinucleolus stage, yolk vesicle stage, primary yolk stage, secondary yolk stage, tertiary yolk stage, migratory nucleus stage and mature oocyte). The first mature females appeared in the length group of 40 – 45 mm and males in the group of 25 – 30 mm. The size at first maturity for female was found to be at 45.75 mm TL (45 – 50 mm) and for males at 36.25 mm TL (35 – 40 mm). All the females were mature by 60.00 mm TL and the males by 45.00 mm TL. Based on the ova diameter frequency study of the ripe ovary, Chela fasciata was found to be a multiple spawner, with a protracted spawning season, the individuals spawning intermittently. Absolute fecundity of the fishes ranged from 2669 to 4437 in fishes of size range 49.5 mm to 82 mm TL. The number and size of eggs were found to be directly proportional to the size and age of the fish. Fecundity showed a positive linear relationship (5% level of significance) with the length and weight of both the fish and ovary. The embryonic development studies showed that the cleavage stage of the egg lasted for about 2 hrs 10 min., post fertilization. The inside egg embryo stage had lasted for 21 hrs, post fertilization. The eggs hatched at the end of 21 hrs, and the embryos emerged tail first. Pigmented eye was seen in one-day-old free embryo. Free embryo stage lasted for three days post fertilization. By the end of third day, the mouth developed, the yolk sac was empty and the exogenous feeding started, the free embryo entering the larval period. A complete understanding of basic reproductive biology of this fish will definitely help in the commercial production under captivity for the domestic and export market of this indigenous ornamental fish.ThesisItem Open Access Temporal variation in the hydrography and biodiversity of the Cochin backwaters of Puduveypu region.(Department of Fishery Hydrography, College of Fisheries, Panangad, 2011) Trinayan Deb, Sarmah; KAU; Raman, N NThe study was carried out to find out the temporal variation in the hydrography of the Cochin backwaterS of Puduveypu region and to find out the richness of the biodiversity of the area. The study was conducted from April, 2010 to Apil, 2011. The present study was carried out to find out the temporal variation in the hydrography of the Cochin backwater of Puduveypu region and to find out the richness of the biodiversity of the area. The value of salinity in the backwaters of Puduveypu showed a wide fluctuation. The maximum value was recorded in the second half of January. The salinity showed considerable reduction during the period of March-April, 2011 due to Premonsoon showers. . Water temperature showed peak values during pre-monsoon period and with the onset of monsoon the value decreased. High pH was observed during the monsoon season while low values were observed during N.E. monsoon and pre-monsoon period. Alkalinity showed an increasing trend during the pre-monsoon, post monsoon and N.E. monsoon seasons but a decreasing trend was observed during monsoon season. Total hardness ranged between 22.22 mg CaCO3/l and 710.01 mg CaCO3/l. Dissolved oxygen showed high values during monsoon and post monsoon period. During the N.E. monsoon period the dissolved oxygen showed a decreasing pattern and reached a minimum of 2.1mg/l in the second half of February. The higher values of nitrate-N were observed during post monsoon and monsoon season. Seasonal variation of nitrite 133 was not that much pronounced. The phosphate value ranged between 2.2 μg at/l and 5.8 μg at/l during the study period. The maximum value of silicate-Si was recorded during the last phase of the monsoon. Turbidity ranged between 11.11 NTU and 40.4 NTU. It showed a negative correlation with transparency. Transparency value of the study region falls within a range of 30 cm. to 47 cm. Primary productions showed a wide range from 32 mgC/m3/day to 3707 mgC/m3/day. The highest value of chlorophyll was observed during the second half of July and the minimum value was observed during the second half of October. The sediment pH value ranged between 7.02 and 8.3 with an average of 7.78. The analysis revealed that sediment of the Puduveypu region contains maximum sand followed by silt and clay. Mangrove species like Rhizophora mucronata, Rhizophora apiculata, Rhizophora conjugate, Brugiuera cylindrical, Brugiuera gymnorhiza, Sonerasia caseolaris, Sonerasia alba, Avicennia officianalis, Exocearia agallocha, Acanthus ilicifolius, Clerodenterum innerme, Premma latifolia, and Acrostichum aureum were found in the study area. , Avicennia officianalis contribute 70% of the total population of mangrove. Penaeus monodon, P. indicus, Metapenaeus dobsonii, M. monoceros, Feneropenaeus indicus, Penaeus semisulcatus, Macrobrachium equidens, M. idella have been identified from the study area. Crabs in the study area include Scylla serrata, Scylla tranquebarica, Thalamita creneta, Charybdis annulata, Sesarma quadratum, Uca vocans. Bivalves includes Lamellidens 134 sp., Villorita Sp. and Cirriped in the study region include Balanus. 36 species of finfishes were collected during the study period. The fishes can be categorized into 10 order and 26 families.ThesisItem Open Access Development of Malaysian Type Fish Crackers From Nemipterus Japonicus (BLOCH)(Department of Processing Technology,College of Fisheries, Panangad, 2001) Venugopal, Dubakula; KAU; Sajan, GeorgeA study was undertaken for the preparation of fish crackers using a low cost fish, threadfm bream (Nemipterus japonicus, Bloch). A method was standardised for making crackers based on that generally followed in Malaysia. Fish meat was mixed with various food additives such as starch, salt, sugar, monosodium glutamate, colour and water, and stuffed into high-density polyethylene casings as rolls, cooked, cooled, sliced and dried.ThesisItem Open Access Studies on the electrophoretic pattern of Fish/ Shellfish proteins subjected to frozen storage(Department of Processing Technology,College of Fisheries, Panangad, 2000) Bomy, Chummar; KAU; Nambudiri, D DFreezing considered as an excellent process for preserving the quality of fish for longer periods. But freezing may affect various flesh components, especially the proteins. Sarcoplasmic proteins play a major role in species identification of fish and fishery products. While myofibrillar proteins play a major role in the jellying properties of surimi and surimi based products. The changes to these groups of proteins due to freezing and frozen storage have received much attention. Four species Megalaspis cordyla, Labeo rohita, Penaeus indicus and Parapenaeopsis styli/era were used for the frozen storage study. Samples were stored for 90 days at -18°C and samples were collected at 15 day. intervals and Salt Soluble Nitrogen (SSN), Water Soluble Nitrogen (WSN) and Non-Protein Nitrogen (NPN) content were determined. Electrophoretic pattern of both Salt Soluble Proteins (SSP) and Water Soluble Proteins (WSP) of frozen stored sample were compared with that of the fresh sample.ThesisItem Open Access High density rearing of Labeo Rohita (Hamilton) spown indoors using different feeds(Department of Aquaculture, College of Fisheries, Panangad, 1998) Dinesh, K; KAU; Mohankumaran, Nair CThree day old rohu spawn was reared in indoor tanks with eight different feeds The diets tried were newly hatched Artemia nauplii, size graded Moina micrura, formulated feed, Artemia nauplii + formulated feed, Moina micura+ formulated feed, first 3 days Artemia nauplii and formulated feed later on, first 3 days Moina micrura and formulated feed later on and mixed zooplankton + ricebran and GOC in I: I ratio (conventional method).ThesisItem Open Access Studies on drying of fish using a BARC - TYPE solar dryer.(Department of Processing Technology,College of Fisheries, Panangad, 2011) Vimaladevi, S; KAU; Sajan, GeorgeA study was conducted with the aim of evaluating the drying efficiency of a newly designed solar dryer (modified BARC type) in comparison with conventional sun drying. The materials used for drying were beheaded prawn (Metapenaeus dobsoni) and salted fish (Cynoglossus macrostomus). Rate of drying was found to be influenced by the atmospheric temperature and humidity, either using dryer (test or by sun drying (control). In the case of prawn, the drying period was 7h by dryer compared to control which took about 10h whereas in the case of fish it was only 7h compared to control which took about 9h. Various parameters such as moisture content, water activity, TPC, TFC, TVBN content and PV, during drying were monitored. The quality variations in prawn or fish were significantly lower when dried using the solar dryer compared to direct sun drying. Sensory evaluation based on colour, odour, texture and taste, also proved that the solar dried samples were of superior quality compared to control. Sorption isotherm for test and control did not vary much in shape for both prawn and fish. This indicates that the effect of the type of drying on the bound water of the products. For conducting storage studies the dried prawn and dry salted fish, both test and control, were packed in low permeable polypropylene- polyamide bags and stored at room temperature for about 80 days. Quality parameters, viz., moisture content and water activity, TPC, TFC, TVBN content, PV and sensory evaluation based on colour, odour, taste and texture were evaluated during storage. Both test and control samples remained acceptable throughout the storage period. However, the quality of prawn or fish dried in solar dryer was found to be superior compared to their respective sun dried control samples. The additional cost was only Rs 2.40/ kg for dried prawn and Rs 2.00/ kg for dry salted fish. The equipment is recommended for small scale production of dried products.ThesisItem Open Access Studies on electrophoretic identification of fish species used in surimi(products) and their quality evaluation(Department of processing technology, College of fisheries, Panangad, 2008) Mathivanan, A; Nambudiri, D.DSDS-PAGE pattern of water soluble proteins and salt soluble proteins of raw fillets, surimi, sausage and different combinations (1:1; 3:1; 1:3; and 4:1) of surimi mixtures; sausage mixtures from the two species of fish, threadfin bream (Nemipterus japonicus), and bulls-eye (Priacanthus hamrur) were studied to see that whether these pattern are useful in identifying the species used for the preparation of surimi and sausage; and their quality evaluation. SDS-PAGE gave the effective species-specific pattern of raw fillets, surimi, sausage and surimi mixtures; sausage mixtures of extract of water and salt soluble proteins of threadfin bream and bulls-eye separately. Threadfin bream and bulls-eye were effectively identified by using their SDS-PAGE pattern of extract of water soluble proteins and salt soluble proteins separately. Threadfin bream and bulls-eye surimi and sausage were also effectively identified by comparing their SDS-PAGE pattern with species-specific SDS-PAGE pattern in their extract of water soluble proteins and salt soluble proteins separately. The SDS-PAGE pattern of water soluble proteins and salt soluble proteins were shown in this study to be effective in distinguishing the species specificity between threadfin bream and bulls-eye of raw fish fillets, surimi and sausage samples. Adultered/substituted species in the different mixture were identified by comparing their mixture SDS-PAGE pattern with species-specific SDS-PAGE pattern in their extract of water soluble proteins and salt soluble proteins separately. Different mixtures species-specific SDS-PAGE protein patterns can be used with reservation to detect/differentiate the adulteration/substitution in the fish mixtures, surimi and sausage when these two species mixed with the combinations of 1:1; 3:1; 1:3 and 4:1 ratios. The quality evaluation study showed that surimi, sausage and surimi mixtures; sausage mixtures of threadfin bream and bulls-eye used for the experiment were of good quality.ThesisItem Open Access Microbial risk assessment and process standardization for cook-chill fish and partially processed value added fish(Department of processing technology, College of fisheries, Panangad, 2007) Anju; KAU; Namboodiri, D DA study was undertaken for the preparation of cook-chill fish from Selar crumenophthalmus and partially processed value added fish from Oreochromis mossambicus and their microbial risk analysis. Standardization of processing technique for both products was done. Parameters standardized were brining conditions and blanching conditions for cook-chill fish. Standardization of brining condition was carried out for partially processed value added fish. Various brining conditions studied were brine concentrations of 3%, 5%, 6% for 5min, 10min, 15min and blanching at 75oC for 60sec, 90sec, and 120sec for cook-chill fish. In the case of partially processed value added fish brining concentrations of 1%, 2%, 3% for 5min, 10min, and 15min. Salt content and sensory evaluation were carried out, in case of cook-chill fish to select best blanching time. TPC values were determined. Based on the results the following treatments were selected. In the case of cook-chill fish brine concentration of 5% for 10min and blanching at 75oC for 90sec were selected. For partially processed value added fish the brine concentration of 2% for 10min was selected. Both products were packed and chill stored using ice at 4oC. Cook-chill fish was packed in polyethylene and heat sealed. Partially processed value added fish was vacuum packed in 12 polyester laminated with polyethylene 200 gauge. Control was used for comparative study. Control in the case of cook-chill fish (Selar crumenophthalmus) was fish fillets stored without any brining, cooking treatments. For partially processed value added fish (Oreochromis mossambicus), control was not given any brine treatment, was packed in polyethylene and heat sealed using electric heat sealer. During storage TMA, TVB-N, TPC and test for specific microorganisms were carried out. Results of quality parameters showed a greater shelf life of five days for test samples compared to the control in both the products.