Occurrence and intensity of parasites in Prussian carp, Carassius gibelio from Anzali wetland, southwest Caspian Sea

The aim of this study was to detect the occurrence of parasites in Prussian carp, Carassius gibelio as the most important alien fish in Anzali international wetland. This undesirable fish was introduced accidentally to Iran with Chinese carp fries which imported to the country during the last decades and then acceded to Anzali wetland. Today this fish has significant stocks in Anzali wetland but there have been limited studies about the parasites of this fish in Anzali wetland. During this study a total of 90 Prussian carp were collected by electrofishing and gillnets from April through July 2012. After recording biometric characteristics, common necropsy and parasitology methods were used. A total of 2715 individuals out of 11 parasite species were recovered. Parasitofauna consisted of: two protozoans, Ichthyophthirius multifiliis and Trichodina sp.; one nematode, Raphidascaris acus; one trematode, Diplostomum spathaceum; six monogeneans, Dactylogyrus formosus, Dactylogyrus dulkeiti, Dactylogyrus baueri, Dactylogyrus arquatus, Dactylogyrus inexpectatus and Gyrodactylus kobayashii; and one crustacean, copepodid stage of Lernaea cyprinacea. The monogeneans had the highest prevalence values (88.89%). The occurrence of D. inexpectatus in C. gibelio is reported for the first time in Iran

Comparison of Intelligent Systems, Artificial Neural Networks and Neural Fuzzy Model for Prediction of Gas Hydrate Formation Rate

The main objective of this study was to present a novel approach for predication of gas hydrate formation rate based on the Intelligent Systems. Using a data set including about 470 data obtained from flow tests in a mini-loop apparatus, different predictive models were developed. From the results predicted by these models, it can be pointed out that the developed models can be used as powerful tools for prediction of gas hydrate formation rate with total errors of less than 4%

Hemocytosis, a new disease in cultured shrimp, Fenneropenaeus indicus

Certain parasites can cause severe diseases in shrimp. Among these, protozoa are very important. The objective of our study was to describe the signs, prevalence, and intensity of hemocytosis, a new disease in shrimp, Fenneropenaeus indicus. The experimental design included three groups, one treatment as infected shrimp or group B and 2 controls with non-infected but exposure to White Spot Syndrome Virus (WSSV) shrimp as group A and non-infected non-exposure to WSSV shrimp as group C in triplicate. The results revealed that Hemocytosis associated with a decrease in hyalinocytes and large-granulocytes (less than 8%) and a considerable increase in semi-granulocytes in group A and B in contrast to group C that Hyalinocyte increased. This infection made the shrimp susceptible to WSSV disease. It is believed that Hemocytosis causes a condition which can result in a rapid mortality among susceptible species, F. indicus when exposure to WSSV is occurred

Effects of temperature on hematological and histopathological changes and survival rate of juvenile Fenneropenaeus vannamei experimentally challenged to White Spot Virus

Many shrimp farmers were suffering from White Spot Disease (WSD) onset in last decades. Oscillation of environmental factors could lead mortality in susceptible hosts. Our study was aimed to investigate the effect of different temperatures on juvenile Fenneropenaeus vannamei experimentally exposed to White Spot Virus (WSV). Five hundred and forty juveniles were distributed among 3 treatments in triplicates, 22, 25 and 30°C and experimentally WSV were injected in the shrimps. Our results showed mortality started at 36 h post inoculation (hpi) in the treatment at 25°C (T25), meanwhile the mean value of mortality percent at 54 hpi in T25 (71.10±17.35) showed the significant difference (p=.045) with T22 (3.33±3.33) and T30 (Not Observed, NO.). Our results suggest that in site selection, in primary stage of farm designing, water temperature at more than 29°C, should be considered as key environmental factor. This finding can lead us that why the White Spot Disease occurred with high mortality in some area when the days of shrimp culture were prolonged until mid autumn

Towards minimal models for realistic granular materials: Tomographic analysis of bidispersed assemblies of ellipsoid

In this paper, we report experimental results on granular compaction in a model system made of mono- and bidisperse ellipsoidal packings as well as sand packings with grain size polydispersity. The packings are subject to vertical tapping of varying duration (number of taps) and their internal three-dimensional structure is obtained using x-ray computed tomography. Particles positions and orientations are reconstructed and the global packing densities are computed. The analysis of the vertical and horizontal local packing fraction profiles reveal a homogeneous densification in the ellipsoidal packings, however, sand packings exhibit radial density gradient, possibly linked to the onset of convection

Adaptation, growth and survival of tilapia (Oreochromis niloticus) in Bafgh brackish water

An experiment was conducted to evaluate the possibility of adaptation, growth and survival of Nile tilapia (Oreochromis niloticus) with 0.3g initial weight and red tilapia (Oreochromis sp.) with 0.7g initial weight in underground brackish water. Fry of Nile tilapia and red tilapia imported from Indonesia and after passing larviculture (25g) were examined separately in fiber glass tank by two replicate. Fish were fed at a restricted feeding program according to standard table during the light period. The results showed that some growth factors such as final weight, final length, daily growth rate, specific growth rate and weight gain in Nile tilapia were slightly higher than red tilapia but other factors such as survival and feed conversion rate in red tilapia were slightly higher than Nile tilapia. There were no significantly differences at 99% level among these factors. Length-weight relationship equation was w = 0.012×TL3.189 in Nile tilapia and w = 0.014×TL3.119 in red tilapia (r2 = 0.99), b value were 3.189 and 3.119 respectively in Nile and red tilapia representing isometric growth. According to the reliable growth and high survival rate (98%), it seems that both Nile and red tilapia could be good candidates for rearing in brackish water condition

Pomelo, a tool for computing Generic Set Voronoi Diagrams of Aspherical Particles of Arbitrary Shape

We describe the development of a new software tool, called “Pomelo”, for the calculation of Set Voronoi diagrams. Voronoi diagrams are a spatial partition of the space around the particles into separate Voronoi cells, e.g. applicable to granular materials. A generalization of the conventional Voronoi diagram for points or monodisperse spheres is the Set Voronoi diagram, also known as navigational map or tessellation by zone of influence. In this construction, a Set Voronoi cell contains the volume that is closer to the surface of one particle than to the surface of any other particle. This is required for aspherical or polydisperse systems. Pomelo is designed to be easy to use and as generic as possible. It directly supports common particle shapes and offers a generic mode, which allows to deal with any type of particles that can be described mathematically. Pomelo can create output in different standard formats, which allows direct visualization and further processing. Finally, we describe three applications of the Set Voronoi code in granular and soft matter physics, namely the problem of packings of ellipsoidal particles with varying degrees of particle-particle friction, mechanical stable packings of tetrahedra and a model for liquid crystal systems of particles with shapes reminiscent of pears

Assessing the sustainability of Litopenaus vannamei on white spot virus vaccine and fed with yeast Sacchromayces cerevisiae and algae Gracilaria corticata in the face of white spot syndrome virus

Efficacy of G. corticata, S. cerevisiae and gamma irradiation WSSV as immunostimulants to white shrimp L. vannamei was investigated. 1200 healthy shrimp SPF L. vannamei subadult with average weight of 10±1.02 g were collected and divided to four groups. The first group (T1) fed with commercial pellet, second group (T2) fed S. cerevisiae (2 g/ Kg), third group (T3) fed G. corticata powder was mixed with shrimp feed (2 g/Kg) and fourth group (T4) fed commercial pellet and injected intramuscularly gamma irradiant WSSV (1µl/gbw). The shrimp were fed on these diets for a period of 10 days and then challenged injected with WSSV and maintained for 25 days. The control group maintained same manner but without inject with WSSV. Survival rate and immune parameters such as total hemocyte count (THC), total protein plasma (TPP), superoxide dismutase (SOD) activity, peroxidase (POD) activity and phenoloxidas activity (PO) were determined. The result indicated survival rate in shrimp group T4 was 57.05±3.52%, shrimp group T3 was 22.5±0.5% and shrimp group T2 was 15±1.05% and shrimp group T1 was 00.0±0%, respectively. The shrimp group T4 showed higher hematological data, i.e. THC, TPP, SOD, POD and PO at the end of experiment. This study showed that gamma irradiant WSSV are effective immunostimulants in shrimp L. vannamei and perform better than the G. corticata and S. cerevisiae

CFD-DEM Analysis of Particle Attrition in a Jet in a Fluidised Bed

In fluidised bed processes, the solids are in vigorous motion and thus inevitably subjected to mechanical stresses due to inter-particle and particle-wall impacts. These stresses lead to a gradual degradation of the particles by surface wear, abrasion and body fragmentation commonly termed attrition. One significant contribution of attrition comes from the air jets of the fluidised bed distributor. Particles are entrained into the air jet, where they get accelerated and impacted onto the fluidised bed particles. The jet induced attrition only affects the part of the bed which is limited by the jet length, where the mode of attrition is largely collisional. The overall jet attrition rate is therefore the result of the combination of the single particle damage and the flux of particles entering into that region. The attrition behaviour of particles in the jet region is analysed by evaluating their propensity of breakage experimentally and by simulating an air-jet in a bed of particles by CFD-DEM. The frequency of collisions and impact velocities are estimated from which the attrition due to a single air-jet is predicted