Dissertation > Agricultural Sciences > Aquaculture, fisheries > Fisheries Protection > A variety of fish diseases, predators,and its control

Correlation between Bacteria Associated with Customary Feed and Diseases Occurrence of Cultured Turbot Scophthalmus Maximus

Author LiuChaoYang
Tutor WangYinGeng;ChenJiXiang
School Ocean University of China
Course Marine biology
Keywords Turbot Ascites disease Small trash Vibrio alginolyticus Pellet feed White feces disorder False Alteromonas spp.
CLC S943
Type Master's thesis
Year 2007
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Turbot since the introduction of China since 1992, with its unique biological characteristics, rapid development to become a pillar industry of China's marine aquaculture, which triggered the fourth wave of mariculture. The end of 2005, the farming area has more than 500 million square meters, more than 700 the number of farming enterprises, output of nearly 500 million tons, the output value of more than seven billion yuan, and has achieved good economic and social benefits. However, the in-depth development of intensive farming of turbot breeding density is too high, the bait, the accumulation of feces, resulting in a large number of pathogenic microorganisms multiply, causing fish onset diseases increasingly become a constraint turbot farming industry healthy, stable and rapid development bottleneck. In order to identify the cause and find out the real source of pathogenic bacteria, our research group in Shandong Province from 2005 to 2007, most of the turbot farms expand bait bacteria survey, one hundred in the investigation of turbot breeding plant use feed, bait used more than 90% of the manufacturers carry a different number of bacteria, especially small trash fish breeding plants, bacteria content 106CFU / g. To identify bait relationship flounder disease carrying bacteria and farmed turbot in the course of that investigation, we had the honor of turbot and bait small trash Yantai, a turbot farms suffering from ascites disease by well water, pond water and a small trash bacterial detection of this farming system, small trash fish carrying the bacteria and the bacteria from diseased fish in vivo morphological consistency through artificial infection test and found that the two bacteria (FS The -1 and RF-1) are pathogens, can make health turbot suffering from ascites disease, its clinical characteristics consistent. Combination of traditional biochemical identification after the identification of API-ID32E 16SrRNA gene sequence analysis the bacteria FS-1 and RF-1 for the same kind of bacteria alginolyticus Vibrio (V.alginolyticus). Using the same method, Laizhou, Penglai and Weihai three factory farming of turbot turbot are different degrees of suffering white feces disease, bacteria and pathogens and the three pellet feed plant breeding carried consistency strict bacteriological identified by the above method, these two bacteria (BB-1 and KL-1) is false Alteromonas genus (Pseudoalteromonas sp) in a certain kind of bacteria. On the basis of this study, these four Zhu Zhu bacterial drug sensitivity test, the test results show that the bacteria in the FS-1 and RF-1 susceptibility spectrum consistent bacterial BB-1 and KL-1 antimicrobial resistance also consistent. Again showed that the small trash fish and feed pellets to carry the bacteria can also lead to the turbot incidence, they are the direct source of infection of turbot flounder disease. However, the analysis from the health point of view, the amount of feed pellets carrying bacteria was significantly lower than the carrying amount of small trash fish bacteria. Meanwhile, animal feed bacteria detection, although not directly confirm Seedling turbot olivaceus incidence of the disease and the animal feed to bring the relationship between the bacteria, but they carry a huge quantity of bacteria, especially rotifers, and the number of bacteria can reach about 1010CFU / g. In Weihai, a turbot hatcheries disease course of the investigation, it was found to the frozen Artemia carry bacteria more than 90% of the Vibrio bacteria, and the advantage of a very high degree. Carry bacteria and Vibrio pathogenicity no in-depth study, however, can be predicted to carry some kind of dominance high bacteria live prey will inevitably lead to the seedling stage turbot incidence. In addition, more than 10 days Laizhou a streak Star flounder hatcheries Seedling emergence suspected ascites disease of the entire nursery bacteria investigation found, to the A, B and C three bacteria isolated from diseased fish from rotifers three bacteria of LH-1 and LH-2 and LH-3 colony morphology, while the other samples did not contain these three bacteria, therefore, it is possible to initially identified pathogens from rotifers, therefore, enhance the health of the animal feed culture. optimize culture methods, the key is located to prevent the the seedling stage turbot disease occurred. In May 2006, the laizhou a Senegal sole (Solea senegalensis) nursery grounds occur more serious strange disease, when black body seedling growth to 10 a few days, soon died, a mortality rate close to 100%. This phenomenon, we have the entire nursery system for bacteriological survey, the survey found that diseased fish carried by the bacteria, numeral SN-1 from the nursery systems use a bacterium isolated in beneficial bacteria in the MIC, reference numeral After the bacterial culture that for M-1, are very similar morphology, these two bacteria Vibrio susceptibility testing on an M-1, and found that this is not an ordinary Vibrio, most antibiotics. not sensitive, and only very few of the presence of antibiotics weak sensitivity, therefore, suspicious is a filtered engineered bacteria. The papers carry the bacteria in their disease correlation study of turbot commonly used bait for turbot healthy breeding and disease prevention and control work to provide a theoretical basis and reference.

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