Introduction: The goal of this study was to assess the influence of vaccination against enteric redmouth disease on oxidative stress biomarkers and antioxidant defence in the muscle tissue of rainbow trout (Oncorhynchus mykiss Walbaum) vaccinated against Yersinia ruckeri in the first and second month after immunisation. Material and Methods: Healthy fish were vaccinated orally with inactivated whole cells of a virulent strain of Y. ruckeri. One and two months after immunisation the muscle samples were collected. Results: No significant difference was noted in lipid peroxidation level in either the first or second month after vaccination, while aldehydic and ketonic derivatives of oxidatively modified proteins (OMB) in the vaccinated group were significantly lower in the second month compared to those in the first month after vaccination (P < 0.05). The content of ketonic derivatives of OMB in muscles in the first month after immunisation was higher compared to untreated control. All these culminated in a depletion of glutathione peroxidase (GPx) activity and low level of total antioxidant capacity (TAC). Conclusion: Correlations between catalase activity and lipid peroxidation and TAC confirmed the pivotal role of catalase in antioxidant defence during immunisation. From a broader perspective, it is suggested that immunisation of fish with Yersinia vaccine is associated with induced free radical formation and oxidative stress. Free radicals would therefore be at least partially responsible for the induction of both humoral and cellular elements of the immunity and increased protective immunity against Y. ruckeri infection.

Introduction: The study examined the concentration of total mercury and correlation coefficients between fish size or FCF (condition factor) and the content of Hg in muscle tissue of six freshwater fish: bream (Abramis brama L.), roach (Rutilus rutilus L.), whitefish (Coregonus lavaretus L.), vendace (Coregonus albula L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.). Material and Methods: The fish were caught from the Lake Pluszne located in the Olsztyn Lake District (Poland). Mercury was analysed by atomic absorption spectrometry using Milestone DMA-80 (with dual-cell). Results: The content of the element in the muscles of the examined fish was as follows: pike (0.197 mg/kg) ≈ perch (0.173 mg/kg) > vendace (0.114 mg/kg) ≈ roach (0.095 mg/kg) and roach ≈ whitefish (0.065 mg/kg), and whitefish ≈ bream (0.042 mg/kg) (p ≤ 0.05). In all cases, the content of mercury correlated positively with the body weight and total length of the fish. Only the correlation coefficients between mercury concentration and weight or length of bream were slightly higher (0.979 and 0.977 respectively, p ≤ 0.001). The length and weight relationship of the fish was also determined. Conclusion: The results showed that the levels of mercury were lower than the maximum acceptable limit established by the Commission Regulation (EC) No 629/2008 of 2 July 2008. Thus, they are safe from consumer health point of view.

The current study described the developmental sequence of the ventriculus of the post-hatching Muscovy ducks of both sexes ranging from 1-60 days old, by using gross-histomorphometic measurements and by using light microscope, scanning electron microscope and transmission electron microscope. The ventriculus was extended from the level of the 4th intercostal space to terminate behind the last rib at variable distances dependent on the age of the duck. The statistical analysis revealed that the length of the ventriculus from that of the stomach was decreased by the advancement of the age, while the weight was increased. At all developmental age-stages, the cuticula gastrica was composed of two layers; vertical rods and horizontal matrix. The vertical rods projected slightly as dentate processes beyond the surface of the mucosa at 30-60dys old. The type of the gizzard gland was different according to the age; it was simple tubular type lining by one type of cells (chief cells) at 1-15 days old, but were compound-branched type lining by two types of cells; chief and basal cells at 30-60 days old. By semithin sections, the secretory basophilic granules within the cells lining of the tubular glands were increased by ageing. Transmission electron microscopy exhibited that the chief cells had numerous large sizes electron dense and electron lucent secretory granules. In conclusion, there are wide variations in the morphometrical analysis and the structure of the ventriculus at the developmental age-stages of the duck.

Three different highly consumed fish species from Al-Ahsa market, Saudi Arabia namely Spangled emporer (Lethriuns nebulosus), Red striped seabream (Pagrus major) and Black seabream (Spondyliosoma cantharus) were evaluated for their muscle contents of heavy metals (e.g., Cd and Pb) and trace elements (e.g., Cu, Zn, Fe and Mn). The possible risks associated with their human consumption were also studied. A total of 60 fresh fish samples comprising of 20 samples from each above mentioned fish were collected, and were subjected for determination of heavy metal and trace element contents by Atomic Absorption Spectrophotometry after Microwave Wet Digestion. The results showed that, accumulation patterns of the heavy metals and trace elements followed the order: Fe > Zn > Cu > Mn > Pb > Cd. There were variations among metal contents in the muscles of the three fish species; S. cantharus accumulated the highest levels of Cu, Zn and Mn, while the highest level of Fe could be detected in the muscles of P. major. The concentration of Cd and Pb remained comparable in the muscles of all three fish species. The calculated maximum daily intake (MDI) values were found as 0.0003, 0.0009, 0.0035, 0.0001, 0.0000, 0.0000 mg/day/person for Cu, Zn, Fe, Mn, Cd and Pb, respectively. Conclusively, the present study indicated that, fish muscles contain relatively less burden of heavy metals and trace elements, and no health problem can be raised from human consumption of the examined commercial fishes at Al-Ahsa market, Saudi Arabia. [J Adv Vet Anim Res 2015; 2(3.000): 271-278]