Occurrence and histopathology of Ascocotyle tenuicollis metacercaria in gill of platyfish (Xiphophorus maculatus) imported to Iran

The objective of this study was to determine the prevalence of metacercarial infection in plathyfish imported to Iran. A total of 100 imported live common platyfish (Xiphophorus maculatus) from approximately 24 shipments were collected from a quarantine facility in Iran in 2007 and examined in our veterinary laboratory. Among 800 examined gill arches about 1300 cysts were found in different locations of gill filaments and were identified as a heterophyid parasite metacercaria Ascocotyle (Ascocotyle) tenuicollis Price, 1935. The prevalence of this parasite was 58%, the maximum and minimum quantity of metacercarial cysts per infected platyfish were 70 and 10, respectively. The adult worms are non-pathogenic and are intestinal parasites of piscivorous birds (e.g. Heron and Egret) and mammals. The first intermediate hosts are snails and the second intermediate hosts are centrarchiid, cyprinodontid, mugilid, and poeciliid fishes. Histopathologic examination of the infected fish gills revealed cartilage proliferation around metacercarial cysts, hyperplasia, hypertrophy and fusion in the affected gill filaments. To our knowledge, this is the first report of infection with Ascocotyle tenuicollis in the imported platyfish in Iran

Effects of Zataria multiflora and Eucalyptus globolus essential oils on haematological parameters and respiratory burst activity in Cyprinus carpio

The present study was undertaken to investigate the effects of Zataria multiflora and Eucalyptus globolus essential oils on some haematological parameters and respiratory burst activity in common carp (Cyprinus carpio). 260 fish (30±5g) were randomly distributed in 13 treatment groups; each one in three replicates and different doses of essential oils in 16-17ºC were administrated. The fish were sampled on day 1, 2, 8, 15 and 22 after the 8-day trial. Haematological parameters (red blood cell count, haematocrit) and respiratory burst activity were then evaluated in all treatment groups. The results suggest that essential oils especially Zataria multiflora in dietary intake significantly enhanced respiratory burst activity of blood neutrophlis (P< 0.05). Meanwhile, essential oils had moderate effects on RBC and haematocrit. Significant increases in RBC and haematocrit levels were just noted in T11 treatment group (P< 0.05). This study indicates that dietary administration of Zataria multiflora and Eucalyptus globolus essential oils could be used to promote the health status of common carp during temperature stress

Effect of Zataria multiflora Boiss essential oil on the growth of Staphylococcus aureus in the light salted fillets of silver carp (Hypophthalmichthys molitrix)

The effects of different concentrations of Zataria multiflora essential oils at concentrations of 0, 0.005, 0.015, 0.045, 0.135, 0.405 and 0.810% on the growth of Staphylococcus aureus were studied in a food model system, light salted fillets of silver carp (Hypophthalmichthys molitrix) at storage temperature of 10ºC for 21 days. The results showed that there was no significant difference in bacterial growth between samples treated with different concentrations of Z. multiflora essential oil and control group immediately post-inoculation. However, there was significant difference in growth of S. aureus between samples treated with concentration of 0.135 of Z. multiflora essential oil and control samples (P0.05) except of 1-day post-storage. The most inhibitorial effects were observed in the samples treated with 0.405% and 0.8 10% of Z. multiflora essential oil up to 9 and 12 days post- storage, respectively

Selected morpho-chemical features of hemocytes in farmed shrimp, Fenneropenaeus indicus in Iran

The aim of the present study was to determine various types of hemocytes, total and differential hemocyte count and to show some indices of phagocytosis, including percent phagocytosis and phagocytic index in Indian white shrimp, Fenneropenaeus indicus in Iranian shrimp farms. The hemolymph was extracted from the shrimps and mixed with anticoagulant. It then stained and Yeast was added as foreign particles to samples. Based on the cell size and presence of the granules and nucleocytoplasmic ratio, three major groups of hemocytes, including hyaline cells, small granular cells (SGC) and large granular cells (LGC) were identified. Hyaline cell (HC) was the smallest hemocyte. HC (hyaline cell) about was 10-15%, lower quantity in comparison to some species and those of LGC and SGC were 20-25% and 60-65%, respectively, suggesting that relative percentage of differential hemocyte count in Fenneropenaeus indicus is different from other decapods. Also, in this study, it was shown that SGH and LGH could engulf the yeast particles. In Contrast to some previous studies, no engulfment was observed by hyaline cells in vitro. In this study it was showed that there are some variations in total and differential hemocyte count compare to other species in the family of Penaeidae

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

The effect of different salinities on mortality and histopathological changes of SPF imported Litopenaeus vannamei, experimentally exposed to White Spot Virus and a new differential hemocyte staining method

Shrimp farmers have been suffering from loss of production due to White Spot Disease (WSD) in the last decades. A few studies focused on the environmental factors predisposed WSD. Our study aimed to investigate the effects of the different salinities on occurrence of WSD. The treatments were 30 ppt, 40 ppt and 50 ppt in triplicate and corresponding untreated control groups. White Spot Virus (WSV) was intramuscularly injected to the shrimp in whole treatments. PCR and histopathological findings within the measurement of some hemolymph parameters such as Differentiated Hemocyte Count (DHC), Total Hemocyte Count (THC) and Total Plasma Protein (TPP) were carried out. A positive result was observed for the occurrence of the antigen of the WSV obtained from the samples of each treatment of salinity due to the challenging treatments with the WSV. Mortality at the salinity of 30 ppt began at 72 h post inoculation as well as the salinity of 40 ppt, but at 50 ppt it started after 50 h. The Minimum and maximum count of mortality at the salinity of 30, 40 and 50 ppt were 3.5, 8.5 0.5, 4.5 and 1.5, 7.5, respectively. No mortality was observed in the untreated control groups of 30, 40 and 50 ppt during the experiment. It is concluded that the higher and the lower salinity, lesser or greater than the normal condition in exposed to WSV could lead to severe mortality of WSD

Growth performance, immune response and disease resistance of rainbow trout (Oncorhynchus mykiss) fed Thymus vulgaris essential oils

Efficacy of Thymus vulgaris essential oils was assessed on growth, immune response and disease resistance of rainbow trout (Oncorhynchus mykiss). Fish weighing 10 g were fed with dietary supplemented of the oils at 0.5, 1.0 and 2.0 ml/kg feed for 2 months. Fish fed with the oils at 0.5 ml/kg feed demonstrated a better weight gain and specific growth rate, compared to other treatments (p < .05). Fish fed with 1.0 ml the oils showed the highest up-regulation of complement component 3 (C3) and (cluster of differentiation 4) (CD4) genes expression (p < .05), while lysozyme gene expression level significantly increased in fish fed with 2.0 ml of the oils. In addition, at the end of the experiment, the expression of C3 and CD4 genes were significantly up-regulated in fish fed with 1.0 and 2.0 ml of the oils, while IL-1 ss and lysozyme genes expression levels were significantly decreased in fish fed 2.0 ml oils, towards the end of the trial (p < .05). There was a fluctuation in the levels of Alanine aminotransferase, Aspartate aminotransferase and Alkaline phosphatase in all treatments during the experiment. When treated fish were challenged with Aeromonas hydrophila, the highest survival rate was observed in 0.5 ml/kg treatment, followed by 2 and 1 mg/kg treatments. Overall, these findings demonstrated that dietary administration of T. vulgaris oils especially at 0.5 mg/kg feed can be considered as a potential component for enhancing of the growth, immune responses and disease resistance of trout against motile Aeromonas septicemia caused by A. hydrophila