The Effects of Injected Geophyte Plant (Sternbergia candida) Extract on the Hemato-Immunological Parameters in Gilthead Seabream, Sparus aurata (L. 1758)

Abstract This study investigated effects of a geophyte plant extract (Sternbergia candida) on some hemato-immunological parameters in gilthead seabream, Sparus aurata (L. 1758). To serve this purpose, the plant was collected and extracted in ethanol solvent. A total 300 fish were used in experiment. Three groups were designed including control group, 0.5 mg/fish and 2 mg/fish and plant extract was given by intraperitoneal injection. Following injections on the 1st, 7th, 14th, 21st, 28th and 35th days, blood samples were collected from each group. Some of the hemato-immunological parameters in serum and blood samples such as, phagocytic activity (NBT (+) cells), total leukocyte level, lysozyme activity, total protein, hematocrit level and the differential leucocyte were examined. Present results show that intraperitoneal injection of S. candida plant extract increases some non-specific immune parameters. In the determination of the non-specific immune responses of the gilthead seabream, blood samples collected from 2mg/fish group indicated that maximum levels of pre-determined parameters were reached on days 7, 14, and 21 following the injection. According to these finding, administration of geophyte plant is suggested in seabream to improve non-specific immune response and health status.

Dietary olive leaf (Olea europea L.) extract alters some immune gene expression levels and disease resistance to Yersinia ruckeri infection in rainbow trout Oncorhynchus mykiss.

The aim for the present study was to investigate the effects of olive leaf (Olea europea L.) extract (OLE) on the control of Yersinia ruckeri infection in rainbow (Oncorhynchus mykiss) trout and to assess the impact on the expression of immune-related genes in the spleen and serum biochemical parameters of rainbow trout. Five experimental diets were prepared by adding 0.0%, 0.1%, 0.25%, 0.50% and 1.0% of OLE. Each diet was fed to triplicate groups of fish (mean body weight 51.22 ±â€¯3.04 g) twice a day (at 09:00 and 17:00 h) for 60 days. The dietary supplementation of OLE did not affect growth performance and feed utilization (P > 0.05). Major changes due to graded levels of OLE in the diets were observed in blood biochemical parameters (P < 0.05). TNFα, IL1-ß and IL-8 gene expressions were significanlty up-regulated in OLE 0.1% group compared with others (P < 0.05). Also, diet supplemented with OLE reduced mortality in rainbow trout fed with OLE 0.1% added diet. Present study suggests that OLE especially at 0.1% added feed may effectivelly enhance the serum biochemical parameters, survival rate and immune gene expression in rainbow trout.

Evidence of threat to European economy and biodiversity following the introduction of an alien pathogen on the fungal-animal boundary.

Recent years have seen a global and rapid resurgence of fungal diseases with direct impact on biodiversity and local extinctions of amphibian, coral, or bat populations. Despite similar evidence of population extinction in European fish populations and the associated risk of food aquaculture due to the emerging rosette agent Sphaerothecum destruens, an emerging infectious eukaryotic intracellular pathogen on the fungal-animal boundary, our understanding of current threats remained limited. Long-term monitoring of population decline for the 8-year post-introduction of the fungal pathogen was coupled with seasonal molecular analyses of the 18S rDNA and histological work of native fish species organs. A phylogenetic relationship between the existing EU and US strains using the ribosomal internal transcribed spacer sequences was also carried out. Here, we provide evidence that this emerging parasite has now been introduced via Pseudorasbora parva to sea bass farms, an industry that represents over 400 M€€ annually in a Mediterranean region that is already economically vulnerable. We also provide for the first time evidence linking S. destruens to disease and severe declines in International Union for Conservation of Nature threatened European endemic freshwater fishes (i.e. 80% to 90 % mortalities). Our findings are thus of major economic and conservation importance.