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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 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.ThesisItem Open Access Quantification of ammonia excretion by selected five varieties of freshwater ornamental fishes(Department of Aquaculture, College of Fisheries, Panangad., 2006) Senthamilselvi, A; KAU; Mohan, M VAmmonia excretion of five species of freshwater ornamental fishes, platy (Xiphophorus maculatus), swordtail (Xiphophorus helleri), angelfish (Pterophyllum scalare), goldfish (Carassius auratus) and blue gourami (Trichogaster trichopterus). Fishes acclimated for two weeks were incubated for a specific period in closed containers and the ammonia excretion rates were determined. Ammonia was determined using phenol hypochlorite method. Regression analysis of ammonia excretion rate and weight showed that ammonia excretion rate increased with body weight. The regression coefficient of the relationship was 0.4320 in platy, 0.7534 in swordtail, 0.4851 in angelfish, 0.6309 in goldfish and 0.6518 in blue gourami. The weight specific ammonia excretion rate decreased with bodyweight and the slope of the weight specific ammonia excretion rate – weight relationship was - 0.5680 in platy, - 0.2466 in swordtail, - 0.5149 in angelfish, - 0.3691 in goldfish and - 0.3482 in blue gourami. The regression coefficient of total length- weight and standard length- weight relationship are 3.1031 and 3.0565 for platy, 3.1512 and 3.1454 in swordtail, 3.0331 and 2.9656 in angelfish, 2.6191 and 3.0328 in goldfish and 2.9721 and 3.0011 for blue gourami, respectively. The regression coefficients were significantly different from 3 in both the relationships. The weight specific ammonia excretion rate ranged from 0.0032 to 0.0640 g NH3-N/mg/h for platy, 0.0028 to 0.0140 g NH3-N/mg/h for swordtail, 0.0033 to 0.1309 g NH3-N/mg/h for angelfish, 0.0043 to 0.0525 g NH3-N/mg/h for goldfish and 0.0091 to 0.0394 g NH3-N/mg/h for blue gourami. Ammonia excretion rate and weight specific ammonia excretion rate were highest for blue gourami, followed by goldfish, angelfish, swordtail and platy but the weight specific ammonia excretion rate was highest in platy than swordtail for the smaller size group. Quantification of ammonia excretion for standard weight and length facilitates prediction of ammonia build up in a freshwater aquariumThesisItem Open Access Abundance and distribution of the nonconventional deep-sea finfish resources off the south-west coast of India (lat.7-10N)(Department of Fishery Biology, College of Fisheries, Panangad, 2005) Sajeevan, M K; KAU; Rajasekharan Nair, JMost of the conventional fishery resources of the continental shelves of the Indian EEZ are either optimally exploited or over exploited. Exploitation of the unexploited nonconventional finfishes will be a solution to meet the growing demand for fish in the country. The present study based on the exploratory fishing data of M.F.V. Matsya Varshini during the period of February 2004 to April 2005 indicates the presence of nonconventional finfish resources along the deeper waters (100-500 m) off the south west coast of India (70-100N lat.). 97 species belonging to 16 orders, 51 families, and 78 genera recorded during the study points to the rich diversity of nonconventional finfishes in the study area. Nonconventional finfishes formed 72% of the trawl catches obtained during the period under study. Distribution pattern and abundance of the nine species/species-groups are presented and discussed. Area-wise 70-80N lat. (200-500 m depth zone) has been found to be more productive and the abundance has shown a decreasing trend towards the northern latitudes. Results of the study confirm that bathymetric difference is the key factor for the distribution and abundance of deep-sea finfishes. Depth wise, the 200-300 m zone has been found to be more productive with a relative abundance of 1829.7 kg.h-1 of deep-sea finfishes. Trichiurus auriga with a relative abundance of 146.78 kg.h-1 dominated among finfishes, followed by Psenopsis cyanea with an average relative abundance of 144.38 kg.h-1. Existence of seasonal variation and difference of habits of the nonconventional finfishes have been observed during the study. Results of the length frequency studies carried out for seven important nonconventional finfish species are discussed. A standing stock of 98442.17 tonnes estimated for the nonconventional finfishes from the study area makes them a potential resource for commercial exploitation. Biomasses of the 9 species/species-groups of nonconventional finfishes estimated separately are also presented. Need of an organized survey of nonconventional deep sea finfishes covering the entire Indian EEZ by using different types of gears has been highlighted.ThesisItem Open Access Influence of a putative male pheromone on ovarian maturation and ovulation in the freshwater prawn Macrobacterium rosenbergii (de man, 1879)(Department of Fishery Hydrography, College of Fisheries, Panangad, 2005) Smitha Ramakant, Gawade; KAU; Jose, T MDiscovery of a male primer sex pheromone with a specific stimulatory effect on ovarian maturation and ovulation in the small sized freshwater shrimp Paratya compressa and the prawns Macrobrachium kistnensis and M. idella is considered very significant. In this context, it was the objective of the present study to investigate this aspect in the commercially important giant freshwater prawn Macrobrachium rosenbergii (de Man 1879). Two sets of experiments were carried out using sexually mature females and blue claw males collected from wild. The first experiment (to study the effect of male deprivation on ovarian maturation) had two groups of females. Group I had isolated females (without males) and group II had females cohabiting with males. Ovarian maturation was monitored daily for 60 days. Maturity stages and the number of berried females were noted and average spawning frequency calculated. There was no difference in the percentage of berried females and average spawning frequency between the two groups and hence no evidence for blocked ovarian maturation in isolated females due to the lack of a male factor. The second experiment was done to delineate the role of visual and/or chemical cues on ovarian maturation in M. rosenbergii. Specially designed glass aquaria were used which had three compartments for three groups of females. Group I females were isolated and received only visual signals and no chemical cues from the males. Group II females were cohabiting with males. Group III females were also isolated from males but received only chemical cues from males through a common water circulation. The same parameters as in the first experiment were monitored for 60 days and no significant difference found between the three groups. Histological study also showed normal maturation. The conclusion is that there is no evidence for an ovary stimulating pheromone in M rosenbergii thus adding one more feature to the distinctiveness of this species.ThesisItem Open Access Infestation of isopode parasites on prawns of the genus Macrobrachium Bate (Palaemonidae) of Cochin region(Department of Fishery Biology, College of Fisheries, Panangad, 2004) Regina Jasmine, M; KAU; Jayachandran, K VThe major objective of the research work is to study the taxonomy, species diversity, host specificity, intensity of infestation, length - weight relationship and reproductive biology of bopyrid parasite infesting the genus Macrobrachium Bate, 1868 of the Cochin region. Collections were taken from 3 stations Perumbavoor (Periyar River) and Panangad (Vembanad lake) for a period of 13 months (July 2002 to July 2003) and Champakkara (Vembanad lake) for a period of one year (October 2003 to September 2004). The study revealed that of the five species of Macrobrachium inhabiting water bodies of Cochin region, only two species were found infested with bopyrids. Macrobrachium idella was infested with Palaegyge alcocki whereas M. scabriculum with a new variety, P. alcocki var. novo cochinensis. This shows that bopyrid infestation is species specific. Diagnostic characters of both the parasite species are given in the text. Regarding the intensity of infestation, prawns from the Perumbavoor region of Periyar River had maximum infestation in comparison with other regions (Panangad and Champakkara). The infestation during different months also revealed the same trend. It indicates that infestation is more at the freshwater region than at the estuarine region. Relationships between length and weight of infested M. idella, P. alcocki separated from the host, total length of host and parasite, total length of male and female parasite, carapace length of the host and total length of male as well as female parasite are all statistically significant. . The study has brought out the ways of association of male and female parasites as well as attachment of female parasite to the host. Mature female parasite has been distinguished from the immature. Fecundity studies revealed that the number of eggs produced by the parasite ranges from 8148 (1 cm total length, 0.9 cm total width, 0.12 g total weight) to 29,683 (1.2 cm total length, 1.0 cm total width, 0.168 g total weight). Number of ova per milligram body weight ranged from 67.9 to 185.518 (126.709 average). Relationships between fecundity and total length, total weight, total width and total weight of brood of the parasite are all significant. The chapter on reproductive biology reveals important observations on marsupial brooding, ovulation, embryonic development and incubation, hatching and epicaridea stage of P. alcocki. The last chapter is on the effect of parasitism on the host. Here the aggressive behaviour of infested host, parasitic castration, degeneration of gills and secondary infections are dealt with in some detail.ThesisItem Open Access Temporal changes in the weather elements at Panangad region and their influence on the hydrography of a pond(Department of Fishery Hydrography, College of Fisheries, Panangad, 2004) Pronob Das; KAU; Raman, N NThe present study was undertaken with a view to finding out the seasonal and diurnal changes of weather elements at Panangad region, seasonal and diurnal changes in the hydrographic parameters of a freshwater pond and finally to understand the possible influence of weather elements on hydrographic conditions of a pond during the four seasons viz. southwest monsoon season (June-September), post monsoon season (October-November), northeast monsoon season (December-February) and pre monsoon season (March-April) at the College of fisheries, Panangad, Cochin. Meteorological data were collected at 03 UTC (0830 IST) and 12 UTC (1730 IST) daily during the period from June 2003 to April 2004. Water samples were collected from a pond every fortnightly to analyse hydrographical parameters. To study the diurnal variation, 24-hour observation were taken at an interval of 3 hrs, once for each season. Meteorological observation includes air temperature, maximum temperature, minimum temperature, total rainfall, relative humidity, cloudiness, wind speed and direction. Hydrographic parameters like water temperature, pH, transparency, water level, total alkalinity, primary productivity, dissolved oxygen, nitrate, nitrite, phosphate and silicate were estimated. There was a considerable seasonal variation in water qualities. The surface temperature closely followed the air temperature and exhibits a clear double oscillation. Low pH values confined to the southwest monsoon period were due to heavy rainfall. pH showed a positive relation with air temperature. At higher temperature evaporation was more and water level decreased, which leads to the higher concentration of plankton bloom and low level of transparency. Presence of nutrient elements in optimum concentration and there by production of phytoplankton and algal bloom may be the possible reason for the high productivity during the northeast and pre monsoon periods. The low values of primary production during southwest monsoon period (June to September) and in October might be due to cloudy conditions before and during the sampling, which reduced light intensity, and along with incessant rains cut down production. The high concentration of alkalinity during pre monsoon may be due to decrease in water level due to evaporation. The effect of rainfall in decreasing bicarbonates is well known. Dissolved oxygen was at the highest level in ponds during colder months and was due to low temperature and intense photosynthetic activities. Subsequent fall of dissolved oxygen in pre monsoon period is attributed to the death and decay of plankton and presence of other organic matter. The plankton population in the pond was highest during the month of December/January to April, coinciding with the higher concentration of alkalinity and nutrients. Diurnal variations in water temperature, pH, dissolved oxygen, alkalinity and primary productivity were well marked. Among nutrients phosphate, nitrate and nitrite did not show any specific pattern, where as silicate concentration showed well-marked short-term variation in all seasons. Weather elements showed significant relationship with many hydrographical parameters and the variations might be due to the combined effects of all those factors. The influence may be direct or indirect. Among the weather elements the influence of air temperature and rainfall was most prominent. The seasonal and diurnal changes in weather elements were equally important for the changes in hydrographical parameters. Shallow water bodies quickly react to the changes in weather elements.ThesisItem Open Access Quality and shelf life of fillets and cubes of a marine perch (Lethrinus lentjan (Lacepede,1802)) smoked by a mechanical smoker(Department of Processing Technology, College of Fisheries, Panangad, 2004) Sindhu, S; KAU; Krishnakumar, SA study was undertaken for the preparation of cubes and fillets from a marine perch King emperor or Pig face bream (Lethrinus lentjan, (Lacepede), 1802)). A method was standardised for preparation of smoked cubes and fillets. The parameters standardised were brining conditions, draining conditions, pre-drying conditions, smoking temperature and smoking time. The various brining conditions studied were brine concentrations of 10 %, 15 % and 20 % for brining times 15 min, 30 min and 45 min each. The various draining conditions studied were draining at room temperature and refrigerated conditions for periods of 15 min, 30 nun and 45 min. The pre drying conditions studied were pre-drying in tray drier and smoking kiln at 500e for 15 min, 30 min and 60 min. The smoking conditions studied were smoking at temperatures of so'c, 90oe, 1 oo'r: for 1 hr, 2 hrs and 3 hrs each. Salt content, moisture content and phenol content of the samples were analysed based on parameters studied in addition to sensory evaluation. Based on the test results the following treatments were selected viz., brine concentration of 10 % and brining time 15 min, draining under refrigerated condition for 30 min, pre-drying in tray drier for 30 min at 500e and smoking temperature of 800e for a period of 3 hrs. Smoked cubes and fillets were prepared using the standardised procedure and subjected to storage studies for a period of four months under different packing conditions viz., (i) smoked cubes and fillets packed in PE bags (ii) smoked cubes and fillets dried at 500e for 1 hr and then packed in PE bags and (iii) smoked tubes and fillets dried at 500e for I hr and then packed in paper bags. Quality changes during the storage period were monitored 15 days time intervals for parameters viz., moisture content, per cent free fatty acids, thio barbituric acid value, total plate count, total fungal count and sensory evaluation. Samples packed in paper bags remained acceptable only up to 60 days of storage and samples packed in PE bags were acceptable upto 90 days of storage.