Nifty, John; Dr. Mohamed Hatha, A.A(Cochin University of Science & Technology, April , 2014)
[+]
[-]
Abstract:
The thesis deals with the prevalence and distribution of motile aeromonads in selected ornamental fishes. The presence of motile aeromonads in ornamental fishes and associated carriage water is well documented. Though aeromonads are a part of autochthonous flora of natural waters, disease outbreak occurs as a result of
environmental stress on the cultured species and virulence of the pathogens.
While ornamental aquaculture in many parts of the world is highly organized and
practiced scientifically, it is highly unorganized in India. The culture ponds/tanks
are often maintained in very poor manner and the fishes are subjected to high
degree of stress during transportation from the production facility to retail
vendors. The situation is no better at retail outlets, where fishes are maintained in
crowded condition without proper aeration or food. All these could result in high
prevalence of diseases caused by motile aeromonads. No systematic study has been carried out to understand the prevalence of motile aeromonads in ornamental fishes and carriage water . It also gives an account of the production of extracellular virulence factors and the antibiogram of the different species of motile aeromonads isolated. The growth characteristics and virulence potential of a representative strain of Aeromonas hydrophila is also studied. The nucleotide sequencing of the strain was carried out and sequences deposited in Genbank. Survival and immune response of Cyprinus carpio under different stress conditions and on probiotic treatment with Bacillus NL110, when challenged with A. hydrophila is also dealt within this thesis.