1. KAUTIR (Kerala Agricultural University Theses Information and Retrieval)

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    Genetic characterization, controlled breeding and development of transgenic varieties of puntius denisonii (day, 1865).
    (Department of Aquaculture, College of Fisheries, Panangad, 2010) Manoj, C K; Mohanakumaran Nair, C
    Puntius denisonii, a beautiful ornamental fish indigenous to the Western Ghats, which has been indiscriminately exploited from the different rivers of Kerala has been recently declared to be vulnerable by the IUCN. The population structure and genetic diversity of P. denisonii has not yet been studied and documented. Many previous attempts to breed this fish in captivity have yielded negative results. The increasing demand for this fish to decorate aquariums worldwide could be satisfied only by developing controlled breeding techniques and larval rearing of its fry. In the present study, the present population structure of P. denisonii has been studied combining both phenotypic and genotypic techniques. Fishes were collected from Irrity, Chaliyar and Periyar rivers of Kerala. Truss network analysis was conducted and the size adjusted morphometric variables were subjected to Principal Component Analysis and Canonical Variance Analysis. Scatter diagram and Dendrogram was plotted using PCA and CVA loadings. The Irrity and the Chaliyar populations were grouped on the positive sector of the PC and CV component showing morphological similarities between the two populations while the Periyar population was placed in the negative sector of the component separated far from the other two. The PC scores were used to find out the variables showing maximum variation between fishes collected from different rivers. RAPD PCR was conducted after isolating DNA from the fins of different populations of P. denisonii. Universal random primers were screened and the primers that produced reproducible bands were selected. Popgene analysis of the binary data yielded the genetic structure of different populations of P. denisonii. Number and percentage of polymorphic loci, Nei's (1973) gene diversity, Shannon's Information index Lewontin (1972), Nei's Unbiased Measures of Genetic Identity and Genetic distance and Dendrogram Based Nei's (1978) Genetic distance using UPGMA --Modified from NEIGHBOR procedure of PHYLIP Version 3.5 were studied. The results obtained supports the truss analysis in that the Irrity and Chaliyar populations in Northern Kerala are genetically more similar while that of Periyar population in Central Kerala are distinct. P. denisonii was successfully induced bred under controlled conditions with synthetic hormone preparations Ovaprim and WOVA-FH. Stress during transport and handling was minimized and live feed was supplemented to enhance maturation of the broodstock. The whole developmental sequence starting from fertilized eggs to hatching was photographed and documented. It took 29-30 hours for the eggs to hatch at 280C. Rearing of fry was successfully accomplished under laboratory conditions. In an attempt to develop transgenic varieties of P. denisonii, pCMV-GFP was electroporated into newly fertilized eggs, maintained in hypoosmolar electroporation buffer. The electroporation parameters that yielded best results were 20V, 3 bursts at 1 second interval. Fin clips were taken from the transgenic individuals reared for a period of 6 weeks. Dot blot test was positive showing integration of the GFP gene in P. denisonii, eventhough expression was not detected under blue or UV light. The genetic and phenotypic data of P. denisonii populations in the present study will aid as a base line for formulating conservation procedures to protect the genetic diversity of wild ones. Stock identification studies are recommended for more concise information on each population. Moreover, the larval rearing and controlled breeding techniques along with the genetic diversity studies will help to design captive breeding programs and enhance the production of hatchery bred ones to meet increasing demand. Further research is recommended for generating transgenic lines with uniform GFP expression.
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    Growth and survival of penaeus monodon in monosex and mixed sex culture under laboratory condition
    (Department of Aquaculture, College of Fisheries, Panangad, 2008) Bajaniya Viralkumar Chhaganlal; Mohanakumaran Nair, C
    Sexual dimorphism is apparent in the black tiger shrimp, Penaeus monodon with females achieve larger size than the males. This character may be attributed to behavioral and/or physiological differences between the sexes. An experiment was developed to determine if there were advantages in rearing all female or all male P. monodon as opposed to mixed-sex populations. Juvenile shrimps (4.46±0.54 g) were collected from earthen pond and individually hand sexed and stocked in the circular cement tanks. Treatments all male, all female and mixed-sex were stocked @ 8 nos./tank. Each treatment had five replicates. The shrimps were offered commercial shrimp feed. The experiment was conducted for a period of 50 days. At harvest, all female shrimps had shown significantly higher growth than all male and mixed-sex treatment. Survival was not significantly different among treatments. FCR of all female was significantly lower than the all male and mixed-sex treatment. Result of the present study demonstrates a benefit to all female culture of P.monodon against the all male or mixed-sex culture. Thus culture of all female may be commercially more attractive to entrepreneurs. Although additional research is required to find a reliable and quick procedure for separation of the sexes or techniques for the production of all female populations.
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    Conditions for oxygen-packed transportation of penaeus indicus seed
    (Department of Aquaculture, College of Fisheries, Panangad, 1994) Geetha Rani Mani, V; Jayasree Vadhyar, K
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    Integrated culture of fish with micropropagated plants in a recirculatory system
    (Department of Aquaculture, College of Fisheries,Panangad, 2012) Navya, R; Devika Pillai
    An experiment was designed to study an integrated recirculatory sytem with micropropagated aquarium plants, fish and indigenous filter materials like coir, vetiver and bamboo as the filter media. The plants selected for the study were Bacopa caroliniana, Anubias minima, Aponogeton ulvaceus, Rotala rotundifolia and Nymphoides cristata. The first part of the work was to standardise the micropropagation techniques for the above said plants. Murashige and Skoog medium (half and full strength) was used as the basal medium for the establishment of cultures. The explants varied from nodal segments, rhizome buds, leaf petioles and lateral buds. Surface sterilization was carried out with a range of sterilants like mercuric chloride solution, ethyl alcohol, sodium hypochlorite solution etc. for varying durations and concentrations depending on the type of explant. Effect of growth regulators on explants were studied using auxin IAA and cytokinins, BA and Kn. A liquid culture media with 1.5mg l-1 BA and 0.1mg l-1 Kn concentrations was the best medium for Bacopa caroliniana. A combination of auxin cytokinin like 1.5 mg l-1 BA and 1.0 mg l-1 IAA in liquid culture was the best medium for Rotala rotundifolia. In Nymphoides cristata, hormone concentration of 1.0 mg l-1 each of BA and IAA in liquid culture gave the best results. In Anubias minima, a full MS solid medium with 6.0 mg l-1 of BA gave better results compared to lower levels of BA. In vitro trials for Aponogeton ulvaceus was not successful due to the exudation of phenolic extracts in all the treatments which eventually lead to the death of the tissues. Hardening success was 90 percent, 100 percent, 70 percent, 100 percent in the case of Anubias minima, Nymphoides cristata, Rotala rotundifolia and Bacopa caroliniana respectively. The micropropagated plants were incorporated in the recirculatory system along with fish and three different biofilter materials like coir, vetiver and bamboo splits. The study focused mainly on the filtering efficiency of the three filters based on the nitrification curves. The plants were included in the system to be a part of biofilter and their exclusive role in nitrification was not studied since this is a preliminary work. A nitification graph was plotted with the observed values of ammonia, nitrite and nitrate in the three different biofilter systems and compared with a control. It was inferred that coir fibres were the best of filter materials tried in nitrification followed by bamboo and vetiver. The control system took more time (45 days) in stabilizing ammonia levels due to lack of a substratum for growing nitrifying bacteria.
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    Extent of adoption of scientific practices in prawn farming
    (Department of Management Studies, College of Fisheries, Panangad, 1990) Sasikumar, P K; Pushkaran, P S
    This study was undertaken to probe into the present situation of prawn farming in Kerala. The study aimed at assessing the communication media used for the dissemination of scientific prawn farming practices, the communication media utilized by prawn farmers at awareness and adoption stages, extent of adoption of scientific practices, correlates of adoption behaviour and the reasons for non-adoption or partial adoption of scientific practices. The study was conducted in Ernakulam district among 100 prawn farmers randomly selected. The data were collected through personal interview using a structured and pre-tested interview schedule. Appropriate standard statistical tools were used for analysis and interpretation. The extent of adoption was measured using the adoption quotient formula. Twenty four characteristics of prawn farmers were tested to find their association with adoption behaviour. The socio-economic variables studied were age, education, experience , land possession training participation, institutional credit utilization and income from prawn farming. The situational characteristics included total farming area, area under selective stocking , salinity, distance from bar mouth, average depth at high tide, average depth at low tide and number of crops raised. Scientific orientation, economic motivation risk preference, marketing orientation, extent of awareness of scientific practices in prawn farming and rationality in decision making were the socio-psychological variables tested. The communication variables studied were utilization of personal localite sources, utilization of personal cosmopolite sources and utilization of mass media sources. The study revealed that the extension communication media were very extensively used for the dissemination of scientific prawn farming technology. The most important individual method employed was farm and home visits. Other methods frequently employed were lectures, film shows, group discussions, training programmes and demonstrations. The farmers utilized more of personal localite sources, followed by personal cosmopolite and mass media sources for awareness as well as adoption. The mean awareness index of prawn farmers was 64.00 with majority of the farmers falling under the category of medium awareness. The mean extent of adoption of scientific practices was worked out , and majority of the farmers came in the medium category based on extent of adoption. Of the 19 scientific practices selected for study, all the practices except ‘acclimation of seeds’, ‘maintenance of dissolved oxygen level in the pond’ ‘monitoring and control of PH, control of algal blooms and ‘need based control of disease and parasites’ were heard by over 50 percent of the respondents. Only three practices viz. strengthening of buds and deepening of channels, fixing or repairing of sluice gate, and stocking the pond with selected prawn seeds were heard by all the respondents. Only two practices namely ‘strengthening of bunds and deepening of channels’ and ‘fixing or repairing of sluice gate’ were found fully adopted by 50 or above 50 percent of respondents. Highest full adoption was observed for the practices ‘fixing or repairing of sluice gate’. There was no full adoptes for the practices ‘maintenance of dissolved oxygen level in the pond’ ‘need based water exchange’ and ‘need based control of disease and parasites’. Highest partial adoption was observed for the practice ‘need based water exchange’ followed by ‘removal of aquatic weeds’, supplementary feeding based on biomass’ and ‘strengthening of bunds’ and ‘deepening of channels’. The partial adopters of these practices were 99 percent , 92 percent, 57 percent and 49 percent respectively. Important reasons for non-adoption and partial adoption of the practices were lack of awareness, lack of knowledge and non-adoption of the practice ‘stocking the ponds with selected prawn seeds’. Among the 24 variables tested to find out association with extent of adoption, only nine showed significant influence on adoption behaviour. The characteristics of prawn farmers which were found significantly contributing to extent of adoption were training participation, land possession, institutional credit utilization, area under selective stocking, number of crops raised, extent of awareness of scientific practices in prawn farming, rationality in decision making, utilization of personal cosmopolite sources and utilization of mass media sources. Multiple regression model fitted with the above nine variables illustrated that these nine variables together explained 86.82 percent of variations in extent of adoption. Further, the step-wise regression analysis revealed that the best subset of variables in predicting the dependent variables were utilization of personal cosmopolite sources, utilization of mass media sources and area under selective stocking. These three variables together explained 86.48 percent of variations in adoptive behaviour. Of the nine variables subjected to path – analysis all the variables except awareness of scientific practices in prawn farming and rationality in decision making had positive path coefficients. The indirect influence of the variables on extent of adoption were mainly channeled through utilization of personal cosmopolite sources and area under selective stocking.
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    Molecular cloning characterisation and functional analysis of growth arrest specific gene 2 in Pearlspot (Etroplus suratensis)
    (Department of Plant Biotechnology, College of Agriculture, Vellayani, 2019) Amiya Thalakkattu; Pradeep, M A
    Etroplus suratensis is the State fish of Kerala which is a delicacy which has very high economic value. Water temperature is a very important factor which affect the growth of Pearlspot. There are many genes expressed at water temperature stress. The objective of the study was “Molecular cloning, characterization and functional analysis of Growth Arrest Specific gene 2 in Pearlspot (Etroplus suratensis)”. The study was carried out at the maricuture facility, CMFRI, Kochi. Growth arrest specific gene 2 is a component of the microfilament system which plays a major role in cell death and apoptosis. This was studied to be highly expressed at cell contact inhibition, serum starvation and temperature stress The growth arrest specific gene was amplified using specific primers. The GAS2 ORF was found to be a 1017 bp sequence which was translated into a 388 amino acid sequence. The predicted molecular weight of GAS2 was found to be 38.7 k.Da. and was found to have calponin homology domain and GAS2 as conserved domains. In the study, fish juveniles were exposed to 3 water temperatures 26˚C, 30˚C and 32˚C for 72 hours. The muscle, brain and liver samples were collected at 1 hour, 12 hour and 72 hour. The expression was studied in each tissue sample by real time PCR assay. The expression patterns at each temperature and each duration was compared with the expression observed in 26˚C samples maintained as controls. The GAS2 expression was found to decrease proportional to the duration of exposure in fishes exposed to 30˚C when compared to that in the control sample maintained at 26˚C. The trend was found to be reverse in fish exposed to 32˚C, the expression increased at a constant level compared to the 26˚C control. In both experiments the highest expression was observed in muscle tissue and the lowest expression was found in liver tissue. GAS2 was found to be a stress related gene which show variable expression in different water temperatures with least expression in a range of above 26˚C and below 32 ˚C.
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    Problems and prospects of seafood exporters in Ernakulam district, Kerala
    (College of Co-operation Banking and Management, Vellanikkara, 2017) Hari Prakash, A; Arularasan, G S
    Indian fisheries and aquaculture are important sectors of food production providing nutritional security to the food basket, contributing to the agricultural exports and engaging about fourteen million people in varied activities. With diverse resources ranging from deep seas to lakes in the mountains and more than 10 percent of the global biodiversity in terms of fish and shellfish species, the country has shown continuous and sustained growth in fish production since Independence. Constituting about 4.4 percent of the global fish production, the sector contributes to 1.07 percent of the GDP and 4.7 percent of the agricultural GDP. The total fish production of 6.4 million metric tonnes presently has nearly 55 percent contribution from the inland sector and nearly the same from culture fisheries. Paradigm shifts in terms of increasing contributions from inland sector and further from aquaculture are significant over the years, with high growth rates. The different facets of marine fisheries, coastal aquaculture, and fisheries are increasingly being diversified, contributing to food, health, economy, exports, employment and tourism of the country. The present chapter intends to summarise the findings in the foregoing comprehensive analysis. It seeks to make a set of suggestions while highlighting various aspects of production and exports, it also analyses factors contributing to the exports of seafood exports in Ernakulum District. This study makes an effort to bring out the problems and prospects of the marine fishery sector, it further makes some indication for future research.
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    Export performance of Indian Seafood Industry - a study on MPEDA Cochin
    (College of Co-operation Banking and Management, Vellanikkara, 2017) Deepthi Babu; Ranjit Kumar, E G
    Fish producing countries, apart from meeting the demand in domestic market, are exporting fish products to many countries to meet the demand in international market and also to earn foreign exchange. There are several items in the category of marine products which is meant for export of major destinations of the world. Export promotion is very essential for the development of Indian economy. Hence the government of India has been adopting various export promotional measures for the promotion and development of marine products. Export Promotion measures includ7e various policy decisions, schemes, concessions, incentives facilities offered to the exporters. The Marine Product Export Development Authority was constituted in 1972 at Cochin for the overall development of marine product industry and promoting the export of marine products. The authority is concerned with regulation and growth of marine products. Special emphasizes is laid on maintaining quality of marine products, processing, packing, storing, shipment, marketing etc. The authority conducts fairs and exhibitions and also takes part in international fairs. The authority advices central government on all matters related to seafood industry and its exports. On a thorough study conducted in the previous chapter, some facts were identified. As mentioned earlier, as there are number of items under the marine products meant for export to different destinations, analysis has been done for those items and the following details has been found out
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    Characterization of different stocks of Macrobrachium rosenbergii and development of genetically improved strain through selective breeding
    (Department of Aquaculture, College of Fisheries, Panangad, 2010) Shyla, G; Mohanakumaran Nair
    Giant freshwater prawn Macrobrachium rosenbergii (de Man, 1879) is an important species suitable for culture in inland and low saline coastal water bodies. Information on the genetic structure and variation among cultured species are essential for genetic approaches to optimize conservation strategies and breeding programmes for improving stocks. DNA based markers can be used to assess more precisely the genetic variations in the entire genome. Natural populations of M. rosenbergii inhabiting the rivers in different geographical areas of India show wide variation in morphological traits and economic characters. The present work envisages studying the genetic diversity of wild populations of M. rosenbergii collected from different parts of India through phenotypic characters and molecular marker studies. It also aims to develop a superior strain by combining the desirable characters through selective breeding. In this study genetic characterization of Andhra Pradesh (AP), Orissa (OR) and Kerala (KR) stocks of Macrobrachium rosenbergii were done with RAPD and Microstellite markers. Marker analysis showed variation between stocks and AP showed more genetic distance from OR and KR populations.Moreover KR stock from Achankoil River showed slight similarity with AP. Phenotypic trait analysis was done with three stocks. Egg diameter, larval hatch fecundity, larval rearing period, survival rate and larval length were estimated. Highest egg diameter and hatch fecundity were shown by OR and KR populations. AP showed minimum larval rearing period and maximum survival rate. Maximum larval length was for KR. Stress tolerance studies were conducted in V and X stage of M.rosenbergii larvae with temperature, salinity, formaldehyde and ammonia to estimate the relative differences in the ability of different populations to withstand stressed conditions. Among base population KR population showed highest tolerance towards temperature, salinity, formaldehyde and ammonia.Stage wise tolerance variations also found in all populations. X stage showed more tolerance to all stressors except ammonia. Comparison of other economically important parameters such as disease resistance, quality of flesh, percentage survival, growth rate, percentage morphotypes and head tail ratio were also done. Disease resistance was tested with white tail virus and bacteria (Enterococcus aerogenes) by challenge study. In both studies KR population exhibited better tolerance than other populations. Prophenoloxidase activity and total haemocyte count was also estimated in infected prawns to check the immune response. Here again KR showed higher activity and count. Flesh quality of three populations was estimated by carcass proximate analysis. In this study, no variation in body composition was shown by three stocks. Percentage survival rate and weight gain of three populations in cage were estimated. Maximum survival rate was found in AP and highest growth was found in KR stock. Analysis of percentage morphotypes of various populations showed the maximum OC for AP and SM for OR stock, with no significant variations in percentage BC and female prawns, head tail ratio, which was calculated to find out the yield of meat revealed the least ratio for KR. Large healthy prawns of the three stocks were selected from families showing better performance. Breeding experiment was conducted to produce six crosses viz. Andhra Pradesh (male)×Orissa (female) APOR, Orissa (male) × Andhra Pradesh (female) ORAP, Andhra Pradesh (male) × Kerala (female) APKR, Kerala (male) × Andhra Pradesh (female) KRAP, Orissa (male) × Kerala (female) ORKR, Kerala (male) × Orissa (female) KROR. Different phenotypic characters and economically important traits of F1 generations of hybrids were also studied. KROR showed better egg diameter, hatch fecundity, larval survival rate and larval length. But larval rearing period was minimum for APKR. KROR showed resistance to viral and bacterial diseases, which was similar to that of KR and better than other hybrids. In cage culture APOR showed better survival rate, while growth rate was significantly higher for KROR, which was more than that of base populations. Analysis of percentage morphotypes showed a similar pattern as that of base populations. Lower head -tail weight ratio was shown by KROR, which was lower than that of KR. Estimation and comparison of heritability of weight of three better performing hybrids were done. From the data it was found that maximum heritability of weight was for KROR (.75) followed by APKR (.161) and APKR exhibited no heritability.
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    Quantification of ammonia excretion by selected five varieties of freshwater ornamental fishes
    (Department of Aquaculture, College of Fisheries, Panangad., 2006) Senthamilselvi, A; Mohan, M V
    Ammonia 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 aquarium