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Zinc (Zn) and vitamin E (VE) are essential micro-nutrients that contribute a pivotal role in the physiology and nutrition of fish. An experiment was designed to know the effects of Zn and VE addition in the diet on growth and feed utilization in Nile tilapia (Oreochromis niloticus). Four diets containing Zn (80 mg/kg), VE (50 mg/kg), Zn (80 mg/kg) + VE (50 mg/kg), and without Zn and VE (control) were fed to Nile tilapia in aquaria with triplicate groups for 6 weeks. Survival, growth parameters (weight gain, WG; %WG; specific growth rate, SGR), and feed utilization (protein efficiency ratio, PER; feed conversion ratio, FCR) were calculated at the end of the feeding trial. Several hemato-biochemical parameters (hemoglobin, Hb; red blood cell, RBC; white blood cell, WBC, and glucose) and morphology of muscle were analyzed. The growth parameters (WG, %WG, and SGR) and feed utilization (FCR and PER) improved significantly in the fish fed with Zn, VE, and Zn + VE supplemented diets. There was no significant change in the values of Hb, RBC, WBC, and glucose level among different groups. Significantly improved diameter of muscle fiber, reduced distance between muscle fiber, and increased number of the nucleus and hyperplastic muscle fiber were observed in the fish fed with Zn, VE, and Zn + VE supplemented diets. These results suggested that Zn and VE can be effectively incorporated into the diets of Nile tilapia for better growth with maximum feed utilization.

Zebrafish, Danio rerio belonging to the family Cyprinidae is one of the most important native ornamental model species used in fisheries research globally. The present study was conducted to evaluate the effects of sex ratio on the spawning of zebrafish and to observe the ovarian maturity in the laboratory condition. This experiment was conducted for 12 weeks in the glass aquaria (25×16×26 cm3 in size) and the zebrafish were reared in five different sex ratio treatments like -T1 (1m:1f), T2 (1m:2f), T3 (1m:3f), T4 (2m:1f) and T5 (3m:1f) and the fertilized eggs were collected daily from the aquaria. The results showed that mean number of eggs was found to be highest at T3 (821±67.11) and the average egg lay day interval was 1.9 days which significantly (p

The flagship animal species of Sundarbans, the Royal Bengal tiger (Panthera tigris tigris) is under threat of extinction. Its natural population is declining day by day. So, to avoid killing and harming the animal, the use of non-invasive samples such as scat, hair, or scent is preferred for DNA extraction and subsequent genotyping of tiger species. DNA has been extracted from scat samples of the Bengal tiger in the present study, and a fragment of the cytochrome b gene has been sequenced after PCR with species-specific primers. DNA has been extracted manually using a previously described methodology with slight modifications. The size of the PCR product and sequence of cytochrome b gene indicates that tiger DNA is successfully extracted from scat samples using tigerspecific primers. Thus, presence of tiger DNA can be detected by using this method just by the PCR product size in the gel. This is the first report of a partial sequence of mitochondrial cytochrome b gene of P. t. tigris from Bangladesh. Dhaka Univ. J. Biol. Sci. 30(2): 325-330, 2021 (July)

Climate change is responsible to a certain extent for the occurrence and spread of arboviral pathogens worldwide. Temperature is one of the crucial abiotic factors influencing the physiological processes of mosquitoes. Several genes of heat shock protein (AaeHsp26, AaeHsp83, and AaeHsc70) families are known to be expressed in mosquitoes, which aid in overcoming stress induced by elevated temperature. In this study, the relative expression of heat shock protein genes has been examined using Quantitative Real-time PCR (qPCR). The temperatures used for heat shock treatment were 27(control), 37, and 42°C for 1 hour heat shock period and applied to 3rd instar larvae. Significant up-regulation has been seen at 37, and 42°C. The highest expression level, about 82.43 fold, was reported for the AaeHsc70 gene at 42°C followed by 78.36 fold for AaeHsp26 at 37°C and 4.79 fold for AaeHsp83 at 42°C. The current study has shown that HSPs are important markers of stress and may function as critical proteins to protect and enhance the survival of Ae. aegypti larvae and pupae. Biological implications of these findings could impact the vector competencies Dhaka Univ. J. Biol. Sci. 30(2): 233-241, 2021 (July)

Evaluation of Trichoderma harzianum in reducing mycelial growth of Phytophthora infestans as well as in controlling late blight of potato was done in Microbiology and Biocontrol laboratory and Net-house, Department of Plant Pathology, Bangladesh Agricultural University, Mymensingh during 2019-2020, Bangladesh. The experiment was conducted using popular potato variety Diamant and native variety Challisha. T. harzianum was evaluated in net-house and in-vitro condition. Fungicide Indofil M-45 (Mancozeb) was used as positive check for comparison. In Net-house experiment, T. harzianum increased plant height, number of tubers and fresh weight of tubers over control treatment for the both of the varieties of potato. T. harzianum on late blight of potato (var. Diamant) showed a significantly better management over control treatment. In comparison to non-treated control treatment, reduced infection of late blight was found in the T.harzianum treated plants, whereas increase disease severity was calculated in control treatment. After harvesting, tuber infection in T. harzianum treated plants was not observed. Percent inhibition of tuber infection over control was 100%. Indofil M-45 suppressed Disease severity but comparatively less effective than T. harzianum in the long run. In case of variety Challisha similar trend of results were observed. In dual culture assay, T. harzianum showed highest inhibitory effect in suppressing mycelial growth of P. infestans. T. harzianum showed 86.67% inhibition of mycelial growth of P. infestans over control. Thus, it can be concluded that T. harzianum is effective to control late blight of potato and sometimes comparable to chemical fungicide in net-house condition.

Live spore Sterne 34F-2 strain of Bacillus anthracis vaccine is being used to control anthrax disease in Bangladesh. After produced this vaccine in Livestock Research Institute (LRI) under the Department of Livestock Services (DLS), it is distributed at the farmers level through district and Upazila Livestock Offices. In these distribution pathways, the vaccine has been transported and stored for a few days in each station. The present study was carried out to evaluate the humoral immune response of the anthrax vaccine and to measure the impact of existing transportation and storage systems on immunity status. For that a total of 60 cattle were randomly selected , divided into three groups and used the vaccines collected from three distribution points. Serum samples were collected before and after the 1st month, 4th month, 7th 10th, and 13th month of vaccination respectively the anthrax antibody level in blood were monitored. The optical density was converted to ELISA units (EU) and used to express the antibody level in the vaccinated animals. It was significantly increased above the protection level (1.00) for a year. Before vaccination, the average ELISA unit of serum sample was 0.18± 0.01, after vaccination it was raised above the protective level (1.00) within one month and continued up to a year. In the chi-square test (95% confidence level), there was no significant difference (p

Indiscriminate use of pesticides in agricultural land poses a potential threat to many non-target organisms, including fish. In the present study, we explored the toxicological effects of sumithion on Nile tilapia (Oreochromis niloticus) after exposure at different concentrations (0.0, 1.5, 2.0, 2.5, 3.0, 3.5 and 4.0 mg/L) in triplicate for 96 h. The 96-h LC50 value of the pesticide for the test fish was calculated by probit analysis, which was 2.579 mg/L. We also investigated the haematological parameters, erythrocytic alteration and histopathological responses of Nile tilapia. Red blood cell (RBC) and haemoglobin (Hb) level were significantly declined, whereas white blood cell (WBC) and blood glucose level were increased dramatically in the sumithion treated fish. The frequencies of erythrocytic cellular and nuclear alterations were significantly elevated in the fish after exposure to sumithion compared with the control group. The substantial histopathological alterations were observed in sumithion-exposed fish, including pyknotic nucleus, melano-macrophage centers and severe congestion of blood vessels in the liver and patch degeneration, vacuolation and intense form of pyknotic nuclei in the kidney. Observed alterations in this study exhibit that sumithion negatively impacts on Nile tilapia. It is recommended that the use of this pesticide in the agriculture field be monitored and controlled.

Temperature is among the critical determinants of the physiology of fishes and other heterotherms throughout the life history. Temperatures outside of the optimal range distress embryonic and larval development with untoward consequences later in life. To understand the effect of high temperature on embryogenesis and organogenesis, the commercially important rohu carp (Labeo rohita) was chosen. Rohu embryos and larvae were reared at four different temperatures (30, 32, 34, and 36 °C), and indices of their hatching, development, and mortality were observed throughout early development. Embryos exposed to 30 and 32 °C showed normal development with highest rates of hatching success. Embryos at 34 °C displayed evidence of damaged zygotes, cellular deformities, damaged yolk sac coupled with shortest incubation time, and the lowest rates of hatching success. No hatching was observed at 36 °C, and these embryos displayed coagulated organs, dark yolk sac, irregular segmentation, and pustules. Larvae of rohu exposed to 34 and 36 °C showed developmental deformities (fusion in the eye, axial curvature, yolk sac ulceration, blood coagulation, tail shortening, and ulceration) and minimal survival. Our results suggest that optimal temperature of rohu embryo and larvae is 30–32 °C or lower; higher temperatures disrupt embryonic metabolism and physiology, resulting in aberrant and unsuccessful early development.

Profenofos is an endocrine-disrupting chemical that can enter into the aquatic ecosystem either through surface runoff or through percolation of a toxicant from the soil. In order to clarify the effect of profenofos on the developmental stages of zebrafish, the embryos were treated with serial dilutions of profenofos (0%, 10%, 25%, and 50% of LC50). Embryos were treated with profenofos for 7 days or until hatching. The toxic endpoints assessed include hatching time, survival, malformation, and heartbeats of the embryos. In a 96-h test on zebrafish embryos, the LC50 of profenofos was 0.057 mg/L. Profenofos considerably lowered survival, increased abnormalities at different ontogenetic stages, and developed malformations of different organs in a concentration-dependent fashion. The identified developmental malformations were fluid accumulation, impaired jaw, short tail, ruptured pectoral and caudal fin, curved body, thin yolk sac tube, and deformed heart. The way of looping arrangement of the heart at the early stage of embryos was significantly influenced by the higher concentration of profenofos. Heartbeat is also reduced significantly in a concentration-dependent fashion. The results show that the zebrafish are susceptible to profenofos even at lower concentrations in the initial stage. Therefore, when used in agricultural areas adjacent to the aquatic environment, endocrine-disrupting chemicals should be used in an appropriate manner.

Sumithion is an organophosphorus insecticide, which is widely used in aquaculture ponds for eradication of aquatic insect (mainly tiger bug) prior to release of larvae. This study was conducted to evaluate the effects of an organophosphorus pesticide, sumithion on histoarchitecture of liver and kidney in common carp (Cyprinus carpio) during the period from July to December 2016. It was carried out with four treatments, each with two replications. i.e., ponds with no sumithion (T0), with 0.025ppm sumithion (T1), 0.050 ppm sumithion (T2) and 0.100 ppm sumithion (T3). The water quality parameters, such as pH, dissolved oxygen, total alkalinity, free CO2, nitrate-nitrogen (NO3-N), phosphate-phosphorus (PO4-P) were not affected by sub lethal doses of sumithion but the values were fluctuated significantly in most of the cases between the ponds throughout the study period. In case of histoarchitecture of liver and kidney, normal structure of liver and kidney cells were observed in the controlled and treated fish. Through the histological analysis of liver, small vacuole, enlarge lumen space of hepatopancreas and disrupted hepatopancreas were found in T1. Disrupted hepatopancreas, increasement intracellular space, regeneration of hepatic cell and hemorrhage were observed in T2. Moreover, enlarge lumen space of hepatopancreas, degenerated hepatic cell, disrupted hepatopancreas were observed in T3. After the histological analysis of kidney, degenerated renal corpuscle, enlargement of blood vessel, disrupted hematopoetic cell were observed in T1. Ruptured collecting duct, large vacuole, enlarge intracellular space were observed in T2. Furthermore, enlarge bowman’s space, degenerated hematopoetic cell hemorrhage and ruptured distal tubule disrupted, enlarge intracellular space and necrosis were observed in T3. The present investigation sufficiently emphasizes that sumithion has adverse effects on the major organs like liver and kidney. Int. J. Agril. Res. Innov. Tech. 10(2): 66-75, December 2020

Field evaluation of BAU-Biofungicide and plant extracts was performed to manage leaf blight of wheat caused by Biopolaris sorokiniana from November, 2015 to April, 2018. Two susceptible varieties of wheat viz., Kanchan and Prodip were used in the experiment. Aqueous extracts of neem leaf and garlic clove, Trichoderma based preparation BAU-Biofungicide and an inducer Bion were evaluated in the field as seed-treatment or seed-treatment along with foliar application. In addition, a chemical fungicide (Tilt) was used as positive control and an untreated negative control were included in the experiment. Based on the three years of experiment in three cropping seasons during 2015-16, 2016-17 and 2017-18; seed treatment with BAU-Biofungicide was found highly effective to reduced leaf blight severity in both cultivars. The lowest disease severity was observed in plots where Tilt was used as spray followed by seed treatment with BAU-Biofungicide plus BAU-Biofungicide spray. BAU-Biofungicide showed better performance in controlling leaf blight of wheat. Based on the findings of the present study, BAU-Biofungicide potentially reduce the severity of Bipolaris leaf blight of wheat therefore, it could be an effective option for the growers for eco-friendly management of leaf blight disease of wheat and obtaining higher yield. [J Bangladesh Agril Univ 2020; 18(4.000): 916-922]

Heavy metal pollution due to anthropogenic activities poses a great threat to aquatic organisms. The present study was conducted to evaluate the cytotoxic and genotoxic effects of hexavalent chromium (potassium dichromate) on hemato-biochemical, histo-pathological, and genetical changes in striped catfish Pangasianodon hypophthalmus. Three sub-lethal doses (0.8, 1.6, and 3.2 mg/L) of chromium (Cr) were selected and fish were exposed in vivo contrasting with a control (0 mg/L) for 30 days. The study revealed that various hemato-biochemical parameters showed a significant decrease in hemoglobin (Hb), red blood cells (RBCs), and blood glucose content, whereas white blood cells (WBCs) significantly increased in Cr exposed fish. Frequencies of all forms of structural abnormalities of erythrocytes (erythrocytic cellular abnormalities; ECA, erythrocytic nuclear abnormalities; ENA and erythroblasts; Ebs) were significantly increased in higher two test concentrations (1.6 and 3.2 mg/L) when compared to control. Differential leucocyte count exhibited significant increase in neutrophil and decrease in lymphocytes in the highest Cr treated group. The severity of various histo-pathological changes in the gills, liver, and kidney were increased considerably with the increase of Cr concentrations. Similarly, the amount of DNA (ng/μl) decreased significantly in blood and tissues of different vital organs where the liver showed the highest decline compared to control in a concentration-dependent manner. Taken altogether, P. hypophthalmus is susceptible to Cr and can be used as a bio-indicator to assess aquatic metal pollution.

Experiencing the seasonal variation and rapid global warming in the tropical climate is a common phenomenon which challenged the aquatic organisms to adapt the physiology and behavior. To investigate the effect of high-temperature acclimation, we selected Indian major carp, rohu (Labeo rohita), a commercially important freshwater aquaculture species. Oxygen consumptions, micronucleus formation in erythrocytes, and gill histopathology were observed in L. rohita fingerlings acclimated at three temperatures (30, 33, and 36 °C) for 30 days. Results showed that the highest acclimated temperature (36 °C) induced higher oxygen consumption and increased frequency of micronucleus formation in erythrocytes. Severity of different histological alterations (hyperplasia, epithelial necrosis, telangiectasis, epithelial lifting, and hypertrophy of chloride cells) in the gills was found to be increased in the highest acclimated temperature (36 °C). These findings indicate the temperature induced adaptive responses and climate vulnerability in a changing environment.

Background We evaluated the impact of low-cost water, sanitation, and handwashing (WSH) and child nutrition interventions on enteropathogen carriage in the WASH Benefits cluster-randomized controlled trial in rural Bangladesh. Methods We analyzed 1411 routine fecal samples from children 14 ± 2 months old in the WSH (n = 369), nutrition counseling plus lipid-based nutrient supplement (n = 353), nutrition plus WSH (n = 360), and control (n = 329) arms for 34 enteropathogens using quantitative polymerase chain reaction. Outcomes included the number of co-occurring pathogens; cumulative quantity of 4 stunting-associated pathogens; and prevalence and quantity of individual pathogens. Masked analysis was by intention-to-treat. Results Three hundred twenty-six (99.1%) control children had 1 or more enteropathogens detected (mean, 3.8 ± 1.8). Children receiving WSH interventions had lower prevalence and quantity of individual viruses than controls (prevalence difference for norovirus: –11% [95% confidence interval {CI}, –5% to –17%]; sapovirus: –9% [95% CI, –3% to –15%]; and adenovirus 40/41: –9% [95% CI, –2% to –15%]). There was no difference in bacteria, parasites, or cumulative quantity of stunting-associated pathogens between controls and any intervention arm. Conclusions WSH interventions were associated with fewer enteric viruses in children aged 14 months. Different strategies are needed to reduce enteric bacteria and parasites at this critical young age.

The study was conducted to reveal various seedling production scenario on floating beds including environmental aspects associating seedling production. Data of various seeding production were collected from total 50 households (HHs) of two villages at Nazirpur Upazila in Pirojpur district of Bangladesh by a pre-tested survey questionnaire. The study showed that 68% farmers did seedling production for business purpose, and 30% as both own and business. During floating cultivation on beds about 50% farmers used their own producing seed and 26% from market. The farmers cultivated 21 different types of vegetables and spices seedlings where highest number of seedling was Bottle gourd (19.11%) followed by Papaya (13.82%) and Chili (12.60%). They used urea as a common fertilizer on floating bed which enriched by TSP (46%) and DAP (40%) during cultivation. It was observed that 32% farmers did seedling cultivation solely as own source of money while 26% got the help from NGOs. After end of the cultivation, 25% beds were sold as compost fertilizer for winter cultivation, 5% were used as own field and 17% farmers utilized the fertilizer as both business and own purpose. The study also revealed that, about 64% of respondent farmers were not suffered by any environmental complications. Adopting modern agrotechnology and minimization of initial cost through subsidy can make this traditional Vasoman Chas has a sustainable agricultural practice. SAARC J. Agri., 18(1): 239-250 (2020)

BACKGROUND: To date, although neonatal infections with severe acute respiratory syndrome coronovirus 2 (SARS-CoV-2) have been described, none of these have been proven to be the result of vertical transmission of SARS-CoV-2. METHODS: We describe the probable vertical transmission of SARS-CoV-2 in a neonate born to a mother with coronavirus disease 2019 (COVID-19). RESULTS: Following cesarean section, the neonate was kept in strict isolation. Molecular tests for SARS-CoV-2 on respiratory samples, blood, and meconium were initially negative, but positive on a nasopharyngeal aspirate on the third day of life. On day 5, the neonate developed fever and coryza, which spontaneously resolved. Viral genomic analysis from the mother and neonate showed identical sequences except for 1 nucleotide. CONCLUSION: This report has important implications for infection control and clinical management of pregnant women with COVID-19 and their newborns.

In Bangladesh, aquaculture has expanded, diversified, intensified and technologicallyadvanced due to the decline in fish production from the open water natural sources. Quality seedsare prime requirements for aquaculture production. Quality of seeds depends on the quality ofbroods used for spawning. Breeding performance depends on the quality of feeds and feedingmanagement during brood stock rearing. The present study focused on the evaluation of qualityof feed used in the fish farms, the performance of brood stock and fingerlings of selected carp,catfish and perch farmed in Bangladesh through a survey. On the basis of top fish productiondistricts, we divided the whole country into four hubs, such as Mymensingh, Jashore, Cumillaand Rajshahi. Data were collected from 300 individual respondents of commercial fish farms, 75from each hub. It has been found that most of the farm owners (91%) used commercial feedinstead of homemade feed, though a considerable number of respondents replied that quality ofhomemade feed was better than commercial feed. Although most of the farm owners collect fryfrom private/own hatcheries (69%), a considerable number of grow out farms owners replied thatthe fry of government hatcheries/brood bank, river and BFRI were better than private hatcheriesin terms of growth performance, disease resistance and survivability. Therefore, for sustainableaquaculture, farm owners should be careful for the selection of feed, brood and fingerling.

Objective: To highlight the prevalence and epidemiology of New Delhi metallo-ß-lactamase-1.producers in pus samples. Methods: The cross-sectional study was conducted from April to August 2018at the Biotechnology Laboratory, Balochistan University of Information Technology Engineering and Management Sciences, Quetta, Hi-tech Laboratory, Centre for Advance Studies in Vaccinology and Biotechnology, University of Balochistan, Quetta, and Microbiology Laboratory, Bolan Medical Complex Hospital, Quetta, Pakistan. Biochemical and molecular approaches were used for the identification of the isolates and Modified Hodge Test for the phenotypic detection of class-A carbapenemase activity. Minimum Inhibitory Concentration was performed using E-test and broth microdilution method. Molecular basis of carbapenemase activity was ascertained by the recognition of blaNDM-1 gene in the isolates. Results: Of the 300 pus samples taken from surgical/burn units,6(2%) blaNDM-1 harbouring isolates were found; 3(50%) each being Klebsiellapneumoniae andPseudomonas aeruginosa. Klebsiella. pneumoniaeisolates were extensivelydrug-resistant. The Pseudomonas aeruginosaisolates displayed resistance against 21 antibiotics of tetracyclines, quinolones, ?-lactams, aminoglycosides, monobactams, sulphonamides, macrolides, cephalosporins, phosphonic acid and polypeptide groups, suggesting pan-drug resistance. Conclusion: The resistance pattern of the bacterial isolates poses a significant clinical threat in the region. Key Words: blaNDM-1, Carbapenemase, XDR, PDR, Quetta.

Salinity intrusion in coastal areas due to climate change is alarming. In this study, the effects of salinity on embryonic and larval development of striped catfish (Pangasianodon hypophthalmus) were studied experimentally. Embryos and larvae were exposed to seven salinity treatments (0, 2, 4, 6, 8, 10, and 12 ppt), each with three replications. Considerable survivability of embryos was recorded up to 6 ppt salinity. Mortality of embryos significantly increased at 8 and 10 ppt salinity, and 100% mortality was displayed within 12 h of exposure at 12 ppt salinity. The rate of hatching was significantly reduced at 8 and 10 ppt salinity. The 24 h lethal concentration (LC50) value of salinity for embryo was 11.24 ppt. Different types of deformities, such as undeveloped yolk sac, elongated gastrula yolk sac, and yolk sac bud, were highest at 10 ppt salinity. Similar to the embryo, considerable survivability of larvae was recorded up to 6 ppt salinity, and 100% mortalities were found within 24 h of exposure at 12 ppt salinity. The 24 and 48 h LC50 values of salinity for larvae were 10.63 and 8.48 ppt, respectively. Several types of deformities, including yolk sac ulceration, spine scoliosis, tail bent, yolk sac edema, and compromised swim bladder inflation, were highest at 10 ppt salinity after 48 h of exposure. Within 24 h of exposure, about 80% yolk sac of the larvae was absorbed at 8 and 10 ppt salinity, while 30%–50% yolk sac was absorbed at 0–6 ppt salinity. Growth rates in terms of length and weight were higher at 0, 2, and 4 ppt salinity and moderate at 6 and 8 ppt salinity. Overall, the current findings define the limits to optimize hatchery procedures for the culture of this species in low saline brackish water.

Plants recognize a variety of external signals and induce appropriate mechanisms to increase their tolerance to biotic and abiotic stresses. Precise recognition of attacking pathogens and induction of effective resistance mechanisms are critical functions for plant survival. Some molecular patterns unique to a certain group of microbes (MAMPs, microbe-associated molecular patterns) are sensed by plant cells as non-self molecules via pattern recognition receptors. While a variety of MAMPs of bacterial and fungal origin have been identified, reports on MAMPs of oomycete pathogens are relatively limited. This study aimed to identify unique MAMP elicitors from the oomycete pathogen Phytophthora infestans, the causal agent of potato late blight. Using reactive oxygen species (ROS) production and phytoalexin production in potato as markers for the purification of oomycete elicitors, we identified two structurally different groups of elicitors, namely ceramides and diacylglycerols. P. infestans ceramide (Pi-Cer) elicitors induced ROS production, while diacylglycerol (Pi-DAG) elicitors, containing eicosapentaenoic acid (EPA) as a substructure, induced the formation of phytoalexins in potato. Pi-Cer and Pi-DAG are also contained in the mycelia of another oomycete pathogen Pythium aphanidermatum, indicating that they are MAMPs of oomycetes. When Arabidopsis was treated with Pi-Cer and EPA, partially overlapping but different sets of genes were induced. Furthermore, simultaneous treatment with Pi-Cer and EPA did not have a cumulative effect on induced genes, but rather the expression of some genes induced by EPA was attenuated by the co-treatment with Pi-Cer. These results indicate that plants may combine the signals from simultaneously recognized MAMP elicitors to specifically adapt the defense response to a particular pathogen.

The experiment was conducted at four laboratory, Bangladesh Agricultural University, Mymensingh to identify T. asperellum and its characterization was obtained from the rhizosphere of 49 different crops in 109 different locations of 36 districts in Bangladesh. Fifteen isolates of 88 isolates in T. asperellum were characterized on morphological and physiological features. All of the isolates were produced at 35 {degrees}C, but only TR27 and TR45 were grown and sporulate at 40 {degrees}C. Mycelial growth of all the isolates was reduced with the increasing of pH value. Molecular characterization in four isolates of TR27, TR45, TR70 and TR85 were studied at ITS and TEF region nucleotide sequencing among 15 isolates of T. asperellum and the morphological characterization at ITS and tef1 nucleotide sequencing was assimilated with molecular characterization. The isolates of TR45, TR70 and TR85 were found with 98% homology and TR27 exhibited 88% against their respective closest isolate. The isolates of TR27 and TR85 marked their respective nearest homology at 96%, while TR45 showed 99%, and 93% homology was signified with TR70 in TEF sequences. Three isolates (TR45, TR70 and TR85) were identified as T. asperellum of 100% bootstrap value and TR27 isolate was also recognized with 72% bootstrap value in phylogenetic tree. In phylogenetic analysis, tef1 extended better differentiation among the Trichoderma isolates within and among the groups of closely related species than the rDNA of the ITS region in reflecting wider variability in the isolates while a higher transversion ratio and evolutionary divergence were defined. Moreover the exploring of scientific and useful diversification of Trichoderma isolates on physiological and molecular traits has deemed in research fields. IMPORTANCETrichoderma is an important genus in different aspect of uses as biofertilizer and bioremediation in agriculture. Specific identification in physiological and molecular characterization has also foremost attention with genome sequences as stored in databases. The diversity and genetic distances were ascertained among the isolates in phylogenetic analysis with the sequence data of the ITS region and tef1 of known Trichoderma strains was found in GenBank. Consequently, the databases of Trichoderma asperellum in molecular characterization can be frequently studied in the beneficial scope of agriculture. Trichoderma isolates of Rhizosphere soil in 4 locations with crops of (TR27) Sadar, Moulvibazar (Rice), (TR45) Sadar, Mymensingh (Sweet gourd), (TR70) Chapra, Chapai Nawabganj (Sesame) and (TR85) Nayanpur, Lalmonirhat (Maize) were found to be substantiated as Trichoderma asperellum strain in Bangladesh that were confirmed on physiological and molecular characters, and utilization of this strain can run faster in invasive technologies to control crop diseases.

Global warming and indiscriminate usages of pesticides are notable concern to all. The present study has been conducted to evaluate the effects of high temperature on acute toxicity of sumithion in adult zebrafish. A 2-day renewal bioassay system was used to determine the 96 h LC50 value of sumithion at three temperature regimes, such as 25 °C, 30 °C, and 35 °C. Blood glucose (mg/dL) level was measured in control (0.0 mg/L) and low concentration (1.0 mg/L) of sumithion during the determination of LC50 in three temperature conditions. In addition, micronucleus (MN), erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA) tests were performed in the blood erythrocytes. The 96 h LC50 value of sumithion for zebrafish was significantly lower at 35 °C, which indicates that the toxicity of sumithion increases at higher temperature. Blood glucose level was significantly increased by sumithion in all temperature conditions, while it was significantly higher in the highest (35 °C) temperature compared to the lowest (25 °C) temperature in both control and sumithion-treated fish. Similarly, frequencies of MN, ENA, and ECA were elevated by sumithion in all temperature conditions, whereas it was significantly raised in the highest (35 °C) temperature compared to the lowest (25 °C) temperature in both control and sumithion treated fish. With increasing temperature in exposure to sumithion, dissolved oxygen decreased significantly, whereas free CO2 increased significantly. On the other hand, no distinct changes were observed in pH and total alkalinity during the experimental period. Therefore, it can be inferred that increasing temperature enhances the toxicity of sumithion in the zebrafish.

Culex quinquefasciatus Say is an important pest species and a vector of multiple pathogens. Insecticide applications are necessary for the effective control of mosquitoes. In the current study, a laboratory population of Cx. quinquefasciatus was exposed to chlorpyrifos for 15 consecutive generations and then assessed for the changes in detoxification enzyme activities before and after exposure to Metarhizium anisopliae (Metschn.) Sorokin and Beauveria bassiana (Bals.) Vuill. during 14th–15th generations. Activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), esterase (EST), acid phosphatases (ACP), and alkaline phosphatases (ALP) were increased in the chlorpyrifos-selected (Chlor-SEL) population in relation to an unselected (Un-SEL) population. The resistance ratio of Chlor-SEL 15th generation (G15) was increased 3,583-fold against first generation (G1) and 6,026-fold against the Un-SEL population. The results depicted maximum activities of ACP (83.48), ALP (65.54), GST (13.047), EST (10.42), and AChE (4.86) μmol/min of mg/ml protein at G15 after consecutive chlorpyrifos applications. The Chlor-SEL populations at G14–G15 were treated with different concentrations of M. anisopliae and B. bassiana for possible suppression of enzymatic activities. Activities of ACP were suppressed to 24.22 μmol/min of mg/ml protein at G15 when exposed to B. bassiana and 22.40 μmol/min of mg/ml protein at G14 after exposure to M. anisopliae. The suppression of detoxification enzymes by application of fungi in resistant population of Cx. quinquefasciatus will aid in the mosquito’s management programs.

Quantitative and qualitative analyses of important bacterial content for public health concern (total bacterial count, total coliforms, faecal coliforms, Salmonella and Vibrio cholerae) of cultured fresh water prawn and farm water which has significant role in order to manage sustainable aquaculture were carried out. Microbiological parameters of prawn (Macrobrachium rosenbergii) and farm water were determined by following the ISO standard methods. Total bacterial Count (standard plate count) found in prawn samples ranged from 5.55 to 5.71 log CFU/g while 4.13 to 4.18 log CFU/mL in water sample. On the other hand, total coliforms found in prawn sample ranged between 1.96 to 2.46 log CFU/g whereas in water sample 2.07 to 2.46 log CFU/mL total coliforms were detected. In case of faecal coliforms, the number ranged between 0.96 to 1.42 log CFU/g in prawn sample and 1.59 to 1.81 in water sample. While Vibrio cholerae was absent in both prawns and water sample and Salmonella was detected in two tested ponds for both prawn and water sample.

An experiment on the use of duckweed powder as a fish feed on monoculture of silver carp (Hypophthalmichthys molitrix) was conducted in 6 ponds for a period of 75 days. The area of the each pond was one decimal. The experiment was carried out under two treatments, each with 3 replications. A combination of duckweed powder and rice bran at the ratio of 3:1 was supplied at the rate of 4% of total body weight in the ponds under treatment-I. On the other hand, the ponds under treatment-II were without supplying of feed. Each of the ponds under both treatments were stocked with 45 fingerlings of silver carp (H. molitrix). The average initial length and weight of the fingerlings were 14.60 cm and 33.48 g, respectively. The ponds were fertilized fortnightly with poultry droppings at the rate of 2 kg, urea 60 g and TSP 90 g decimal-1. During the experimental period the ranges of physico-chemical parameters viz. water depth (0.82 to 0.90 m), water temperature (17.80 to 26.7 °C), air temperature (19.11 to 28.29 °C), transparency (28.00 to 34.00 cm), dissolved oxygen (6.70 to 8.20 mg L-1), pH (6.70 to 8.00), total alkalinity (170 to 210 mg L-1), free CO2 (0.0 to 3.50 mg L-1), phosphate-phosphorus (1.2 to 2.9 mg L-1), and nitrate-nitrogen (3.1 to 4.5 mg L-1) were within the productive limit and more or less similar in all the ponds under treatments I and II. There were 25 genera of phytoplankton under four major groups and 10 genera of zooplankton under three major groups in the experimental ponds. Mean survival rates under treatment-I and treatment-II were 97.78% and 95.56%, respectively. The specific growth rates (SGR % per day) of the fish found under treatment-I and treatment-II were 0.98% and 0.49%. The calculated net production of the ponds under treatment-I was 1.87 ton ha-1 yr-1 and that of the ponds under treatment-II, was 0.74 ton ha-1 yr-1. By 't' test, it was found that the net fish production of treatment-I was significantly (p

The biology and feeding potential of plain tiger butterfly, Danaus chrysippus L. (Lepidoptera: Danaidae) were examined in both field and laboratory conditions from July 2011 to June 2012. Field collected singly laid eggs on host plant (Asclepias curassavica) were reared in the laboratory at room temperature (25 ± 3 °C) and 70 ± 5% RH. Various life stages of the butterfly, viz. egg, larvae, pre-pupa, pupa and adult have been described. The egg incubation period was 4.6 ± 0.8 days; the duration of larval stages from 1st to 5th instars were 1.7 ± 0.2, 2.2 ± 0.2, 2.5 ± 0.3, 2.7 ± 0.2 and 3.1 ± 0.4 days, respectively; pre-pupal period was 1.4 ± 0.4 days; pupal period was 8.6 ± 1.1 days; the longevity of the adult females was 7.8 ± 0.3 days and of the males was 10.4 ± 0.7 days. The larval lengths of each of the five instars were 3.7 ± 0.84, 8.7 ± 1.09, 14.3 ± 1.20, 23.2 ± 2.36 and 38.5 ± 2.54 mm, respectively. The feeding potential rates of the five instar larvae were 5.5 ± 1.11%, 22.8 ± 2.96%, 67.7 ± 2.99%, 96.8 ± 4.09% and 293.6 ± 15.9%, respectively. The weights (in gram) of the excreta of five larval instars were 0.06 ± 0.02, 0.13 ± 0.03, 0.54 ± 0.06, 0.81 ± 0.06 and 1.96 ± 0.09, respectively. A total of 187 individuals was observed on 16 potential nectar plants in the Butterfly Research Park (BRP), Gazipur. These were Lantana camara, Asclepias curassavica, Duranta plumeri, Hibicus rosa sinensis, Duranta repens, Tagetes patula, Ixora chinensis, Heliotropium indicum, Cosmos bipinnatus, Wedelia calendulaca, Punica hybrida, Spilanthes calva, Leucas linifolia, Helianthus annus, Euphorbia pulcherrima and Gomphera globosa. Among these, L. camara was visited most frequently (16.58%) and L. linifolia was least frequently (1.60%) by this butterfly. No Danaus chrysippus was observed visiting H. annus and E. pulcherrima plants. J. Biodivers. Conserv. Bioresour. Manag. 2019, 5(1): 121-132

Samples of Drosophila species were collected from some selected sites (viz., Dohar Upazila of Dhaka Division, Hironpoint of the Sundarbans, Satchori of Sylhet Division) of Bangladesh and these were cultured in the laboratory to study developmental stages, external morphological traits and sex comb. They were identified as D. melanogaster, D. ananassae and D. bipectinata. The sex comb teeth number and arrangement were distinct for all three species. D. melanogaster had one row of 10 - 11 teeth in the sex comb. D. ananassae had eight rows of teeth in the sex comb possessing 32 - 33 teeth in total. D. bipectinata had 2 - 3 rows of teeth in the sex comb and total teeth number varied from 11 to 15. Among three species, sex comb teeth number of D. bipectinata varied most. Eleven different patterns (n=20) in sex comb were observed in D. bipectinata indicating significant diversity within species. Variation in pupation sites among three species was also observed in the laboratory condition. D. bipectinata pupated on the food medium, whereas other two species pupated on the vial wall. Thus, diversity among these three species of Drosophila was documented which could be utilized as bioindicator in future. Dhaka Univ. J. Biol. Sci. 28(2): 167-176, 2019 (July)

Attempts were made to combine morphological and molecular techniques for identification and analysis of evolutionary relationship of commercially important marine lizardfish (Bombay duck) from the Bay of Bengal. For molecular identification, mitochondrial DNA (mtDNA) was extracted using CTAB extraction protocol and 16S rRNA gene was amplified by PCR method. Morphological identification was supported by molecular data generated by 99% identity of BLAST search result of Harpadon nehereus. The nucleotide sequence of H. nehereus was 586 bp long and the G+C content was 51% and intraspecies polymorphic sites were 0.5%. According to interspecies polymorphic sites analysis, 4.9% polymorphism was observed when H. nehereus and H. microchir were compared. Phylogenetic tree was constructed and both the Harpadon spp. formed a monophyletic clade. This analysis will be used to study molecular diversity as well as conservation of this fish species. Bangladesh J. Zool. 47(1): 49-57, 2019

The present research work was conducted to evaluate the effects of organophosphate insecticide, sumithion on water quality parameters, density of plankton population and histological changes of kidney and liver of the fish, tilapia (Oreochromis niloticus) in aquaculture ponds during July to December 2016. The experiment was conducted with four treatments, each with two replications. Treatment T0 was used as control (no sumithion) and other three treatments with 0.025 ppm (T1), 0.050 ppm (T2) and 0.100 ppm sumithion (T3). The water quality parameters such as dissolved oxygen, free carbon dioxide, pH, total alkalinity, NO3-N and PO4-P fluctuated significantly under four treatments during the experimental period but they were not affected by sumithion application. The phytoplankton densities (×105 cells L-1) was not affected by sumithion. Six genera of phytoplankton populations were found in the experimental ponds. On the other hand, zooplankton population densities (×103 cells L-1) were significantly reduced with increasing doses of sumithion (T2 and T3) in comparison with that of control (T0). Histological changes of kidney were observed after application of sumithion. The renal corpuscle, collecting duct, hematopoietic cells and other cells of the kidney in control (T0) were normal and systematically arranged. Abnormal collecting duct, Intra-cellular space, degenerated renal corpuscle, irregular shaped blood vessel, ruptured membrane large vacuole and necrosis were found in T1, T2 and T3.Normal structure of liver cells such as hepato-pancreas, hepatic cell and blood vessel were observed in T0 (control). Sumithion exposed liver sections showed rupturedhepato-pancreas, necrosis, hemorrhage, intra-cellular space, degenerated hepatopancreas and large vacuole were found in T1, T2 and T3. Therefore, it reveals that sumithion has adverse effects on kidney and liver of the test fish. So, sumithion should not be used indiscriminately in agriculture and aquaculture practices. It may be concluded from the research finding that dissolved oxygen, free carbon dioxide, pH, total alkalinity, PO4-P, NO3-N, phytoplankton and zooplankton values under treatment, T0, are significantly different from treatments T1, T2, and T3 in most cases. Int. J. Agril. Res. Innov. & Tech. 9 (1): 84-95, June, 2019

In Bangladesh, aquaculture is critically important in terms of providing food and nutrition, sustainable livelihoods, income, and export earnings. Nevertheless, aquaculture in Bangladesh has faced recent concerns due to climate change. Aquaculture is vulnerable to a combination of climatic factors, such as global warming, rainfall variation, flood, drought, temperature fluctuation, and salinity change. Considering the vulnerability of fish production to the impacts of climate change, tilapia farming is one of the possible strategies for adaptation to climate change. The positive culture attributes of tilapia are their tolerance to low water levels and poor water quality with rainfall variation, temperature fluctuation, and salinity change. In fact, tilapia farming is possible in a wide range of water environments, including freshwater, brackish water, and saltwater conditions. We suggest that appropriate tilapia culture strategies with institutional support and collaboration with key stakeholders are needed for adaptation to environmental change.

Decomposed organic materials, in combination with plant growth-promoting bacteria (PGPB), are environmentally friendly and reduce synthetic fertilizer use in rice production. A bio-organic fertilizer (BoF) was prepared using kitchen waste (79%), chita-dhan (unfilled rice grain) biochar (15%), rock phosphate (5%), and a consortium of 10 PGPB (1%) to supplement 30% nitrogen and to replace triple superphosphate (TSP) fertilizer in rice production with an improvement of soil health. PGPB were local isolates and identified using 16S ribosomal RNA partial gene sequences as Bacillus mycoides, Proteus sp., Bacillus cereus, Bacillus subtilis, Bacillus pumilus, Paenibacillus polymyxa, and Paenibacillus spp. Isolates could fix N2 by 0.7–1.4 g kg–1, solubilize 0.1–1.2 g kg–1 phosphate, and produce 0.1–40 g kg–1 indoleacetic acid. The performance of BoF was evaluated by 16 field experiments and 18 farmers’ field demonstration trials during the year 2017–2020 in different parts of Bangladesh. Performances of BoF were evaluated based on control (T1), full synthetic fertilizer dose of N, P, and K (T2), BoF (2 t ha–1) + 70% N as urea + 100% K as muriate of potash (T3), 70% N as urea + 100% P as TSP + 100% K as muriate of potash (T4), and 2 t ha–1 BoF (T5) treatments. At the research station, average grain yield improved by 10–13% in T3 compared with T2 treatment. Depending on seasons, higher agronomic N use efficiency (19–30%), physiological N use efficiency (8–18%), partial factor productivity (PFP)N (114–150%), recovery efficiency (RE)N (3–31%), N harvest index (HIN) (14–24%), agronomic P use efficiency (22–25%), partial factor productivity of P (9–12%), AREP (15–23%), and HIP (3–6%) were obtained in T3 compared with T2 treatment. Research results were reflected in farmers’ field, and significant (P < 0.05) higher plant height, tiller, panicle, grain yield, partial factor productivity of N and P were obtained in the same treatment. Application of BoF improved soil organic carbon by 6–13%, along with an increased number of PGPB as compared with full synthetic fertilizer dose. In conclusion, tested BoF can be considered as a green technology to reduce 30% synthetic N and 100% TSP requirements in rice production with improved soil health.

Grass carp (Ctenopharyngodon idella) was cultured in the inundated low-lying coastal wetlands using Asian watergrass (Hygroryza aristata) as feed for 6 months. The study was carried out with three treatments, each with three replications. The grass was planted during plot preparation in treatment one (Grass Planted; GP); the grass was collected those grown in an adjacent land and supplied to the fish in treatment two (Grass Supplied; GS); and the fish were fed with commercial feed in treatment three (Commercial Feed; CF). Similar sized juveniles of grass carp (51 ± 6 g) were stocked at the rate of 12,500 fish ha−1 in each treatment. Important water quality parameters were measured at a monthly interval and found within the suitable range for growth of grass carp. The survival was significantly higher in GP (92.7 ± 1.0 %), followed by GS (90.0 ± 1.7 %) and CF (90.0 ± 2.9 %). The growth parameters (weight gain and specific growth rate; SGR) of fish were found significantly higher in GP, followed by CF and GS. The highest total production was found in GP (6770 ± 424 kg ha−1), followed by CF (6733 ± 536 kg ha−1) and GS (5519 ± 483 kg ha−1). The highest net economic benefit and benefit-cost ratio were found in GP (US$ 13375.50 ha−1 and 3.32) and the lowest in CF (US$ 4958.25 ha−1 and 0.42). The results of the present study indicate that Asian watergrass can successfully be used in commercial culture of grass carp and it may significantly reduce the production cost.

Graphical abstract, Highlights • Effects of fenitrothion on community level and functional endpoints of freshwater ecosystems in microcosms were studied. • No consistent significant effects were observed for most of the phytoplankton taxa. • There was a significant decrease for most of the species composition of zooplankton and macro-invertebrates. • Several taxa were sensitive to even the lowest concentration of fenitrothion., The organophosphate pesticide fenitrothion is widely used as an agricultural pesticide to control tiger bug in larval rearing for aquaculture. The objectives of the present study were to assess the effects of fenitrothion on certain structural (phytoplankton, zooplankton, macro-invertebrates and periphyton) and functional (organic matter decomposition) endpoints of freshwater microcosms. Fenitrothion 50 EC was applied in 12 microcosms (PVC tanks having 400 L of dechlorinated tap water) providing concentrations of 0, 25, 50 and 100 μg/L at a 4-day interval over a period of 4 weeks. Each of the experimental treatment was executed in three replicates. The results indicated the consistent significant effects for most of the species composition of zooplankton and macro-invertebrates. Univariate analysis showed a significant decrease in abundance (p

Increase in water temperature due to anthropogenic and climatic changes is expected to affect physiological functions of fish. In this study, we determined high temperature tolerance (CTmax) of a common aquacultured Indian major carp, rohu, Labeo rohita fingerlings (15.96 ± 0.72 g BW, 11.56 ± 0.42 cm TL) followed by acclimatization at three temperatures (30, 33, 36 °C). To determine the CTmax, we analyzed the major hemato-biochemical indices - hemoglobin (Hb), red blood cell (RBC), white blood cell (WBC), blood glucose levels, and erythrocytic nuclear abnormalities (ENAs) and erythrocytic cellular abnormalities (ECAs) of peripheral erythrocytes in the fish sampled at the start and end point at each acclimated temperature. Significantly decreased CTmax of the fish was found at 36 °C compared to 30 °C and 33 °C. The fish in the highest (36 °C) temperature were found with significantly lower Hb and RBC content and significantly higher WBC and blood glucose levels than that of the fishes in the lowest (30 °C) temperature both at the start and end points. The highest frequencies of ENAs and ECAs were found in the highest (36 °C) temperature group compared to the lowest (30 °C) temperature group at both the points. We also evaluated growth performance of the rohu fingerlings reared in the three temperatures for 60 days. The growth parameters - final weight gain, percent weight gain and specific growth rate were the highest at 33 °C and the lowest at 36 °C. The present study revealed that the highest temperature (36 °C) tested here may be hazardous to rohu and the temperature should be kept below 36 °C in the aquaculture setting to avoid physiological damage and growth and production loss to the fish.

As a consequence of global warming, increase of water temperature is likely to alter physiological functions of fish. Hence, we examined the effects of high temperature on blood glucose, hematological parameters [hemoglobin (Hb), red blood cell (RBC), and white blood cell (WBC)], and nuclear and cellular structure of blood cells of common carp (Cyprinus carpio) after exposure to three temperature regimes (27, 31, and 35°C) for 14 days. Fish were sacrificed on 3, 7, and 14 days of exposure. The blood glucose level increased significantly in the fish exposed to 35°C compared to 27 and 31°C. The Hb and RBC contents decreased but WBC increased significantly in the blood of fish exposed to 35°C compared to 27 and 31°C at 7 and 14 days of exposure. Consequently, the frequencies of erythroblasts (Ebs), erythrocytic nuclear abnormalities (ENA), and erythrocytic cellular abnormalities (ECA) were found to be increased in the blood of fish exposed to 35°C compared to 27 and 31°C. There was a significant increase in neutrophils and decrease in lymphocytes in the highest temperature (35°C). With increasing temperature, dissolved oxygen (DO) decreased but free CO2 increased significantly during the study period. The present study demonstrated that common carp are better adapted to 27 and 31°C environmental temperatures, while the higher temperature 35°C is likely stressful to this fish species.

Global warming is a threat across the world that leads to estimates of the upper thermal limits of ectothermic species. Increased water temperature up-regulates oxygen consumption and metabolic rates, and alters the physiological processes. In this study, we identified the critical thermal maxima (CTmax) and physiological responses under normoxia and hypoxia in Nile tilapia, Oreochromis niloticus. CTmax was 41.25 °C under hypoxia and 44.50 °C under normoxia. Compared to normoxia, lower values of hemoglobin (Hb) and red blood cells (RBCs) were observed at the CTmax under hypoxia. In contrast, higher values of white blood cells (WBCs) and blood glucose (Glu) levels were observed at the CTmax under hypoxia. Consequently, higher frequencies of micronucleus, cellular and nuclear abnormalities of erythrocytes were observed at the CTmax under hypoxia. These results suggest that high temperature tolerance and subsequent physiology are significantly affected by the oxygen supply in Nile tilapia. As climate vulnerability is intensifying day by day, this data will be helpful in successful management practice for the aquatic environment having low oxygen content.

The phytosociological analysis, species diversity and types, fidelity, presence, constancy, Sørensen similarity index and changes in forest cover, land and water areas since 1972 were analyzed. Forty six species were recorded both in quadrats and growing outside which belong to 26 families and 41 genera, 19 were distinguished as true mangrove species and the rest were mangrove associates. Leguminosae and Rhizophoraceae were the dominant families represented by 5 spp. each. Three species were found to be invasive, namely Blumea lacera (Burm. F.) DC., Catharanthus roseus (L.) G. Don., Wedelia chinensis (Osbeck) Merr. The maximum importance value index was found in Heritiera fomes Buch.-Ham (48.08). The overall species diversity (H) of SMF was found 3.81, species richness (d) was 9.10 and evenness (e) was 0.47. The forest area was 385,237 ha in 2015. The satellite images showed that the forest and water area of SMF decreased gradually till 2015 in comparison to 1972. The bare land of Sundarbans showed a significantly increasing trend till 2015 since 1972.

The study was carried out to determine the effect of temperature changes on acute toxicity of pyrethroid pesticide cypermethrin in zebrafish. A two-day renewal bioassay system for 96h was conducted to find out LC50 value of cypermethrin at two temperature regimes i.e. 25°C and 30°C considering as T1 and T2, respectively. During the determination of LC50 in both temperatures, blood glucose (mg/dL) levels were measured at lower concentration (0.25 µg/L) of cypermethrin. The results of acute toxicity test at 96h LC50 values were calculated through probit analysis. It was found that 96h LC50 for T1 and T2 groups were about 2.1 and 1.4 µg/L, respectively. Significantly lower LC50 of cypermethrin at T2 compared to T1 showed that higher temperature increased the toxicity of cypermethrin. There was a significant increase (P

Probiotics play an important role as bio-friendly substances in ensuring the sustainability and profitability of aquaculture. In the present study, we examined the effects of probiotic brewer's yeast, Saccharomyces cerevisiae on growth, feed utilization, hemato-biochemical indices, intestinal microbiota and intestinal morphometry of rohu, Labeo rohita. A trial of 90 days was conducted in which rohu fingerlings were fed under four different treatment groups in aquaria, receiving S. cerevisiae at 0, 1, 2 and 4 g/kg diet, respectively. Growth parameters (weight gain and specific growth rate), feed utilization (feed conversion ratio and protein efficiency ratio), hematobiochemical indices (hemoglobin, red blood cell, white blood cell and glucose), intestinal microbiota (total viable, lactic acid bacteria and yeast count) and intestinal morphology (villi length, villi width, crypt depth, thickness of villi wall etc.) were analyzed at the end of feeding trial. The results demonstrated substantial development in the growth performance, feed utilization and hematobiochemical indices in rohu fed probiotic incorporated diet compared to control diet. There were noticeable variations in intestinal microbiota and intestinal morphology between the treated and control diet fed groups. These results revealed that S. cerevisiae has a potential influence as an essential probiotic to improve the digestion, absorption, assimilation of nutrients through the improvement of gut microbiota and morphometry of L. rohita. Thus, S. cerevisiae can be effectively recommended as an important growth promoter for rohu.

Probiotics, an eco-friendly alternative to antibiotics application appears to have strong potential for improving the sustainability of aquaculture. The aim of the study was to evaluate the effect of probiotic brewer’s yeast, Saccharomyces cerevisiae supplementation on growth performance, feed utilization and intestinal morphometry of Nile tilapia, Oreochromis niloticus. A feeding trial of 60 days was conducted in which tilapia fingerlings (7.55 ± 1.25 g) were randomly distributed into three replicate aquaria under four different treatment groups, receiving S. cerevisiae at 0, 1, 2 and 4 g kg−1 diet, respectively. At the end of the feeding trial, growth performance parameters (weight gain, WG; % WG; specific growth rate, SGR), feed utilization indices (protein efficiency ratio, PER; feed conversion ratio, FCR) and intestinal morphology were assessed. The results obtained from this study revealed that growth performance and feed utilization indices were increased significantly in the fish fed with 4 g kg−1 S. cerevisiae supplemented diet compared to controls. The length, width and area of villus were significantly enlarged in fish fed 4 g kg−1 S. cerevisiae supplemented diet. Likewise, intestinal mucosal fold, width of lamina propria, width of enterocytes and number of goblet cells increased in the fish fed with 4 g kg−1 S. cerevisiae supplemented diet. These results demonstrated that S. cerevisiae can be effectively recommended as an important growth promoter for tilapia culture.

Water temperature alone can affect the growth, metabolic rates and physiological responses of aquatic organisms. Our earlier study reported that higher temperature affects cellular and hemato-biochemical responses in rohu, Labeo rohita. In this backdrop, the present study assessed the effect of higher acclimation temperature on the regulatory mechanisms of growth and stress responses of juvenile L. rohita acclimatized in three temperature conditions (30 °C, 33 °C, and 36 °C) for a period of 30 days. The relative expression of genes for growth hormone (GH), insulin-like growth factors (IGF-1 and IGF-2) and heat shock proteins (hsp70 and hsp90) were measured by real-time quantitative PCR. The results revealed that the highest acclimation temperature (36 °C) significantly decreased the weight gain (WG) and specific growth rate (SGR), and increased the feed conversion ratio (FCR) compared to 30 °C (control), while increased WG, SGR and lowered FCR were observed in fish reared at the intermediate temperature (33 °C) compared to 30 °C. Similarly, the GH gene expression in the pituitary was significantly decreased and increased at 36 °C and 33 °C, respectively as compared to 30 °C. A significantly lower expression of IGF-1 and IGF-2, and higher expression of hsp70 and hsp90 were observed in the liver of fish at 36 °C. The results of the present study indicate that although slightly elevated temperature promotes the growth of juvenile L. rohita, the higher acclimation temperature may induce stress response and impair growth performance by suppressing GH/IGF system.

Identification of Labeo rohita, L. bata and L. gonius is sometimes problematic when usual morphological features are lost and it is difficult to differentiate them with traditional morphological features at their diverse developmental stages. PCR-sequencing provides an authentic alternative means of identification of individuals at species level. Three local carp fishes were collected and 16S rRNA genes were sequenced by sanger sequencing method after PCR amplification using universal primers. Obtained sequences were found accurate with blast search result which showed maximum range of similarity with the existing respective gene fragments present in GenBank database. Sequences were compared and multiple sequence alignment has revealed some polymorphic sites which can be used to differentiate these three species from one another. This study may provide valuable understanding to study their population in future. Dhaka Univ. J. Biol. Sci. 26(2): 167-174, 2017 (July)

Pyrogen content is a key quality feature that must be checked in all injectable products, including vaccines. Four tests are currently available in the European Pharmacopoeia to monitor pyrogen/endotoxin presence: 1) the Rabbit Pyrogen Test (RPT), 2) the Bacterial Endotoxin Test, 3) the Recombinant Factor C test and the Monocyte Activation Test (MAT). Here, we explored the possibility to replace RPT with the MAT in the quality control of a vaccine against tick-borne encephalitis virus (TBEV). The testing was carried out using cryopreserved peripheral blood mononuclear cells as cellular source. IL-6 release was selected as readout for the detection of both endotoxin and non-endotoxin contaminants. MAT applicability for pyrogen testing of the TBEV vaccine was assessed through preparatory tests and resulted in the set-up of a very sensitive assay (limit of detection, LOD = 0.04 EU/ml; Sensitivity = 0.1 EU/ml). Both quantitative Method A and semi-quantitative Method B were used for data analysis. Our studies revealed that for vaccine without intrinsic pyrogenicity, as that against TBEV, sensitivity (the lowest endotoxin value of the standard curve) should be used instead of LOD in order to define a stable maximum valid dilution of the product. In conclusion, we describe the challenges of MAT implementation for anti-TBEV vaccine following the current MAT chapter 2.6.30 and propose a re-evaluation of the validity criteria of the Methods A and B, in order to set a semi-quantitative or limit test suitable for those products for which a reference lot comparison analysis is not applicable or favorable.

Rice (Oryza sativa L.) is the main food for the largest community in the world, and its demand is increasing day by day. It is a highly palatable energy-rich food as a result of its starch content. Among different parts of rice, rice bran consists of high protein and energy. Brown rice is the most nutritious and consists of different types of fat (monounsaturated, polyunsaturated, and saturated), carbohydrates, protein, fiber, vitamins, and minerals. Rice loses some nutrients during milling process. Rice quality is a general concept which covers many characteristics ranging from physical to biochemical and physiological properties of rice. The eating and cooking quality (ECQ) of the rice grain is one of the most serious factors in many rice-producing areas of the world. The ECQs are important determinants of cooked rice quality. The ECQs are composed of several physical and chemical characteristics of starch in the endosperm, viz., amylose content (AC), gel consistency (GC), viscosity, aroma, gelatinization temperature (GT), and texture of cooked rice. Aroma of cooked rice is the most important feature of high-quality rice. Fragrance of rice is a combination of more than 100 volatile compounds, and among those, one chemical, 2-acetyl-1-pyrroline (2AP), is considered as the main contributor. Choice of grain size, shape, aroma, and appearance of rice varies from one group of consumer to another.

The experiment was conducted to determine the effects of population densities of tilapia (Oreochromis niloticus) on the growth and production of tilapia in monoculture system. Fish population density was 80 fish per decimal under treatment-I, 160 fish per decimal under treatment-II and 320 fish per decimal under treatment-III. In the ponds under three treatments supplementary feed was not used. The average initial length and weight of the fry of tilapia was 4.48 cm and 0.067 g, respectively. The ponds were fertilized fortnightly with urea and TSP at the rates of 60 g, and 90 g per decimal, respectively. Mean survival rates of fish under treatment-I, treatment-II and treatment-III were 91.12%, 82.82% and 66.23%, respectively. The specific growth rates (SGR, % per day) of fish under treatment-I, treatment-II and treatment-III were 5.49%, 4.95% and 4.61%, respectively. The calculated net fish production of the ponds under treatment-I was 2.65 ton ha-1 yr-1 and that of the ponds under treatment-II was 2.55 ton ha-1 yr-1 and that of the ponds under treatment-III was 2.68 ton ha-1 yr-1. The net fish production under treatment-I and treatment-III were 2.65 ton ha-1 yr-1 and 2.68 ton ha-1 yr-1 higher than that of treatment-II, taking net fish production under treatment-I for 100%. According to survival rates and specific growth rates treatment-I is the best. So, the population density of 80 fish per decimal (under treatment-I) might be considered the best among the three treatments. Int. J. Agril. Res. Innov. Tech. 9(2): 76-83, December 2019