J. Syama Dayal

Central Institute of Brackishwater Aquaculture, Chennai, Tamil Nādu, India

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Publications (20)6.68 Total impact

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    Full-text · Article · Jan 2015 · Indian Journal of Fisheries
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    ABSTRACT: It has been widely accepted that the growing future demand for aquatic products will have to be met by aquaculture. By year 2020, worldwide aquaculture is projected to supply about 120–130 million tonnes of fish to meet the estimated demands (Rana et al. 2009; FAO 2012). Since feed is the single largest operational expense (between 50 and 60 %) in aquaculture, feed cost determines the profitability and sustainability of this agribusiness activity. Although aquaculture supplied more than 63 million metric tonnes of fish to the world’s human food basket in 2011, only two-thirds of this is produced from artificial feeding, and the rest is contributed by non-fed species. However, the percentage contribution by non-fed species is showing a declining trend from more than 50 % in 1980 to the present level of 33.3 %, indicating the significance of the formulated feed in global aquaculture industry and the further increase in demand for formulated feed and ingredients (FAO 2012).
    No preview · Article · Jan 2015
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    ABSTRACT: To evaluate the effect of periphyton, an on-station grow out trial was conducted for 130 days with tiger shrimp, Penaeus monodon @ 8 nos. m -2 in zero water exchange ponds. Bamboo poles (1.8×0.06 m) were fixed @ 2000 nos. ha in treatment ponds for periphyton development. Total bacterial count (TBC) in water was significantly lower (p<0.05) in periphyton based ponds (83.50±11.86×10 3 CFU ml –1 ) compared with control (288.00±90.15×10 3 CFU ml ). The total Vibrio count (TVC) in water had similar pattern which was 35.3% lower in treatment group compared to control. The TBC and TVC in periphyton biomass over the submerged substrate were 333.13±114.14×10 6 CFU g -1 –1 and 151.88±26.37×10 respectively. At the end of the culture period, higher haemocyte count (p>0.05) (10.83±0.71×10 7 cells ml ) and prophenol oxidase activity (p<0.05) (8.65±0.47 U) was recorded in treatment ponds compared to control (9.38±0.47×10 and 5.18±0.51 U). In pathogen clearance test, treatment group recorded significant reduction (p<0.05) of Vibrio harveyi, 3 h post-inoculation. At the end of the trial, 17.90% gain in production and 22.29% reduction in FCR was observed in periphyton group compared to control.
    Full-text · Article · Jan 2015 · Indian Journal of Fisheries
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    ABSTRACT: The predictions of climate change during the recent decades viz., consistent warming trends (increase in frequency of hot days and multiple-day heat wave), increase in extreme rains, and more frequent and intense extreme weather events (flood, cyclone and drought) has greater impact on aquaculture. This impact has been disproportionately felt by small-scale farmers who are already amongst the poor and vulnerable members of the society. The present study in West Godavari District of Andhra Pradesh documented the climate change events experienced by aqua farmers in brackishwater and freshwater areas and their perceptions, attitudes, risk management behaviour, adaptive capacities and impacts on aquatic farming systems through focus group discussion (FGD), extensive survey of 120 farmers through standard questionnaires, and stakeholder workshop (SW). Assessment based on consequence and livelihood scores revealed that seasonal variations with 20- 40% loss in production was the highest risk in both the areas followed by cyclone in brackishwater and high temperature in freshwater areas. Though not very common in every year, cyclones, the major extreme climatic event results in 50 to 100% loss in production. Among the studied aqua farmers, 14% were highly vulnerable to climate change, whereas 55% were moderately vulnerable. Farmer’s adaptation measures, science and technology solutions and policy adaptation measures are discussed to make aquaculture as climate resilient.
    Full-text · Article · Dec 2013 · Journal of agrometeorology
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    ABSTRACT: This article presents the nutritional value of shrimp on the strength of its nutrient composition and daily value (DV%). With its relatively lower lipid content (~ 1%), the DV (%) of 100 g shrimp for an adult human is 75%, 70% and 35% for eicosapentanoic acid + docosahexanoic acid, essential amino acids (methionine, tryptophan and lysine) and protein respectively. The lower atherogenic (0.36) and thrombogenic (0.29) indices of shrimp show its cardio-protective nature. The controversy relating to shrimp cholesterol and the overall health benefits of eating shrimp are discussed to indicate that shrimp should be a regular item in the diet of normolipidemic peoples.
    No preview · Article · Jun 2013
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    ABSTRACT: Changes in the free and total amino acids in embryonic stages of eggs from captive bred greasy grouper, Epinephelus tauvina (Forskal), were analyzed. The fertilized grouper eggs contained 4.08±0.06 μg/egg free amino acids and 23.22±0.31 μg/egg total amino acids. Indispensable leucine, lysine, valine, and dispensable alanine, glutamic acid, and proline were the most prevalent total amino acids while indispensable isoleucine, leucine, lysine, and dispensable alanine, glutamic acid, and serine dominated the free pool. Free amino acids constituted 17.56±0.32% of the total amino acids in the fertilized eggs, decreasing to 14.75±0.25% and 7.48±0.24% in the gastrula and pre-hatch stages, respectively, due to catabolic and anabolic utilization of the free amino acids in embryonic development. There were wide variations in the loss of individual free amino acids during embryonic development: losses of arginine, lysine, threonine, alanine, aspartic acid, glutamic acid, and glycine were very high (>70%) compared to losses of methionine, phenylalanine, valine, cystine, and proline (<40%). Approximately 50% of the disappeared free amino acids was used for anabolic purposes, i.e., protein synthesis, and the remaining 50% was used for catabolic energy. Retention of indispensable amino acids for protein synthesis was higher than retention of dispensable amino acids.
    No preview · Article · Jan 2013 · The Israeli journal of aquaculture = Bamidgeh
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    Full-text · Book · Jan 2013
  • M Poornima · Y Seetang-Nun · S V Alavandi · J Syama Dayal
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    ABSTRACT: Among the emerging diseases in shrimp aquaculture, monodon slow growth syndrome (MSGS) is a major concern in South and Southeast Asia. Shrimp farming in Thailand was severely affected during 2000-2002 due to MSGS, which caused an economic loss, of about US$ 300 million. MSGS is characterized by abnormally slow growth with coefficients of size variation of >35 %, that has impacted P. monodon production in Thailand. A new shrimp virus, Laem-Singh virus (LSNV) was identified to be associated in MSGS affected shrimp. LSNV a RNA virus of about 25 nm diameter is phylogenetically related to the insect-borne viruses in the families Barnaviridae, Tymoviridae and Sobemoviridae an important histopathological observation is exclusively noticed in growth-retarded shrimp. The LSNV infections have been confirmed in various organs of infected shrimp such as lymphoid organ, gills and nervous tissues by various diagnostic techniques such as reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization, quantitative real-time RT-PCR and reverse transcription loop-mediated isothermal amplification combined with a lateral flow dipstick (RT-LAMP-LFD) and these tools are available for the diagnosis of LSNV. Recently, an integrase containing element has been identified in absolute association with LSNV in stunted growth shrimp. The transmission of LSNV through horizontal and vertical routes has been experimentally demonstrated. The known natural host-range of LSNV includes P. monodon and other penaeid shrimp. The putative RdRp gene involved in replication of LSNV was targeted for dsRNA-mediated gene silencing and appeared to be effective in a dose-dependent manner. Since the discovery of LSNV in 2006 in Thailand, it has been added to the list of viruses to be excluded from domesticated specific pathogen-free stocks of P. monodon and it has been recommended that shrimp farmers avoid stocking post larvae positive for LSNV to prevent MSGS in their farms.
    No preview · Article · Sep 2012 · Indian Journal of Virology

  • No preview · Conference Paper · Feb 2012

  • No preview · Conference Paper · Feb 2012
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    V. Rajaram · J. Syama Dayal · K. Ambasankar · S. Ahamad Ali
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    ABSTRACT: Silk cotton cake (SCC) was incorporated in the practical diets of tiger shrimp, Penaeus monodon at 5 different levels (0,2.5, 5.0, 7.5 and 10.0%) by replacing fish meal. Growth cum digestibility study was conducted for 45 d in 5001 experimental tanks using shrimps weighing 2.09 ± 0.06 g with three replications for each treatment. There was significant (p<0.05) reduction in specific growth rate (SGR) and daily growth coefficient (DGC) in shrimps fed diets having more than 2.5% SCC compared to other treatments. Apparent crude protein, lysine and methionine digestibilities decreased (p<0.05) in shrimp fed with more than 2.5% SCC incorporation. The free amino acid profiles of shrimp muscle at 4 h post-feeding indicated significantly (p<0.05) lower levels for lysine and methionine in shrimp fed with higher levels of SCC. Post-prandial ammonia nitrogen excretion (PPANE) on hourly basis revealed that incorporation of SCC has greatly influenced the N excretion. SCC incorporation has not affected the haemolymph protein concentration up to 7.5% and the haemocyanin content up to 5% inclusion. The experimental results indicate that SCC can be incorporated up to 2.5% in the diet of black tiger shrimp P. monodon.
    Full-text · Article · Jan 2012 · Indian Journal of Fisheries

  • No preview · Conference Paper · Dec 2011

  • No preview · Chapter · Nov 2011
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    J Syama Dayal · V Rajaram · K Ambasankar · S Ahamad Ali
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    ABSTRACT: Replacement of fish meal in marine shrimp feeds is assuming greater importance due to increasing economic and ecological considerations. This study evaluated sunflower cake as a replacement for fish meal in tiger shrimp Penaeus monodon juveniles reared both in tanks and in net cages at 26-33 ppt salinity. Five practical diets were prepared by incorporating sunflower cake at 0, 2.5, 5, 7.5 and 10% level by replacing fish meal. The essential amino acid index (EAAI) of test diets ranged from 0.91 to 0.88. Growth and digestibility study was conducted for 45 d in 500 L experimental tanks shrimp weighing 0.51±0.02 g with three replications for each treatment. There were significant (P<0.05) reductions in daily growth coefficients and protein utilization efficiency in shrimp fed with diets having above 2.5% sunflower cake in experimental tanks. The lysine and methionine digestibility (92.4±0.11 and 93.4±0.01%, respectively) was significantly (P<0.05) higher at 2.5% level inclusion than at 10% level (81.67±0.12 and 83.36±0.17%, respectively). The free amino acid profiles of shrimp muscle at 4 h post feeding indicated significantly (P<0.05) lower levels for isoleucine, leucine, lysine and valine in shrimp fed with higher level of sunflower cake. The decreased levels of these essential amino acids could have hampered protein synthesis and in turn growth. With three dietary treatments (0, 5 and 10% sunflower cake diets) a 10-week growth trial was also conducted in net cages with tiger shrimp juveniles weighing 0.2 g. Significantly (P<0.05) lower daily growth coefficients (%/d) were observed in shrimp fed with 10% sunflower cake diet (1.642±0.017) compared to control (1.774±0.024). The results indicate that sunflower cake can be incorporated up to 5% by replacing 20% of fish meal in marine shrimp P. monodon practical feeds without compromising growth.
    Full-text · Article · Jun 2011 · Indian Journal of Geo-Marine Sciences
  • S. Ahamad Ali · J. Syama Dayal · K Ambasankar
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    ABSTRACT: A formulated pellet and ball form feed with 41.6% crude protein, consisting of fish meal, squid meal, shrimp meal, mantis shrimp meal, soyabean meal, bread flour and other additives was evaluated for mud crab, Scylla serrata. Fish meat (tilapia), which is conventionally used for feeding mud crab by farmers was used as control. Crabs with average weight of 151.7 g were stocked in 500 1 oval shaped FRP tanks containing seawater @ 2 crabs per tank with six replicates per treatment. The crabs were fed daily with dry pellets @ 10% of their body weight in a 30-day feeding trial. The crabs showed excellent acceptability of the compounded feed from the start and had shown a weight gain of 36.7% and a feed gain ratio (FGR) of 2.94, compared to 33.5% weight gain and 5.56 FGR shown by the crabs fed with fish meat. The amino acid profiles of the feed, fish meat and the crabs before and after the feeding trial showed that the ratio of indispensable amino acids (IAA) and the dispensable amino acids (DAA) is same (0.8) for both feeds. Performance of dry as well as semimoist form of pelleted feeds also studied. In a 30-day feeding trial, the weight gain of crabs fed dry feeds was significantly higher (p<0.05) compared to moist feeds. It was due to the higher wastage of feed (30.4%) in semi-moist feeds compared to the dry feeds (17.2%). There was no difference in the FGR shown by different feeds. The proximate composition of crabs fed with the different forms of feed also did not show any variation. Dry pellet feed is preferred over the semi-moist form of feed for feeding mud crab.
    No preview · Article · Apr 2011 · Indian Journal of Fisheries

  • No preview · Conference Paper · Dec 2009

  • No preview · Conference Paper · Dec 2009
  • I.S. Azad · J Syama Dayal · M Poornima · S.A. Ali
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    ABSTRACT: Juveniles of milkfish, Chanos chanos (Forsskal), were fed two independent supra dietary levels of vitamins C (500 and 1500 mg kg(-1) feed, T1 and T2) and E (50 and 150 mg kg(-1), T3 and T4). Milkfish fed diets with supra (in addition to the vitamins present in the control diet) and normal levels (T5 containing 90 and 1.2mg of vitamins C and E, respectively, kg(-1) of feed) of vitamins were immunized (ip) with formalin-killed Vibrio vulnificus (FKVV). Priming and booster antibody responses to the injected bacterin were significantly (P<0.05) better in the milkfish juveniles fed supra dietary levels. Survival response of the experimental fish fed supra dietary levels of vitamins (T1, T2 and T3) was significantly (P<0.01) better than that of the control set. Protective response against virulent bacterial challenge of the vaccinated fish fed vitamin-supplemented diets (T2 and T3) was better than the control (T5) and T1 and T4. Memory factor reflecting immunological memory was superior in the fish fed vitamin-supplemented diets. Diets supplemented with either 1500 mg of Vitamin C or 50mg of Vitamin E kg(-1) produced the best antibody responses, final survival and protective response upon challenge. No conclusive inferences could be drawn on the growth responses from the experiment.
    No preview · Article · Aug 2007 · Fish & Shellfish Immunology
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    J Syama Dayal · S Ahamad Ali · K Ambasankar · Pramod Singh
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    ABSTRACT: Protein being the most important and expensive nutrient in shrimp feed, determination of its appropriate level in relation to the digestive capacity of shrimp is essential in order to make the feed cost effective as well as to minimize the nitrogenous waste excretions. Six diets having different levels of crude protein (30-41 %) were investigated by in vitro digestibility method using the homogenate of hepatopancrcas (digestive proteases) of tiger shrimp Penaeus monodon. Peak digestibility of dietary protein was observed at 3 hours incubation. Maximum digestibility of protein (69.19%) was recorded with diet having 35.28% protein. The in vivo results in tiger shrimp (2.0 g) also showed that the weight gain in the shrimp was also highest at this dietary protein level. The average apparent protein digestibility was highest (76.02 %) in animals fed with diet having 35 % crude protein. The results of the study suggested that dietary protein for P.monodon can be lowered to 35 %, considerably reducing the cost of the feed and making it more environmental friendly.
    Full-text · Article · Jun 2003 · Indian Journal of Geo-Marine Sciences
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    ABSTRACT: Fertilized eggs and developing larvae of hatchery reared Asian seabass, Lates calcarifer (Bloch), were analyzed to determine the changes occurring in their proximate and amino acid (AA) composition. The fertilized dry egg weighed 31 μg and contained 13.71 μg (44%) protein, 8.48 μg (27%) lipid and 0.657 J of gross energy. Dry weight decreased by 39% during hatching. The protein, lipid and carbohydrate nutrients decreased by 4.86, 4.15 and 0.09 μg, respectively from egg to 2-days post hatching (dph) larvae (pre-feeding). The protein content of the spawned eggs and larvae were hydrolysed to AA in the laboratory. The fertilized eggs had a total AA content of 42% of their dry weight. The egg contained 1.287 μg, 1.132 μg, 0.964 μg, 0.942 μg, 0.787 μg and 0.713 μg of leucine, lysine, arginine, valine, threonine and phenylalanine, respectively and these six indispensable amino acids (IAA) constituted approximately 78% of the total IAA. In the early feeding stages of L. calcarifer larvae, the ratio of IAA/DAA increased from 0.797 in the pre-feeding stage to 1.632 after 2 days of feeding. During larval growth of L. calcarifer, the percentage contribution of isoleucine and leucine to total IAA contents increased, while it decreased for lysine, phenyl alanine and arginine. L. calcarifer larvae were found to have proteins, which are rich in glutamic acid, leucine and lysine, and poor in threonine and histidine, suggesting high dietary leucine and lysine IAA requirement.
    Full-text · Article · May 2003 · Fish Physiology and Biochemistry