Immune Responses to Vibrio anguillarum in Yellowtail Kingfish, Seriola lalandi, Fed Selenium Supplementation

Effects of dietary selenium (Se) on immune competence of yellowtail kingfish, Seriola lalandi, were investigated. The fish were fed one of the three experimental diets including a control diet without Se supplementation and two diets supplemented with Se from Se-yeast (Selplex®) at 2 and 4mg/kg. After feeding for 6 wk, the fish were challenged by injecting Vibrio anguillarum and observed for 2wk. Dietary Se had no effect on feed intake, feed conversion ratio, and survival over the course of 6-wk feeding; however, it significantly increased weight gain and Se content in muscle. Following the bacterial infection, the immune-stimulating effects of Se were observed in antibody, lysozyme, and bactericidal responses, and there was a corresponding increase in survival and hematocrit by Se. Under infectious condition, antioxidant capacity of fish as measured in term of resistance of red blood cells to peroxidation and glutathione peroxidase activity also increased by supplementation of Se. Liver necrosis and kidneymelano-macrophages were only seen in surviving fish fed the control diet after the challenge. Furthermore, there was evidence of myopathy in fish fed the diet without Se supplementation. This study suggests that Se, supplemented at 2 or 4mg/kg, can improve growth and health of yellowtail kingfish

De papier wereld

254 p.; 24 cm

An artist in java and other islands of Indonesia

xiv, 178 hal. : il. ; 20 c

An artist in the tropics,

"Geertruida van Vladeracken-Poortenaar ... is ... part author, part translator ... of this book."Mode of access: Internet

Efficacy of Aqui-S, Formalin and Praziquantel Against the Monogeneans, \u3ci\u3eBenedenia seriolae\u3c/i\u3e and \u3ci\u3eZeuxapta seriolae\u3c/i\u3e, Infecting Yellowtail Kingfish \u3ci\u3eSeriola lalandi lalandi\u3c/i\u3e in New Zealand

This study assessed the efficacy of bath administrations of Aqui-S, formalin and praziquantel against adults and eggs of Benedenia seriolae and Zeuxapta seriolae, two monogenean ectoparasites of kingfish (Seriola lalandi lalandi). Our results showed that 2.5 ppm praziquantel administered for either 24 or 48 h was the most effective treatment for removing B. seriolae (\u3e99%). However, B. seriolae treated with praziquantel for 24 h deposited viable eggs. Formalin at 250 and 400 ppm for 1 h followed by a 5 min freshwater dip was less effective for removing B. seriolae (ca. 80%), but both treatments inhibited the production of eggs by treated parasites. However, a large proportion of B. seriolae eggs exposed to either formalin treatment remained viable. Praziquantel (2.5 ppm for either 24 or 48 h) and formalin (400 ppm for 1 h+5 min f/w dip) were the most effective treatments for removing Z. seriolae from the gills of kingfish (\u3e99%) but the parasites thus removed continued to deposit viable eggs. Exposure to the anaesthetic Aqui-S did not significantly increase numbers of B. seriolae or Z. seriolae removed from the host above those of the control, but it was ineffective in preventing the production of eggs by treated parasites, and did not reduce egg viability. Eggs of B. seriolae were not prevented from hatching unless exposed to air for a period greater than 3 h, and Z. seriolae eggs were only prevented from hatching if exposed to air for periods greater than 5 h prior to the development of eyespots. These results indicate that both primary and secondary treatments will be required to successfully control B. seriolae and Z. seriolae infections in captive kingfish

Jaw malformation in cultured yellowtail kingfish (Seriola lalandi) larvae

Several jaw malformations are common in cultured finfish larvae. Hatchery-reared yellowtail kingfish (Seriola lalandi) larvae were cleared and stained to examine cartilage and bone structure of the jaw. One malformation, characterised by a lowered hyoid arch, was present in kingfish larvae on days 4 and 8 post-hatching, but not on day 12. A different malformation was present in larvae on day 16, typified by abnormal positioning of the lowerjaw and hyoid arch, and breakage of the Meckel's cartilage. Evidence of jaw malformations as early as day 4 suggests that broodstock nutrition may be a factor in the jaw malformation of kingfish larvae, but other potential causes are environmental factors in culture and larval nutrition

The effect of temperature and pH on the growth and physiological response of juvenile yellowtail kingfish Seriola lalandi in recirculating aquaculture systems

A search for a viable new fish species for culture in recirculating aquaculture systems (RAS) in the Netherlands identified yellowtail kingfish Seriola lalandi as having excellent potential. To assist in determining the most appropriate water quality conditions for this species in RAS, the effect of water temperature (21, 23.5, 25, 26.5 and 29°C) and pH (6.58, 7.16 and 7.85) was tested in two separate experiments. Growth performance, feed conversion, stress-physiological and metabolic parameters were assessed in juvenile yellowtail kingfish grown in pilot-scale RAS. Growth was optimised at a water temperature of 26.5°C, in combination with maximum food intake and optimum food conversion ratio (FCR). Increasing temperature from 21°C to 26.5°C resulted in a 54% increase in the fish's final weight after 30. days. A water pH of 6.58 resulted in mortality and inhibited both growth and FCR due to physiological disruptions to which the fish could not adapt