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ThesisItem Open Access Molecular taxonomy of selected species of macrobrachium bate, 1868 (DECAPODA, PALAEMONIDAE) of Kerala waters(Department of Fishery Biology, College of Fisheries, Panangad, 2011) Jayaraj, G; KAU; Jayachandran, K VFreshwater prawns of the genus Macrobrachium are a conspicuous and important prawn constitute one of the most diverse, abundant and widespread crustacean genera. They are distributed in different water bodies of the tropical and subtropical regions of the world and comprises over 200 described species (Jayachandran, 2001). The palaenonids have taxonomically difficult groups because they appear to be morphologically higher conservative and also greater confusion among the evolutionary status. The present study was carried out both on morphological and molecular data to investigate the confirmation of species status and finding phylogenetic relationship of selected species of Macrobrachium in kerala waters. The species of M. canarae, M. idella, M. latimanus and M. scabriculum were collected from different water bodies of kerala, such as hill streams, rivers and brackish water. The four species inhabit varied habitats: M. latimanus is a hill stream prawn; M. canarae inhabits valleys without migration; M. idella and M. scabriculum inhabits lower stretches of river with estuarine migrations. These species were accurately identified based on morphology of earlier literature done by Jayachandran, 2001 and it shows variations within the individuals of M. idella. The use of DNA based methods to infer phylogenetic relationship can potentially overcome some of the difficulties encountered through the use of morphological characters. In molecular part, 16S rRNA and COI genes of mitochondrial DNA were analysed. Sequences of 16S rRNA and COI were obtained and submitted to NCBI. Based on sequence information, M. canarae shows few minor variations within the individuals. M. idella is shows significant variations within the two types of individuals. M. latimanus is shows separate clades of other country species. M. scabriculum is also shows significant variation with NCBI sequence of M. scabriculum. Phylogenetic relationship is clearly shows two types of M. idella based on NJ and MP tree. Hence, both morphological and molecular data is very effective for finding species variants and phylogeny.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 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 Modeling crop water stress index (cwsi) in tree seedlings(College of Forestry, Vellanikkara, 2011) Sneha, C; KAU; Santhosh, Kumar A VThe research work on 'Modeling crop water stress index (CWSl) in tree seedlings' was taken up at Department of Tree Physiology and Breeding, College of Forestry during April 2010 to March 2011. The objective of the study was to detect water stress in seedlings of teak and mahogany with the help of infrared thermometry by developing CWSI. Six month old seedlings were provided with four different irrigation treatments- irrigation at lW/ET=l, 0.6 and 0.3 on weekly interval and a control treatment was maintained with no irrigation (IWIET=O). Plant canopy temperature was recorded on daily basis from each treatment using a hand held infrared therinometer (HTC lR-8811). The non-water-stressed baseline (NWSB), obtained from canopy air temperature deficit and vapour pressure deficit (VPD) in the well watered treatment (irrigation at 1.0 lW/ET) and water stressed baseline obtained from non irrigated lW/ET=O. For teak the lower baseline was determined as CATD = -1.01VPD+2.8 and the upper baseline equation was CATD = -O.OSVPD+S.1. For mahogany, lower baseline equation was CATD = -0.2SVPD-2.9 and the upper baseline equation was CATD = -0.01 VPD+6.1. CWSl was calculated for each treatment using these baseline equations. The CWSl responded to irrigation events along the whole season, and clearly detected mild water stress, suggesting extreme sensitivity to variations in plant water status. Non irrigated lW IET=O showed a greater value for CWSl for all the time followed by treatment provided with irrigation at lW IET=O.3 while the treatments with higher irrigation levels (IWIET= 1 and 0.6) had lower CWSl values. It indicates that there is an increase in CWSl with time as available water in the soil decreased. It has been observed during the study that teak seedlings are more susceptible to water stress than mahogany. Observation on canopy air temperature deficit showed that, teak seedlings from all treatments maintained a constant canopy air temperature deficit all over the week. In mahogany, lWIET=l and lWIET=O maintained a constant canopy air temperature deficit, whereas, lW/ET=0.6 and lW/ET=0.3 showed a slow increase prior to the next irrigation. This reveals a relatively higher water use of teak seedlings when compared to mahogany. Well watered mahogany seedlings showed higher crude protein content compared to other treatments indicating a significant reduction in photosynthesis occurred during water stress. But for teak seedlings no difference was observed among different treatments. Chlorophyll content was found to be decreasing due to water stress in both species. Teak seedlings showed significant reduction in total height, collar diameter, number of leaves, shoot weight, root weight, shoot root length ratio and relative growth rate on the course of stress treatment whereas root length was increasing. Shoot root biomass ratio was found to be least affected due to different levels of irrigation treatment. In the case of mahogany, collar diameter, shoot root length ratio and relative growth rate were found to be decreasing due to water stress. Root length was found to be increasing due to water stress. Plants were able to maintain total height, total leaf number, shoot weight, root weight and shoot root biomass ratio unaffected even under irrigation at IWIET=O.3 also. Comparison on growth characteristics and physiological parameters of two species- teak and mahogany by providing different levels of irrigation revealed that mahogany uses water more efficiently than teak seedlings. The present series of investigations indicate the scope of CWSI in early detection of crop water stress. As is easy to find out and less time consuming, CWSI has got an immense potential in irrigation scheduling as well as water management.