Search results for: Oyster larvae

Authors: Hyoun Joong Kim, Jin Woo Jun, Sib Sankar Giri, Cheng Chi, Saekil Yun, Sang Guen Kim, Sang Wha Kim, Jeong Woo Kang, Se Jin Han, Se Chang Park

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Vibrio corallilyticus is a well-known pathogen of coral. It is also infectious to a variety of shellfish species, including Pacific oyster (Crassostrea gigas) larvae. V. corallilyticus is remained to be a major constraint in marine bivalve aquaculture practice, especially in artificial seed production facility. Owing to the high mortality and contagious nature of the pathogen, large amount of antibiotics has been used for disease prevention and control. However, indiscriminate use of antibiotics may result in food and environmental pollution, and development of antibiotic resistant strains. Therefore, eco-friendly disease preventative measures are imperative for sustainable bivalve culture. The present investigation proposes the application of bacteriophage (phage) as an effective alternative method for controlling V. corallilyticus infection in marine bivalve hatcheries. Isolation of phages from sea water sample was carried out using drop or double layer agar methods. The host range, stability and morphology of the phage isolates were studied. In vivo phage efficacy to prevent V. corallilyticus infection in oyster larvae was also performed. The isolated phages, named pVco-5 and pVco-7 was classified as a podoviridae and pVco-14, was classified as a siphoviridae. Each phages were infective to four strains of seven V. corallilyticus strains tested. When oyster larvae were pre-treated with the phage before bacterial challenge, mortality of the treated oyster larvae was lower than that in the untreated control. This result suggests that each phages have the potential to be used as therapeutic agent for controlling V. corallilyticus infection in marine bivalve hatchery.

Keywords: bacteriophage, Vibrio coralliilyticus, Oyster larvae, mortality

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Authors: Fei Xu, Guofan Zhang, Xiao Liu

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Many major marine invertebrate phyla are characterized by indirect development. These animals transit from planktonic larvae to benthic adults via settlement and metamorphosis, which has many advantages for organisms to adapt marine environment. Studying the biological process of metamorphosis is thus a key to understand the origin and evolution of indirect development. Although the mechanism of metamorphosis has been largely studied on their relationships with the marine environment, microorganisms, as well as the neurohormones, little is known on the gene regulation network (GRN) during metamorphosis. We treated competent oyster pediveligers with epinephrine, which was known to be able to effectively induce oyster metamorphosis, and analyzed the dynamics of gene and proteins with transcriptomics and proteomics methods. The result indicated significant upregulation of protein synthesis system, as well as some transcription factors including Homeobox, basic helix-loop-helix, and nuclear receptors. The result suggested the GRN complexity of the transition stage during oyster metamorphosis.

Keywords: indirect development, gene regulation network, protein synthesis, transcription factors

Procedia PDF Downloads 106

Authors: Lee Sunghyoun, Yu Byeongkee, Kim Hyuckjoo, Yun Namkyu, Jung Jongcheon

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Most of the recent on-sale oyster mushrooms are raised in a oyster mushroom house, in which the necessary adjustment of growing condition is feasible. The rationale for such artificial growing is the impossibility of successive cultivation in the case of a natural cultivation due to external weather conditions. A oyster mushroom house adopts an equipment called growing bed, laying one growing bed upon another in a multi-column fashion, growing and developing the mushrooms on the respective equipments. The indispensable environment management factors of mushroom cultivation are temperature, humidity, and CO2; on which an appropriate regulation of the three requisites is a necessitated condition for the sake of the total output’s increase. However, due to the multiple layers of growing bed’s disturbance on air circulation, a oyster mushroom house’s internal environmental uniformity meets with considerable instability. This research presents a technology which assures the facilitation of environment regulation over all the internal space of a oyster mushroom house, irrespective of its location. The research staff reinforced the oyster mushroom house’s insulation in order to minimize the external environment’s influence on the oyster mushroom house’s internal environment and installed circulation fan to improve the oyster mushroom house’s interior environmental uniformity. Also, the humidifier nozzle’s position was set to prevent dew condensation when humidifying. As a result, a highly sophisticated management over all the oyster mushroom house‘s internal space was realized with the temperature of 0.2~1.3℃, and the relative humidity of 2~7% at the cultivating stage of mushroom’s growth. Therefore, to maximize oyster mushroom house‘s internal environmental uniformity, it can be concluded that consideration of various factors such as insulation reinforcement, decision on the humidifier nozzle’s location, disposition of circulation fan’s installation and the direction of wind discharge is needed.

Keywords: mushroom growing facility, environmental uniformity, temperature, relative humidity, CO2 concentration

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Authors: Yong-Kian Lim, Khan Cheung, Xin Dang, Steven Roberts, Xiaotong Wang, Vengatesen Thiyagarajan

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Unprecedented rate of increased CO₂ level in the ocean and the subsequent changes in carbonate system including decreased pH, known as ocean acidification (OA), is predicted to disrupt not only the calcification process but also several other physiological and developmental processes in a variety of marine organisms, including edible oysters. Nonetheless, not all species are vulnerable to those OA threats, e.g., some species may be able to cope with OA stress using environmentally induced modifications on gene and protein expressions. For example, external environmental stressors, including OA, can influence the addition and removal of methyl groups through epigenetic modification (e.g., DNA methylation) process to turn gene expression “on or off” as part of a rapid adaptive mechanism to cope with OA. In this study, the above hypothesis was tested through testing the effect of OA, using decreased pH 7.4 as a proxy, on the DNA methylation pattern of an endemic and a commercially important estuary oyster species, Crassostrea hongkongensis, at the time of larval habitat selection and metamorphosis. Larval growth rate did not differ between control pH 8.1 and treatment pH 7.4. The metamorphosis rate of the pediveliger larvae was higher at pH 7.4 than those in control pH 8.1; however, over one-third of the larvae raised at pH 7.4 failed to attach to an optimal substrate as defined by biofilm presence. During larval development, a total of 130 genes were differentially methylated across the two treatments. The differential methylation in the larval genes may have partially accounted for the higher metamorphosis success rate under decreased pH 7.4 but with poor substratum selection ability. Differentially methylated loci were concentrated in the exon regions and appear to be associated with cytoskeletal and signal transduction, oxidative stress, metabolic processes, and larval metamorphosis, which implies the high potential of C. hongkongensis larvae to acclimate and adapt through non-genetic ways to OA threats within a single generation.

Keywords: adaptive plasticity, DNA methylation, larval metamorphosis, ocean acidification

Procedia PDF Downloads 108

Authors: Varangkana Thaotumpitak, Jarukorn Sripradite, Saharuetai Jeamsripong

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Environmental contamination from wastewater discharges originated from anthropogenic activities introduces the accumulation of enteropathogenic bacteria in aquatic animals, especially in oysters, and in shellfish harvesting areas. The consumption of raw or partially cooked oysters can be a risk for seafood-borne diseases in human. This study aimed to evaluate the relationship between the presence of Salmonella in oyster meat samples, and environmental factors (ambient air temperature, relative humidity, gust wind speed, average wind speed, tidal condition, precipitation and season) by using the principal component analysis (PCA). One hundred and forty-four oyster meat samples were collected from four oyster harvesting areas in Phang Nga province, Thailand from March 2016 to February 2017. The prevalence of Salmonella of each site was ranged from 25.0-36.11% in oyster meat. The results of PCA showed that ambient air temperature, relative humidity, and precipitation were main factors correlated with Salmonella detection in these oysters. Positive relationship was observed between positive Salmonella in the oysters and relative humidity (PC1=0.413) and precipitation (PC1=0.607), while the negative association was found between ambient air temperature (PC1=0.338) and the presence of Salmonella in oyster samples. These results suggested that lower temperature and higher precipitation and higher relative humidity will possibly effect on Salmonella contamination of oyster meat. During the high risk period, harvesting of oysters should be prohibited to reduce pathogenic bacteria contamination and to minimize a hazard of humans from Salmonellosis.

Keywords: oyster, Phang Nga Bay, principal component analysis, Salmonella

Procedia PDF Downloads 105

Authors: A. S. El Naas, K. S. Ganghish, A. O. Booker, O. Elwaer

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10 out of 40 camels examined at Tripoli slaughter places were infected with the camel nasal bot fly Cephalopenia titillator. The larvae occurred mainly in the nasopharynx and occasionally the larvae were found embedded between turbinated bones. The nasal cavity was congested and filled with mucus in which some larvae were entangled. This work is undertaken to determine the Prevalence of Cephalopenia titillator of camel slaughtered in Tripoli-Libya.

Keywords: Cephalopenia titillator, camels, Libya, larvae, nasopharynx

Procedia PDF Downloads 390

Authors: Luz Hurtado, Rodrigo Rojas, Jaime Romero, Christopher Concha

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The culture of the marine fish red cusk eel Genypterus chilensis is currently considered a priority for Chilean aquaculture which is a Chilean native species of high gastronomic demand and market value. The microbiota was analyzed in terms of diversity and structure using massive Illumina sequencing. The analysis of alpha diversity was performed in samples of G. chilensis larvae of 6, 18 and 32 dph (days post-hatching) and it was observed that there were significant differences (P = 0.05) between the days of culture for the Chao1 index, being the larvae of 18 dph the one with the highest index followed by the larvae of 6 dph, The lowest value for this index was presented in larvae of 32 dph. There were no significant differences in larvae between the days of culture for the Shannon (P=0.0857) and Simpson (P=0.0714) indices. In general, the larvae of G. chilensis have high rates of diversity. When analyzing the beta diversity, a differentiation between the bacterial communities is observed depending on the day of the culture of the larvae. Considering the PCoA elaborated from the unweighted UniFrac statistic, the explained variance was 46.2% (PC1 29.2% and PC2 17.0%) and in the case of the PCoA elaborated with the weighted UniFrac statistic; the explained variance was 65.5% (PC1 41.8% and PC2 23.7%) these differences were significant based on the Permanova statistical analysis (P= 0.002 and 0.037 respectively). When analyzing the taxonomic composition of the microbiota of the larvae in the different days of culture it was observed that at the phyla level the most abundant in the larvae of 6 dph were Proteobacteria (57%) Verrucomicrobia (24%) and Firmicutes (14%), for the larvae of 18 dph the predominant phyla were Proteobacteria (90%), Dependientiae (5%), Actinobacteria (2%) and Plactomyces (2%), for the larvae of 32 dph the phyla that presented the highest relative abundance were Proteobacteria (57%), Firmicutes (29%), Verrucomicrobia (5%) and Actinobacteria (5%), when comparing the larvae between the days it was observed that the phylum Proteobacteria was the most abundant in the samples of larvae of 6, 18 and 32 dph being the larvae of 18 dph those that present the highest relative abundance, the larvae of 6 dph were those that presented the highest relative abundance for the phylum Verrucomicrobia and in the larvae of 32 dph was observed greater abundance of the phylum Firmicutes compared to the other days of larval culture. At the level of genera, those with the highest relative abundance in larvae of 6 dph were Rubritalea (30%), Psychrobacter (28%), staphylococcus (17%) and Ralstonia (10%), for the larvae of 18 dph the genera with the highest abundance were Psychrobacter (47%), Litoreibacter (13%), Nautella (9%) and Cohesibacter (8%), for the larvae of 32 dph the most abundant genera were Alloiococcus (25%), Dialister (14%), Neptunomonas (13%) and Piscirickettsia (11%). When observing the taxonomic composition of the larvae between the days of larval culture, it is observed that there are differences between them.

Keywords: microbiota, diversity, G. Chilensis, larvae

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Authors: Futo Asano, Yusuke Yatsushiro, Hirokuni Miyamoto, Hiroaki Kodama

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A thermophile-fermented compost is produced using small fishes, crabs, and shrimps under a high temperature (approximately 75℃) by fermentation-associated self-heating. This compost has been used as a feed additive for pigs and hens in Japan, and the fecundity of this livestock is enhanced. Firmicutes is a dominant phylum in the microbial composition of the compost. We first reported that improvement of female larval fitness of Hercules beetle can be achieved by amendment of this compost to the humus. When the 90-d-old larvae were reared for subsequent 72 days in the humus with this compost, the growth of female larvae was significantly enhanced when compared with the growth of female larvae in the humus without the compost. In contrast, the growth of male larvae in the compost-free humus was the same as the larvae grow in the compost-amended humus. The bacterial composition of the feces of larvae was determined at 0 days and 46 days after transfer to the humus with or without the compost. The most dominant bacterium in the feces was Xylanimonas. Interestingly, the growth improvement of female larvae was associated with an increased abundance of Mollicutes in the fecal samples. These results indicate that the compost act as a probiotic material for enhancing the female larvae growth by supporting Mollicutes. Here, we tried to isolate Mollicutes from the contents of the midgut and hindgut of the 3rd instar female larvae of the Hercules beetle. These gut contents were spread onto a selective agar medium for Mollicutes (PPLO agar broth, BD Difco, NJ, USA). Although we isolated none of the Mollicutes until now, several bacteria that are closely related to Xylanimonas and Luteimicrobium were isolated. These isolates have xylanase and glucanase (CMCase) activities. We show the gut bacterial profiles of larvae and discuss how the fitness of female larvae of the Hercules beetle is improved by the compost.

Keywords: compost, beetle, mollicutes, woody biomass

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Authors: N. Adjlane, N. Haddad

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The American foulbrood is one of the most serious diseases that may affect brood of larvae and pupae stages. The causative organism is a gram positive bacterium Paaenibacillus larvae. American foulbrood infected apiaries suffer from severe economic losses, resulting from significant decreases in honeybee populations and honey production. The aim of this study was to detect Paenibacillus larvae in the remains collected at the bottom of the hive from the suspected hives by direct PCR and culture growth. A total of 56 suspected beehive wax debris samples collected in 40 different apiaries located in the central region of Algeria. MYPGP the culture medium is used during all the identifications of the bacterium. After positive results on samples, biochemical confirmation tests (test of catalase, presence hydrolysis of casein) and microscopic (gram stain) are used in order to verify the accuracy of the initial results. The QIAamp DNA Mini Kit is used to identify the DNA of Paaenibacillus larvae. Paaenibacillus larvae were identified in 14 samples out of 16 by the PCR. A suspected culture-negative sample was found positive through evaluation with PCR. This research is for the bacterium Paaenibacillus larvae in the debris of the colony is an effective method for diagnosis of the pathology of American foulbrood.

Keywords: Paenibacillus larvae, honeybee, PCR, microbiological method

Procedia PDF Downloads 378

Authors: RuiJin Zhang, HengJiang Cai, JinSong Gui

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It takes Patinopecten yessoensis larvae more than 20 days from spawning to settlement. Due to the natural environmental factors such as current, Patinopecten yessoensis larvae are transported to a distance more than hundreds of kilometers, leading to a high instability of their spatial and temporal distribution and great difficulties in the natural spat collection. Therefore predicting the distribution is of great significance to improve the operating efficiency of the collecting. Hydrodynamic model of Northern China Yellow Sea was established and the motions equations of physical oceanography and verified by the tidal harmonic constants and the measured data velocities of Dalian Bay. According to the passivity drift characteristics of the larvae, combined with the hydrodynamic model and the particle tracking model, the spatial and temporal distribution prediction model was established and the spatial and temporal distribution of the larvae under the influence of flow and wind were simulated. It can be concluded from the model results: ocean currents have greatest impacts on the passive drift path and diffusion of Patinopecten yessoensis larvae; the impact of wind is also important, which changed the direction and speed of the drift. Patinopecten yessoensis larvae were generated in the sea along Zhangzi Island and Guanglu-Dachangshan Island, but after two months, with the impact of wind and currents, the larvae appeared in the west of Dalian and the southern of Lvshun, and even in Bohai Bay. The model results are consistent with the relevant literature on qualitative analysis, and this conclusion explains where the larvae come from in the perspective of numerical simulation.

Keywords: numerical simulation, Patinopecten yessoensis larvae, predicting model, spatial and temporal distribution

Procedia PDF Downloads 261

Authors: Tahammal Hussain, Khuram Zia, Mumammad Jalal Arif, Megha Parajulee, Abdul Hakeem

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The Bioassay on neonate, 2nd and 3rd instar larvae of Helicoverpa armigera (Hubner) were conducted against Bacillus thuringiensis proteins Cry1Ac. Cry1Ac was incorporated into an artificial diet and was serially diluted with distilled water and then mixed with diet at an appropriate temperature of diet. Toxins incorporated prepared diet was poured into Petri-dishes. For controls, distilled water was mixed with the diet. Five toxin doses 0.25, 0.5, 1, 2, and 4 ug / ml and one control were used for each instars of H. armigera 20 larvae were used in each replication and each treatment is replicated four times. LC50 of Cry1Ac against neonate, 2nd and 3rd instar larvae of H. armigera were 0.34, 0.81 and 1.46 ug / ml. So Cry1Ac is more effective against neonate larvae of H .armigera as compared to 2nd and 3rd instar larvae under laboratory conditions.

Keywords: B. thuringiensis, Cry1Ac, H. armigera, toxicity

Procedia PDF Downloads 378

Authors: Sunghyoun Lee, Byeongkee Yu, Chanjung Lee, Yeongtaek Lim

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Oyster mushrooms are one of the ingredients that Koreans prefer. The oyster mushroom cultivation house has multiple layers in order to increase the mushroom production per unit area. However, the growing shelves in the house act as obstacles and hinder the circulation of the interior air, which leads to the difference of cultivation environment between the upper part and lower part of the growing shelves. Due to this difference of environments, growth distinction occurs according to the area of the growing shelves. It is known that minute air circulation around the mushroom cap facilitates the metabolism of mushrooms and improves its quality. This study has utilized the computational fluid dynamics (CFD) program, that is, FLUENT R16, in order to analyze the improvement of the internal environment uniformity of the oyster mushroom cultivation house. The analyzed factors are velocity distribution, temperature distribution, and humidity distribution. In order to maintain the internal environment uniformity of the oyster mushroom cultivation house, it appeared that installing circulation fan at the upper part of the working passage towards the ceiling is effective. When all the environmental control equipment – unit cooler, inlet fan, outlet fan, air circulation fan, and humidifier - operated simultaneously, the RMS figure on the growing shelves appeared as follows: velocity 28.23%, temperature 30.47%, humidity 7.88%. However, when only unit cooler and air circulation fan operated, the RMS figure on the growing shelves appeared as follows: velocity 22.28%, temperature 0.87%, humidity 0.82%. Therefore, in order to maintain the internal environment uniformity of the mushroom cultivation house, reducing the overall operating time of inlet fan, outlet fan, and humidifier is needed, and managing the internal environment with unit cooler and air circulation fan appropriately is essential.

Keywords: air circulation fan, computational fluid dynamics, multi-layered shelves cultivation, oyster mushroom cultivation house

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Authors: Irma Andriani, Ita Djuwita, Komar Sumantadinata, Alimuddin

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The recent study has been conducted to develop testicular germ cell transplantation as a tool for preservation and propagation of male germ-plasm from endangered fish species, as well as to produce surrogate broodstock of commercially valuable fish. Giant gourami testis had been used as a model for donor and Nile tilapia larvae as recipient. We developed testicular cell xenotransplantation by optimizing the timing of intraperitoneal cell transplantation to recipient larvae aged 1, 3, 5 and 7 days post hatching (dph). Freshly isolated testis of giant gourami weighing 600–800 g were minced in dissociation medium and then incubated for 3 hours in room temperature to collect monodisperce cell suspension. Donor cells labeled with PKH 26 were transplanted into the peritoneal cavity of Nile tilapia larvae using glass micropipettes. Parameters observed were survival rate of Nile tilapia larvae at 24 hours post transplantation (pt) and colonization efficiency of donor cells at 2 and 3 months pt. The incorporated donor cells were observed under fluorescent microscope. The result showed that the lowest survival rate at 24 hours pt was 1 dph larvae (82.74±6.76%) and the highest survival rate were 3 and 5 dph larvae (95.00±5.00% and 95.00±2.50%, respectively). The highest colonization efficiency was on 3 dph larvae (61.1±34.71%) and the lowest colonization efficiency was on 7 dph larvae (19.43±17.33%). In conclusion, 3 dph Nile tilapia larvae was the best recipient for giant gourami testicular germ cells xenotransplantation.

Keywords: xenotransplantation, testicular germ cell, giant gourami, Nile tilapia, colonization efficiency

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Authors: Fumiko Kojima, Shuji Fujimoto

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Anisakiasis is a disease caused by infection with an anisakid larvae, mostly Anisakis simplex. The larvae commonly infect in marine fish and the disease is frequently reported in areas of the world where fish is consumed raw, lightly pickled or salted. In Japan, people have the habit of eating raw fish such as ‘sushi’ or ‘sashimi’, so they have more chance of infection with larvae of anisakid nematodes. There are three sibling species in A. simplex larvae, namely, A. simplex sensu stricto (Asss), A. pegreffii (Ap) and A. simplex C. It was revealed that Ap is dominant among the larvae from fish (Scomber japonics) in the Japan Sea side and Asss is dominant among those of the Pacific Ocean side conversely. Although anisakiasis has happened in Japan among both the Japan Sea side area and the Pacific Ocean side area. The aim of this study was to investigate genetic variations between the siblings (Asss and Ap) and within the same sibling species by random amplified polymorphic DNA (RAPD) technique. In order to investigate the genetic difference among the each A. simplex larvae, we used RAPD technique to differentiate individuals of A. simplex obtained from Scomber japonics fish those were caught in the Japan sea (Goto Islands in Nagasaki Prefecture) and the cost of Pacific Ocean (Kanagawa Prefecture). The RAPD patterns of the control DNA (Genus Raphidascaris) were markedly different from those of the A. simplex. There were differences in amplification patterns between Asss and Ap. The RAPD patterns for larvae obtained from fish of the same sea were somewhat different and variations were detected even among larvae from the same fish. These results suggest the considerable high genetic variability between Asss and Ap and the possible existence of genetic variation within the sibling species.

Keywords: Anisakiasis in Japan, Anisakis simplex, genomic identification, PCR-RAPD

Procedia PDF Downloads 153

Authors: R. O. B. Bitencourt, F. S. Farias, M. C. Freitas, C. J. R. Balduino, E.S. Mesquita, A. R. C. Corval, P. S. Gôlo, E. G. Pontes, V. R. E. P. Bittencourt, I. C. Angelo

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Aedes aegypti larval survival rate was assessed after exposure to blastopores or conidia (mineral oil-in-water formulation or aqueous suspension) of Beauveria bassiana CG 479 propagules (blastospores or conidia). Here, mineral oil was used in the fungal formulation to control Aedes aegypti larvae. 1%, 0.5% or 0.1% mineral oil-in-water solutions were used to evaluate mineral oil toxicity for mosquito larvae. In the oil toxicity test, 0.1% mineral oil solution reduced only 4.5% larval survival; accordingly, this concentration was chosen for fungal oil-in-water formulations. Aqueous suspensions were prepared using 0.01% Tween 80^® in sterile dechlorinated water. A. aegypti larvae (L₂) were exposed in aqueous suspensions or mineral oil-in-water fungal formulations at 1×107 propagules mL^-1; the survival rate (assessed daily, for 7 days) and the median survival time (S₅₀) were calculated. Seven days after the treatment, mosquito larvae survival rates were 8.56%, 16.22%, 58%, and 42.56% after exposure to oil-in-water blastospores, oil-in-water conidia, blastospores aqueous suspension and conidia aqueous suspension (respectively). Larvae exposed to 0.01% Tween 80^® had 100% survival rate and the ones treated with 0.1% mineral oil-in-water had 95.11% survival rate. Larvae treated with conidia (regardless the presence of oil) or treated with blastospores formulation had survival median time (S₅₀) ranging from one to two days. S₅₀ was not determined (ND) when larvae were exposed to blastospores aqueous suspension, 0.01% Tween 80^® (aqueous control) or 0.1% mineral oil-in-water formulation (oil control). B. bassiana conidia and blastospores (mineral oil-in-water formulated or suspended in water) had potential to control A. aegypti mosquito larvae, despite mineral oil-in-water formulation yielded better results in comparison to aqueous suspensions. Here, B. bassiana CG 479 isolate is suggested as a potential biocontrol agent of A. aegypti mosquito larvae.

Keywords: blastospores, formulation, mosquitoes, conidia

Procedia PDF Downloads 157

Authors: Yussif Tawfiq, Stephen Omari, Kwaku Poku Asante

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The abundance of malaria vectors is influenced by micro-ecology, rainfall, and temperature patterns. The main objective of the study was to identify mosquito larval sites for future larval surveys and possible intervention programs. The study was conducted in Kintampo in central Ghana. Twenty larval sites were surveyed. Larval density was determined per cm² of water from each of the various sites. The dipper was used to fetch larvae from the larval sites, and a global positioning system (GPS) was used to identify larvae locations. There was a negative linear relationship between humidity, temperature, pH, and mosquito larval density. GPS of larval sites was taken for easy larval identification. There was the presence of Anopheles mosquito larvae in all polluted waters with Culex larval presence. This shows that Anopheles mosquito larvae are beginning to adapt to survival in polluted waters. The identified breeding sites are going to be useful for future larval surveys and will also help in intervention programs.

Keywords: larvae, GPS, dipper, larval density

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Authors: Mohaddeseh Ahmadnezhad, Shahrbano Oryan, Mahmoud Bahmani, Mohammadd Sayad Bourani

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Changes in abundance and size of skin ionocytes were investigated in two larval stage of Caspian sea zander, Sander lucioperca, before and after yolk sac absorption, at 96h after transfer from fresh water (FW; <0.5‰) to 7‰ (estuary) and 12‰ (Caspian sea water=CW) salinity. Survival rate in the stage of after yolk sac absorption were more than larval pre-absorbed yolk sac in condition of salinity (p<0.05). Ionocyte abundance increased significantly in 7 and 12‰ salinity (p<0.05), but not about ionocyte size. The results of this study suggest that development of skin Ionocyte osmoregulatory function and osmoregulation capability of Caspian Sea zander larvae increased with growth of the larvae.

Keywords: Caspian Sea, larvae, Sander lucioperca, salinity, skin ionocyte

Procedia PDF Downloads 265

Authors: Zahra Khoshnood, Reza Khoshnood

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Pesticides and drugs used in agriculture and veterinary medicine may end up in aquatic environments and bio-accumulate in the food chain, thus causing serious problems for fauna and human health. For determination of the toxic effects of atrazine herbicide on Caspian kutum, Rutilus frisii kutum larvae, the 96-h LC50 of atrazine was measured for newly hatched larvae as 18.53 ppm. Toxicity of atrazine herbicide on Caspian kutum larvae was investigated using concentrations: 9.25 ppm, 4.62 ppm and 2.31 ppm for 7 days. Comparison of the length, weight and condition factor showed that no significant differences between atrazine exposed and control groups. The concentration of Na+, K+, Ca2+, Mg2+, and Cl- in whole body of larvae in control and atrazine exposure groups were measured and the results showed that concentrations of all these ions is higher in atrazine exposure group than control group. It is obvious from this study that atrazine negatively affects osmoregulation process and changes ion compositions of the body even at sub-lethal concentration and acute exposure but have no effects on growth parameters of the body.

Keywords: atrazine, caspian kutum, acute toxicity, body ions, lc50

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Authors: Z. Khoshnood, L. Khoshnood

Abstract:

Pesticides and drugs used in agriculture and veterinary medicine may end up in aquatic environments and bioaccumulate in the food chain, thus causing serious problems for fauna and human health. For determination of the toxic effects of atrazine herbicide on Caspian kutum, Rutilus frisii kutum larvae, the 96-h LC50 of atrazine was measured for newly hatched larvae as 18.53 ppm. Toxicity of atrazine herbicide on Caspian kutum larvae was investigated using concentrations: 9.25 ppm, 4.62 ppm and 2.31 ppm for 7 days. Comparison of the length, weight, and condition factor showed that no significant differences between atrazine exposed and control groups. The concentration of Na+, K+, Ca2+, Mg2+ and Cl- in whole body of larvae in control and atrazine exposure groups were measured and the results showed that concentrations of all these ions is higher in atrazine exposure group than control group. It is obvious from this study that atrazine negatively affects osmoregulation process and changes ion compositions of the body even at sublethal concentration and acute exposure but have no effects on growth parameters of the body.

Keywords: atrazine, Caspian Kutum, acute toxicity, body ions, LC50

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Authors: Ahmed El-Sabbagh, Heba Mansour, Magdy El-Hedeny

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This study provided a taphonomic alteration and paleoecology of Cenomanian oysters from the Musabaa Salama area, south western Sinai, Egypt. Three oyster zones can be recognized in the studied area, a lower one of Amphidonte (Ceratostreon) flabellatum (lower-middle Cenomanian), a middle zone of Ilymatogyra (Afrogyra) africana (upper Cenomanian) and an upper one of Exogyra (Costagyra) olisiponensis (upper Cenomanian). Taphonomic features including disarticulation, fragmentation, encrustation and bioerosion were subjected to multivariate statistical analyses. The analyses showed that the distributions of the identified ichnospecies were greatly similar within the identified oyster zones in the Musabaa Salama section. With rare exceptions, Entobia cretacea, Gastrochaenolites torpedo and Maeandropolydora decipiens are considered as common to abundant ichnospecies within the three recorded oyster zones. In contrast, and with some exceptions, E. ovula, E. retiformis and Rogerella pattei are considered as frequent to common ichnospecies within the identified oyster zones. Other ichnospecies, including Caulostrepsis cretacea, G. orbicularis, Trypanites solitarius, E. geometrica and C. taeniola, are mostly recorded in rare to frequent occurrences. Careful investigation of these host shells and the preserved encrusters and/or bioerosion sculptures provided data concerning: 1) the substrate characteristics, 2) time of encrustation and bioerosion, 3) rate of sedimentation, 4) the planktonic productivity level, and 5) the general bathymetry and the rate of transgression across the substrate.

Keywords: oysters, Cenomanian, taphonomy, palaeoecology, Sinai, Egypt

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Authors: Eka Candra Lina, Indah Widhianingrum, Mita Eka Putri, Nur Afni Evalia, Muhammad Makky

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The emulsifiable concentrate (EC) and wettable powder (WP) of Piper aduncum and Tephrosia vogelii mixed formulations were tested for their activities in the laboratory and their effectiveness in the field against cabbage pest Plutella xyostella. Cabbage leaves soaked in six different mixed formulation concentrations were tested to 2ⁿᵈ instar larvae of P. xylostella with six replications. The observation was conducted everyday until larvae reached 4ᵗʰ instar stage. Correlation between concentration and larvae mortality was analyzed using probit (POLO-PC). The survived larvae was observed by looking at the growth and development, as well as the antifeedant effects. Field efficacy test was based on LC₉₅ value from laboratory test result. The experiment used a randomized block design with 5 treatments and 3 replications to test the populations of P. xylostella larvae and insecticide effectivity. The results showed that the EC and WP mixed formulations showed insecticidal activity against P. xylostella larvae, with LC₉₅ value of 0.35% and 0.37%, respectively. The highest antifeedant effect on EC mixed formulation was 85.01% and WP mixed formulation was 86.23%. Both mixed formulations also slowed the development of larvae when compared with control. Field effication result showed that applications of EC mixed formulation were able to restrain the population of P. xylostella, with effectivity value of 71.06%. Insecticide effectivity value of EC mixed formulation was higher than WP mixed formulation and Bacillus thuringiensis formulation.

Keywords: botanical insecticide, efficacy, emulsifiable concentrate (EC), Plutella xylostella, wettable powder (WP)

Procedia PDF Downloads 210

Authors: Antonio B.Tangayan Jr., Hershey P. Mondejar, Pet Roey Pascual, Zeam Voltaire E. Amper

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A study on in vitro larvicidal acitivity of different levels of Madre de Cacao (Gliricidia sepium) concentrated crude ethanolic extract (CCEE) against horn fly larvae (Haematobia irritans) was conducted. The air-dried leaves of Gliricidia sepium were infused in a 1:3 ratio (w/v) using ethanol as solvent and concentrated in a rotary evaporator (60°C). A total of 120 larvae of Haematobia irritans were exposed in various concentration: 200, 400, 800 and 1000 ppm. Based on the result after 5 hours of exposure, CCE G. sepium extract at 200 ppm showed less effect with 30% mortality compared to 400 ppm, 800 ppm and 1000 ppm with 70%, 83%, and 100% mortality, respectively. Findings also revealed that CCE of G. sepium extract at 1000 ppm, 800 ppm, and commercial larvicide were comparable in causing mortality of H. irritans larvae from the first hour up to the fifth hours of exposure. However, on the fifth hour, 400 ppm was also found to be effective. This suggests that the higher the concentration of CCE G. sepium extract and the longer the time of exposure, the higher is the percentage mortality of the larvae. Thus, CCE G. sepium extract can be used as an alternative for commercial larvicide.

Keywords: horn fly, in vitro, larvicidal, Madre de Cacao

Procedia PDF Downloads 253

Authors: Waleed S. Alwaneen

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In many countries, cow dung is used as farm manure and for biogas production. Several bacterial strains associated with cow dung such as Campylobacter, Salmonella sp. and Escherichia coli cause serious human diseases. The objective of the present study was to investigate the use of insect larvae including fruit beetle, waxworms and tiger worms to improve the breakdown of agricultural wastes and reduce their pathogen loads. Fresh cow faeces were collected from a cattle farm and distributed into plastic boxes (100 g/box). Each box was provided with 10 larvae of fruit beetle, Waxworms and Tiger worms, respectively. There were 3 replicates in each treatment including the control. Bacteria were isolated weekly from both control and cow faeces to which larvae were added to determine the bacterial populations. Results revealed that the bacterial load was higher in the cow faeces treated with fruit beetles than in the control, while the bacterial load was lower in the cow faeces treated with waxworms and tiger worms than in the control. The activities of the fruit beetle larvae led to the cow faeces being liquefied which provided a more conducive growing media for bacteria. Therefore, higher bacterial load in the cow faeces treated with fruit beetle might be attributed to the liquefaction of cow faeces.

Keywords: fruit beetle, waxworms, tiger worms, waste conditioning, composting

Procedia PDF Downloads 222

Authors: Adam Musa Adam Eissa

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Environmental and weather changes especially rainfall affects the distribution and densities of mosquitoes. This work was carried out to study the distribution and densities of mosquitoes adults and larvae in a total of five selected stations in El Obied Town. A cross-sectional survey of Anopheline mosquito larval habitats was conducted. The survey was conducted during the dry season (January 2013). Larvae were collected by using the standard dipping technique, while adult stages were collected by rearing larvae in cage, because the density of adults Anopheles mosquito per room was zero by using spray sheet method by using Permethrin pesticide 25%E.C, during the study period. The results revealed that (2347) Anopheline mosquito larvae were found and collected from only one station. All of which (2347) larvae (100%) were classified as probably Anopheles Squamosus. The study also showed that, a number of 81 adults (100%) Anopheline mosquito were classified as probably Anopheles Squamosus. Anopheles Squamosus were found only in the shallow pond water habitat in Alrahma west area of El Obied, the mean Anopheline density in the study area for larvae was 0.313 per dip while the mean density of adult was 0 per room. The high mosquito larval density in Alrahma west area indicated that, this part of El Obied Town is at risk of mosquito-borne diseases including malaria. This study recommended to apply the control program against mosquito at this part of the Town.

Keywords: anopheles, squamosus, Alrahma, distribution

Procedia PDF Downloads 247

Authors: Ridwaan N. Milase, Leonardo J. Van Zyl, Marla Trindade

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American foulbrood (AFB) is the world’s most devastating honeybee disease that has drastically reduced the population of Apis mellifera capensis since 2009. The outbreak has jeopardized the South African bee keeping industry as well as the agricultural sector dependent on honeybees for honey production and pollination, leading to significant economic losses. AFB is caused by Paenibacillus larvae, a spore-forming, Gram positive facultative anaerobic and flagellated bacterium. The use of antibiotics within beehives has selected for resistant strains of P. larvae, while the current practice of burning spore contaminated beehives and equipment contributes to the economic losses in the honeybee-keeping industry. Therefore, phage therapy is proposed as a promising alternative to combat P. larvae strains affecting A. mellifera capensis. The genomes of two P. larvae strains isolated from infected combs in the Western Cape have been sequenced and annotated using bioinformatics tools. Genome analyses has revealed that these P. larvae strains are lysogens to more than 6 different prophages and possess different type of clustered regularly interspaced short palindromic repeat (CRISPRs) regions per strain. Active prophages from one of the two P. larvae strains were detected and identified using PCR. Electron microscopy was used to determine the family of the identified active prophages. Lytic bacteriophages that specifically target the two P. larvae strains were purified from sewage wastewater, beehive materials, and soil samples to investigate their potential development as anti-P. larvae agents. Another alternative treatment being investigated is the development of a prophage endolysin cocktail. Endolysin genes of the prophages have been targeted, cloned and expressed in Escherichia coli. The heterologously expressed endolysins have been purified and are currently being assessed for their lytic activity against P. larvae strains and other commensal microorganisms that compose the honeybee larvae microbiota. The study has shown that phage therapy and endolysins have a great potential as alternative control methods for AFB disease affecting A. mellifera capensis.

Keywords: American foulbrood, bacteriophage, honeybee, Paenibacillus larvae

Procedia PDF Downloads 149

Authors: A. A. El Maghrbi

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The control of vectors like mosquitoes based on the application of chemical insecticides but due to its adverse effect on the environment, and development of resistance by most of species of mosquitoes including vectors of important diseases. Ethanol and acetone extracts of nine species of plants (Allium tuberosum, Apium leptophylum, Carica papaya, Cymbopogon citratus, Euphorbia cotinofolia, Melia azedarach, Ocimum canum, Ricinus common, and Tagetes erecta) were tested in respect of their influence on the eggs and larvae of Culex quinquifasciatus in concentration 100, 10 and 1 mg/L. In relation to the survival of larvae, ethanol extract of O. canum and acetone extract of A.tuberosum in 100 mg/L have larvicide activity against L4 of Cx. quinquifasciatus. For hatching of eggs, ethanol and acetone extract of A.tuberosum (100 and 10 mg/L) and acetone extract of C.citratus (100 mg/L) produced reduction in the number of eggs hatched of Cx. quinquifasciatus. Our results indicate that each extract of the plant have potential to control mosquito population and suggest that further studies are needed in this field.

Keywords: Cx. quinquefasciatus, plant extract, ethanol, acetone, larvae, eggs

Procedia PDF Downloads 327

Authors: Fatima Huda Hallak

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The current study aimed to evaluate the activity of bacterial insecticide Vertinic against the second star larvae of Trogoderma granarium (Everts) by four treatments: A, B, C, D, at seven concentrations: 0.001, 0.01, 0.1,1,10,100,1000 PPM. The mortality rate of larvae was 100% at concentrations 10 and 100 in treatments A and B after 24 hours and after 48 hours in treatment D at 1 PPM. The efficiency of treatment A was greater as compared to treatment B at all concentrations and all exposure times. The efficiency of treatment D was greater as compared to treatment C; for example, at 0.001, 0.01, 0.1, 1 PPM, after 120 hours, the Mortality rate of larve was 6.76, 13.33, 43.33, 100% in treatment D, which it was 0.00, 0.00, 23.33, 96.67%, respectively in the treatment C.

Keywords: bacterial insecticide, trogoderma granarium (everts), fourth star larvae, vertimic

Procedia PDF Downloads 12

Authors: C. G. Sawant, C. S. Patil

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The investigation was conducted during January 2016 on Farmer’s field at Nandur Madhyameshwar, Tq. Niphad, Dist. Nashik (Maharashtra: India) on bio-efficacy of newer insecticides against Plutella xylostella L. infesting cabbage. The cabbage crop (var. Saint) was raised according to package of practices except for plant protection measures. Six newer insecticides along with two conventional insecticides and one synthetic pyrethroid were applied twice at 30 and 55 days after transplanting. Insecticidal solutions were diluted in water (375-500 L ha-1) and applied using knapsack sprayer (16L) with hollow cone nozzle. Treatments included indoxacarb @ 40 g a.i.ha-1, spinosad @ 17.5 g a.i.ha-1, flubendiamide @18.24 g a.i. ha-1, diafenthiuron @ 300 g a. i. ha-1, emamectin benzoate @ 10 g a. i. ha-1, chlorantraniliprole @ 10 g a. i. ha-1, quinalphos @ 250 g a. i. ha-1, triazophos @ 500 g a. i. ha-1, bifenthrin @ 50 g a.i. ha-1 and untreated control. The larvae were counted on head and outside the head. Observations were recorded one day before spray (Precount) and 1,3,7,14 days after spray. Results revealed that all the insecticidal treatments were significantly superior over untreated control by recording lower larval count. Among the insecticidal treatments, significantly lowest number of larvae of diamondback moth was recorded in chlorantraniliprole @ 10 g a.i.ha-1 (1.00 larvae plant-1) followed by spinosad @ 17.5 g a.i. ha-1 (1.45 larvae plant-1 and flubendiamide 18.24 g a.i. ha-1(1.53 larvae plant-1). The efficacy of insecticides reflected on yield of marketable cabbage heads by recording 242.27 qt ha-1 (1:33.38) in the treatment of chlorantraniliprole @ 10 g a.i.ha-1. It was followed by spinosad @ 17.5 g a.i. ha-1 with 236.91 qt ha-1 (1:24.92) and flubendiamide 18.24 g a.i. ha-1 with 228.49 qt ha-1 (1:30.43).

Keywords: bio-efficacy, cabbage, chlorantraniliprole, Plutella xylostella L.

Procedia PDF Downloads 116

Authors: Arianne V. Julian, Michael R. Umagat, Renato G. Reyes

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Pleurotus ostreatus, which is one of the most widely cultivated mushrooms, is an excellent source of protein and other minerals but inherently contains low calcium level. Calcium plays several vital functions in human health; therefore, adequate daily intake is necessary. Supplementation of growth substrate is a significant approach in mushroom production to improve nutritional content and yield. This study focused on the influence of varying concentrations of Ca supplementation derived from natural sources including agricultural lime, eggshell and oyster shell in rice straw-based formulation for the production of P. ostreatus. The effect of Ca supplementation on the total yield and Ca content were obtained. Results revealed that these natural sources increased both the yield and Ca of P. ostreatus. Mushroom grown in substrate with 8-10% agricultural lime and 6% eggshell powder produced the highest yields while using oyster shell powder did not vary with the control. Meanwhile, substrate supplementation using agricultural lime and eggshell powder in all concentrations have increased Ca in fruiting bodies. However, Ca was not absorbed in the oyster shell powder-supplemented substrate. These findings imply the potential of agricultural lime and eggshell powder in the production of Ca-enriched mushrooms resulting in higher yield.

Keywords: calcium fortification, mushroom production, natural sources, Pleurotus ostreatus

Procedia PDF Downloads 145

Authors: Muhammad Anjum Aqueel, Zaighum Abbas, Mubasshir Sohail, Muhammad Abubakar, Hafiz Khurram Shurjeel, Abu Bakar Muhammad Raza, Muhammad Afzal, Sami Ullah

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Keeping in view the increasing demand, queen of Apis mellifera L. (Hymenoptera: Apidae) was reared artificially in this experiment at varying diets including royal jelly. Larval duration, pupal duration, weight, and size of pupae were evaluated at different diets including royal jelly. Queen larvae were raised by Doo Little grafting method. Four different diets were mixed with royal jelly and applied to larvae. Fructose, sugar, yeast, and honey were provided to rearing queen larvae along with same amount of royal jelly. Larval and pupal duration were longest (6.15 and 7.5 days, respectively) at yeast and shortest on honey (5.05 and 7.02 days, respectively). Heavier and bigger pupae were recorded on yeast (168.14 mg and 1.76 cm, respectively) followed by diets having sugar and honey. Due to production of heavier and bigger pupae, yeast was considered as best artificial diet for the growing queen larvae. So, in the second part of experiment, different amounts of yeast were provided to growing larvae along with fixed amount (0.5 g) of royal jelly. Survival rates of the larvae and queen bee were 70% and 40% in the 4-g food, 86.7% and 53.3% in the 6-g food, and 76.7% and 50% in the 8-g food. Weight of adult queen bee (1.459±0.191 g) and the number of ovarioles (41.7±21.3) were highest at 8 g of food. Results of this study are helpful for bee-keepers in producing fitter queen bees.

Keywords: apis melifera l, dietary effect, survival and development, honey bee queen

Procedia PDF Downloads 446