Ice storage characteristics of fresh and brined shark fillets

Ice storage characteristics of fresh and brined fillets from fresh shark (Carcharias melanopterus) were studied in and out of contact with ice for more than two weeks. Changes occurring in biochemical constituents, physical qualities and bacterial counts of the fillets are reported. Shelf life of brined fillets out of contact with ice was considerably longer than that of control samples tinder similar conditions. Icing of shark fillets is suggested as a method for the removal of urea on a commercial scale.

Input-output relationship and economics of pangas monoculture and carp-pangas polyculture in two districts of Bangladesh

An attempt was made to study the input-output relationships and economics of pangas monoculture and carp-pangas polyculture in Bangladesh. By analyzing the data collected from 50 pangas farms and 55 carp-pangas farms, the study has investigated the production systems of two technologies and the effects of fingerling stocking and applications of feed and fertilizer on fisheries income. The data were collected from the fishermen of Trishal and Bhaluka of Mymensingh district, and Kahaloo and Adamdighee of Bogra district during 2001-02. For pangas monoculture, the stocking density was 31,561 per ha while it was 55,017 per ha in carp-pangas polyculture. Most of the farmers used urea, TSP and lime before stocking. Rice and wheat bran happened to be the most common feed ingredients for both types of culture in general. Other important ingredients used were mustard oil-cakes, rice polish, wheat flour, fish meal, bone meal, soybean meal and poultry litter. In terms of quantities, rice bran and wheat bran dominated the farmers list. Rice and wheat bran together constituted about 60% of all studied feeds. Feed cost constituted 59.13% of total costs for pangas monoculture and 67.44% for carp-pangas polyculture. Per ha productions of pangas and carp-pangas in a single culture cycle were 15,508 kg and 19,745 kg, respectively. Per ha gross profits were estimated to be Tk 310,311 and Tk 464,418 for pangas monoculture and carp-pangas polyculture, respectively. Net profit appeared to be Tk 264,216 per ha for pangas monoculture and Tk 416,509 per ha for carp-pangas polyculture. The BCRs calculated were 1.46 and 1.68 for monoculture and polyculture, respectively. The break-even costs per kg of fish were estimated at Tk 36.93 for pangas and Tk 30.93 for mixed species which was much lower than the prices the producers received. Break-even productions were estimated at 10,702 kg per ha for pangas monoculture and 11,784 kg per ha for carp-pangas polyculture. Fingerling and feed cost, and pond size significantly explained the variation of income from pangas monoculture. These factors have significantly influenced the income from the crop. Functional analysis shows that 1% increase in the feed cost might increase 0.51% of pangas income and 0.41% in carp-pangas income. No other inputs had shown this much of responses to increasing income from a fish.

Protein concentrate from shark

A simple method of leaching the minced muscle with water repeatedly followed by cooking, pressing, drying the cake and powdering has been described for the preparation of fish protein concentrate (FPC) from shark without the use of solvents. The FPC thus prepared had high protein content and was completely free of urea. It contained all the essential amino acids in a balanced proportion with high lysine content and had a storage life up to 12 months. This product can be used for the fortification of bread, biscuits and chappathis respectively at 10, 5 and 2% levels.

Effects of fish and prawn culture on physico-chemical parameters of water and rice yield in rice fields

An experiment was conducted with five treatments i.e. rice combined with fish having regular urea fertilization (T1), rice combined with prawn having regular urea fertilization (T2), rice combined with fish with supplementary feeding (T3), rice combined with prawn with supplementary feeding (T4) and without fish and prawn (T5) was kept as control. The dissolved oxygen values obtained in treatments with fish both in morning and afternoon were lower than the values of prawn containing treatments and control. The values of nitrate-N, ammonia-N, phosphate-P and chlorophyll-a were higher in fish containing treatments than the prawn containing treatments and control. Between the two fish containing treatments the higher gross (539.44 kg/ha) and net (440.14 kg/ha) yield were obtained in T3 with supplementary feeding and the lower gross (424.88 kg/ha) and net (314.32 kg/ha) yield were recorded in T1 without supplementary feeding. Again, between two prawn containing treatments the higher gross (108.69 kg/ha) and net (81.92 kg/ha) yield were obtained in T4 with supplementary feeding and lower gross (64.32 kg/ha) and net (30.98 kg/ha) yield were recorded in T2 without supplementary feeding. The highest yield of rice grain (3.45 mt/ha) and straw (6.37 mt/ha) were obtained in T1 with fish having urea fertilization without feeding.

The survey on determination of malathion biomarker with genotoxicity and ecophysiological reactions in the Caspian roach (Rutilus rutilus caspicus)

In the present study possibility of Malathion biomarker with Genotoxicity and Ecophysiological reactions were determined in Caspian Roach (Rutilus rutilus caspicus). At fist LC50 value of Malathion, an organophosphate insecticide was determined. Then four groups of experimental fish (containing 30 fish in each group) were exposed to different concentrations of Malathion. e. 0, 0.01, 0.05 and 0/1 ppm respectively for 23 days and effects of Malathion on Hematological (RBC, WBC, Hb and Hct) and biochemical parameters (Glucose, triglyceride, urea, total protein and Albumin), some enzymes (SGPT, SGOT and ALP), Cortisol level, plasma cations (Na+ and K+) , histological changes (gill and liver) and finally DNA destruction were examined. Sampling was done in 3rd, 13th, 23rd days during exposure and also 30 days after recovery. Data analysis was done by SPSS (Ver.13) and graphs were drawn by Excel 2007. Results showed that WBC, RBC, Hb, Hct, some biochemical parameters and K+ of Mallation treatments were decreased significantly in compare to control group (P<0.05). Changes in enzyme were many different. No significant changes were observed in Na+ and cortisol levels (except in groups treated with 0.01 Mallation) (P>0.05). LC50 value of Malathion in Caspian Roach was 6.5 ppm. Histological examinations showed that Mallation cause tissue damages and there were more damages in longer times and in higher concentrations. Apoptotic cell and comet were observed as DNA destruction and they were more in treatments with higher Mallation concentrations for longer times.

Effect of organophosphate, diazinon on some immunophysiological, haematological and histological variable of Rutilus frisii kutum (Kamensky,1901)

The acute toxicity and effects of diazinon on some haematological parameters of kutum (Rutilus frisii kutum, Kamensky, 1901) weighing 613.33 g±157.06 g were studied under static water quality conditions at 15°C ± 2ºC in winter and spring 2009. The effective physical and chemical parameters of water were pH= 7-8.2, dh= 300mg/L (caco3), DO= 7 ppm and T= 15°C±2ºC. The first test was primarily to determine the effects of acute toxicity (LC5096 h) of the agricultural toxicant diazinon (emulsion 60%) on kutum male brood stocks. For this purpose, 4 treatments were used to test toxicity; each treatment was repeated in 3 tanks with 9 fish per treatment and with 180 litres water capacity. After obtaining the final results, the information was analysed statistically with Probit version 1.5 (USEPA, 1985), and we determined the LC10, LC50 and LC90 values at 24 hours, 48 hours, 72 hours and 96 hours; the maximum allowable concentration value (LC5096 h divided by 10) (TRC, 1984); and the degree of toxicity. The second stage of testing consists of four treatments: LC0= 0 as experimental treatment, treatment A with a concentration of LC1= 0.107 mg/L, treatment B with concentration of LC5= 0.157 mg/L, treatment C with concentration of MAC value= 0.04 mg/L. Male brood stocks of kutum were treated with these concentrations for 45 days. Experiments were carried out under static conditions based on the standard TRC, 1984 method over 45 days. Our results show that long-term exposure to diazinon causes a decrease in the erythrocyte count (RBC), haemoglobin (Hb), haematocrit (PCV), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), leucocyte count (WBC), lymphocyte, testosterone, iron (Fe), sodium (Na), lactate dehydrogenase (LDH), and cholinesterase (CHeS). In addition, diazinon also causes an increase in prolymphocyte, aspartate aminotransferase (AST), cholesterol, alkaline phosphatase (ALP) and adrenaline (P<0.05). There are no significant effects on monocyte, eosinophil, magnesium (Mg), chloride (Cl), glucose (BS), urea (BUN), uric acid (U.A), triglyceride (TG), calcium (Ca), albumin (Alb), total protein (TP), cortisol, noradrenaline and high density lipoprotein (HDL) levels in kutum male brood stocks (P>0.05). Pathology results showed toxin diazinon no effect on average weight and fish body length, the average weight of heart, brain, spleen, liver, kidney and liver index but caueses decrease of gonad weigth and gonad index and also, cause complications of tissue necrosis, vascular congestion, inflammation in the liver, a sharp reduction in the number of glomeruli, necrosis, vascular congestion and haemorage in the kidney, capsule thickening and fibrosis, atrophy, vascular congestion, macrophages release increased, increasing sediment Hemosiderine and thickening of artery walls in the spleen, atrophy, fibrosis and necrosis in testis , vascular congestion, increased distance between the myocardium and fibrous string in heart and neuronal loss, vascular congestion and edema in the brain of kutum male brood stocks.

Isolating and recognizing crudeoiklegrading [sic] bacteria of Queshm Island shores for biodegradation of crude oil pollutions

This research was carried out for recognizing Natural Flora Bacteria of oil pollution in the coasts of Queshm island. In The First steps, The coasts of this Island were scrutinized as a Field of research and For knowing whether oil stains exist or not. It gets obvious That southern coasts of Queshm have got oil pollution which is created by oil tankers which carry oil of Iran continental shelf. Them oil stains were sampled from to certain stations. In The First step, primary isolation of exisiting bacteria in every oil sample was done and then purification of each bacterium was carried out. Then each purified bacterium that has got strong, recognized, typic growth was enriched oil sample of T5 station. And Bacterium C4 (gram—negative coccobacillus) was chosen as the second priority From oil sample of TA station and Bacterium B1 (gram—positive coccus) was chosen as The third priority From oil sample of TI station. All The above mentioned bacteria were biochemically, physiologically and morphologically experimented For specking The species. According To The tests done and comparing with The tests done and comparing with the reference Berge y' s, bacterium A5 Pelongs to the species pseudomonas sp and becterium C4 belongs to the species Aeromonas sp and bacterium BI belongs to The species micrococcus sp. In The Last stage, bacterium with The First priority (TA5 pseudomonas sp) was used in the planned microcosm. The sake of optimum and adapting to Laboratory conditions Each enriched and purified bacterium was given a code for station and a code For itself . Then This bacterium was studied and it was proved that it has potentiality For using oil as a source of carbon. From oil samples of 10 stations, 30 various Colonies of bacterium were Isolated, of which 20 bacteria had the highest potentiality of growth. And the other bacteria that has no typic growth were omitted From being studied. Since all of These 20 bacterium are able to use oil, a bacterium with maximum rate of growth in the presence of crude oil and Lack of other hydrocarbonic sources and with The code A5 ( gram — negative Bacillus ) was chosen as First priority From The mentioned microcosm contains sea water , suspension oil degrading bacterium , crude oil, azote and various concentrations of carbon and Incubated in 30°` and shook 150 PRA1 According to the results , index oil degrading bacterium (pseudomonas sp) belongs oil sample of T5 stations (east of sheeb draz Gulf) which growth best and have the potentiality of degrading oil in 25 glli malas and 50 glli cheese water and with 5 gill urea .

Shrimp (Penaeus monodon Fabricius) production in brackishwater ponds applied varying fertilizer combinations

Details are given of the production of Penaeus monodon in the Philippines reared in brackishwater earthen ponds applied with different fertilizer combinations, namely diammonium phosphate, urea and chicken manure. Results show that the shrimp showed higher yields in fertilized ponds, but increasing the concentration of fertilizers did not give a marked increase in yield - the excess fertilizer was wasted.

Mouse Toxicity of Anabaena flos-aquae from Lake Dianchi, China

Some species of the genera Anabaena can produce various kinds of cyanotoxins, which may pose risks to environment and human health. Anabaena has frequently been observed in eutrophic freshwater of China in recent years, but its toxicity has been reported only in a few studies. In the present study, the toxicity of an Anabaena flos-aquae strain isolated from Lake Dianchi was investigated. Acute toxicity testing was performed by mouse bioassay using crude extracts from the lyophilized cultures. The mice exposed to crude extracts showed visible symptoms of toxicity and died within 10-24 h of the injection. Serum biochemical parameters were evaluated by the use of commercial diagnostic kits. Significant alterations were found in the serum biochemical parameters: alkaline phosphatase (AKP), gamma-glutamyl transpepticlase (gamma-GT), aspartate amino transferase (AST), alanine amino transferase (ALT), AST/ALT ratio, total protein content, albumin content, albumin/globulin (A/G) ratio, blood urea nitrogen (BUN), serum creatinine (Ssr), and total antioxidative capacity (T-AOC). Histopathological observations were carried out with hematoxylin and eosin (HE) stain under light microscope. Severe lesions were seen in the livers, kidneys, and lungs of the mice injected with crude extracts. The alterations of biochemical parameters were in a dose-dependent manner, and the severities of histological lesions were in the same manner. Based on biochemical and histological studies, this research firstly shows the presence of toxin-producing Anabaena species in Lake Dianchi and the toxic effects of its crude extracts on mammals. (C) 2008 Wiley Periodicals, Inc. Environ Toxicol 24: 10-18, 2009.

Hematological and plasma biochemical responses of crucian carp (Carassius auratus) to intraperitoneal injection of extracted microcystins with the possible mechanisms of anemia

Alterations in hematological indices such as decreases in blood cell counts (RBC), hematocrit (Ht) and hemoglobin (Hb) concentrations are key symptoms of anemia. However, few experiments were conducted to examine changes in hematological indices of fish exposed to microcystins that are believed to be fatal to circulatory systems of vertebrates. An acute toxicological experiment was designed to study hematological changes of crucian carp injected intraperitoneally (i.p.) with extracted microcystins at two doses, 50 and 200 mu g MC-LReqkg(-1) body weight. After being i.p. injected with microcystins, the fish exhibited behavioral abnormity. There were significant decreases in RBC in the high-dose group, and in Ht and Hb concentrations in both dose groups, while erythrocte sedimentation rate (ESR) significantly increased, indicating the appearance of normocytic anemia. There were no prominent changes in the three red cell indices, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH,), and mean corpuscular hemoglobin concentration (MCHC). Increases in blood urea nitrogen (BUN) and creatinine (CR) in both dose groups suggest the occurrence of kidney impairment. Alteration in blood indices was reversible at the low dose group. Conclusively, anemia induced by kidney impairment was a key factor to cause abnormity of swimming behaviors and high mortality of crucian carp. (c) 2007 Elsevier Ltd. All rights reserved.

Effects of nitrogen forms on the production of cyanobacterial toxin microcystin-LR by an isolated Microcystis aeruginosa

A cyanobacterial strain, which produced high content of microcystin-LR (MC-LR) but no rnicrocystin-RR (MC-RR), was isolated from the hypertrophic Dianchi Lake in China and identified as Microcystis aeruginosa DC-1. Effects of nitrogen containing chemicals and trace elements on the growth and the production of MC-LR by this strain were Studied. In the presence of bicine, compared with urea and ammonium, nitrate greatly promoted the growth and the production of MC-LR. However, leucine and arginine, which were the constitutional components in the molecular structure of MC-LR or RR, inhibited the production of MC-LR. Iron and silicon up to 10mg/L had little effects on the growth of M. aeruginosa DC-1, but the production of MC-LR was apparently enhanced. Under all conditions studied here, only MC-LR but no RR was detected within the cells of M. aeruginosa DC-1. Thus, chemical forms of nitrogen, rather than the usually concerned the total nitrogen, Lind trace elements played important roles in the production of MC toxins during cyanobacterial blooms.

FATE OF 2 PHENYLBENZOYLUREA INSECTICIDES IN AN ALGAE CULTURE SYSTEM (SCENEDESMUS-SUBSPICATUS)

The bioaccumulation, elimination and degradation of C-14-labelled diflubenzuron (DFB) and of 1-(2-chlorobenzoyl)-3-(4-chlorophenyl)urea (CCU) was studied in a laboratory algae culture system of scenedesmus subspicatus. Algae were exposed at an initial concentration of 200 mug/l for seven days. Neither substance had an inhibitory effect on the growth of algae. The half life of DFB and CCU was 3 and 1 days, respectively, as measured by HPLC. The distribution of C-14 between medium and algae was measured. In the case of DFB radioactivity in algae increased steadily and levelled off at approximately 60 % after 5 days. Due to algae growth BCF values decreased from 4310 to 889 for DFB and from 6719 to 304 for CCU during the exposure period. The relationship between algae density and bioconcentration could be correlated by an adsorption isotherm. Elimination of both compounds was rapid during the first hours.

不同用量脲酶/硝化抑制剂组合对尿素氮转化的影响

试验采用室内模拟培养的方法，在不同用量脲酶/硝化抑制剂组合条件下，对辽宁省2种主要土壤—棕壤和褐土尿素氮转化的动态变化进行了研究。 结果表明，脲酶抑制剂N-丁基硫代磷酰三胺(NBPT)和苯基磷酰二胺(PPD)在施用量为尿素N量的0.05%时便有很好的脲酶活性抑制效果，且抑制效果随着脲酶抑制剂用量的增加而增强。NBPT和PPD在棕壤中的有效抑制时间为14天，在褐土中有效抑制时间为7天。两供试脲酶抑制剂相比，棕壤中PPD抑制效果好于NBPT，而在褐土中NBPT抑制效果好于PPD。 抑制剂组合各处理延缓了尿素的水解。土壤NH4+-N含量在前期较低，高峰值的出现延迟了2-6天；在培养中后期各抑制剂组合处理土壤NH4+-N含量显著提高。 抑制剂组合各处理土壤NO3--N含量在整个培养期均显著的降低。且在整个培养期间均显著降低了土壤NH4+的表观硝化率。在培养中后期，各处理能够增加棕壤有效氮含量；褐土中在第21天有效氮含量显著降低，而在第35天则有所回升。 试验表明，DMPP和DCD用量分别在施氮量的0.2%和0.25%时便可以达到很好的硝化抑制效果，且在棕壤中DCD的抑制效果好于DMPP，而在褐土中DMPP的抑制效果显著好于DCD。

控释肥料氮素释放动态规律及其肥效

采用室内土壤培养试验、盆栽试验和田间试验相结合的方法,研究了包膜尿素肥料Mister在草甸棕壤和褐土中的全N、NH_4~+-N和NO_3~--N的释放规律,及其对水稻籽粒中氮素含量和玉米生物量的影响。并将土壤培养试验结果与土壤培养尿素中添加硝化抑制剂和脲酶抑制剂的结果相比较,来观察包膜肥料对土壤肥力的贡献及包膜肥料和抑制剂的作用效果评价。结果表明,棕壤和褐土培养下的包膜肥料的释放时期较在纯水中的长,M70、M100和M180的NH_4~+-N、NO_3~--N均随培养时间的延长而增加,Ms100的NH_4~+-N、NO_3~--N在前5周释放量很少,5周后,释放速度明显增加,棕壤培养下四种肥料NH_4~+-N>NO_3~--N。褐土培养下的情况类似,只是四种肥料的NO_3~--N>NH_4~+-N,这可能与棕壤和褐土的土壤性质有关。添加抑制剂培养下的尿素水解在第3d出现高峰,而包膜肥料的氮素释放则没有高峰。这是因为抑制剂阻止酰胺态-N水解过程,而包膜肥料的包膜则阻止酰胺态-N的释放过程。因此,包膜尿素肥料能否满足作物最佳养分临期对养分的需求,是值得探讨的问题。盆栽试验和田间试验结果表明,M70和Urea基施处理对作物生物量的贡献最低，说明包膜肥料释放时期要与作物生育期相吻合才能达到最佳增产效果。

硝化脲酶抑制剂对土壤尿素氮转化和作用产量的影响

采用室内培养和田间小区实验相结合的方法，研究了硫脲（TU，0.1％，0.3％，0.5％，1.0％，5.0％）不同浓度以及TU和硝化抑制剂双氰胺（DCD）、脲酶抑制剂苯基磷酞二胺（PPD）组合对土壤脲酶活性、土壤尿素氮转化和玉米产量的影响。室内培养试验表明，硫脲既是一种弱脲酶抑制剂又是一种硝化抑制剂。硫脉对脲酶活性和尿素水解均有显著的抑制作用，但是作用时间较短；硫脉用量为0.1％时，就起到了抑制作用，用量0.3％-1.0％之间差异不显著，用量1.0％-5.0％之间抑制效果随用量增加而加强。硫脉不同用量对土壤NH_4~+-N释放和向NO_3~--N的进一步转化有明显的抑制作用，作用强度随抑制剂用量增加而增强。硫脲不仅仅延缓了土壤NH_4~+-N的释放高峰期一周，而且降低了土壤中NO_3-N的富集，使NO_3~--N的释放高峰期向后推迟了10天。本试验条件下，土壤中的NH_4~+-N向NO3--N转化的时间大约为7～10天；土壤中有效氮的含量主要取决于土壤NH4+-N的含量，受NO3-N含量的影响次之。田间模拟培养表明，硫脲及其抑制剂组合对土壤脲酶活性有显著的抑制作用，抑制时间为2周，其中抑制剂组合TU_1+PPD对脲酶活性的抑制作用持续了65天。TU、TUI+DCD和TUI+PPD，对土壤NH_4~--N的释放有显著的抑制作用，对NH_4~+-N向NO_3~--N的进一步转化有显著的抑制作用，进而影响土壤有效氮的总量。总的来看，硫脲及抑制剂组合的抑制效果，依次是TU_1＋P PD＞TUI＋DCD＞TU_2＞TU_1。硫服及抑制剂组合对玉米株高、百粒重和产量的影响基本是一致的，TU和抑制剂组合Tul十PPD、TU1＋DCD的作用效果显著优于单施尿素，处理之间差异不显著。施用抑制剂显著增加了玉米产量，增产幅度为9.14％～11.49％。