In Nigeria there is a scarcity of information on fish diseases. Reports are usually not made, except for a few studies by zoologists on helminth and blood parasites of fish. This article presented a few case studies to reflect the status of fish pathobiology.
Modern databases can be successfully used to develop computer-based identification systems. In a first case study, fish larvae were identified with an average of three easily obtained characters. In a second case study, 17 fish diseases out of 20 were diagnosed directly, using an average of six gross signs of a disease.
In the present paper, the phylogeographies of two monogenean species, Pseudokuhnia minor and Kuhnia scombri, on the same species of host, Scomber japonicus, were studied.
Aeromonas species are potential water/foodborne pathogens, whereas Aeromonas veronii bv. sobria is one of the most virulent species to human and fish. Most current experimental evidence has publicized that suicide plasmid dependent IS1-element untargeted integration into A. veronii bv. sobria ATCC 9071T strain was recently used to generate brown pigment-producing and spontaneous pelleting (BP+SP+) mutant. Current study was conducted to compare virulence of wild-type ATCC 9071T strain and its BP+SP+ mutant with respect to cytotoxicity in HeLa cells and lethality in Nile tilapia.
Muscular injection has become one of the direct methods for transferring foreign DNA into organisms. The technique has been recently introduced in the development of vaccines and gene therapy. Vaccine development, in particular, would be desirable in managing viral diseases in farmed fish. In this study, the technique was performed on seabass (Lates calcarifer) and was found that the foreign gene could be transferred successfully through injection into the muscles.
Goldfish, common carp and Nile tilapia were sampled between September 2002 and May 2003 to investigate lesions induced by viral diseases and ectoparasites. Goldfish exhibited neoplasms, Dermocystidium sp., Ichthyophthirius multifiliis (Ich), Trichodina reticulata, Lernaea cyprinacea and systemic infections. Neoplastic and systemic infections in goldfish were associated with viral infection. Oreochromis niloticus and Cyprinus carpio were mainly infested with several species of Trichodina and monogeneans. The presence of Dermocystidium sp.
Aquaculture has become the fastest growing sector of food production in the world. Despite the encouraging trends, several constraints have a negative impact on the growth of aquaculture. Among those, diseases are the primary limiting factors. Bacterial diseases are responsible for heavy mortality in both wild and cultured fish. Antibiotics are used to control such infection but may result in development and spread of antimicrobial-resistant bacteria and resistance genes and occurrence of antimicrobial residues in fish tissues.
Probiotics are widely used in poultry and swine rearing farms but little has been done to incorporate them into aquaculture. This study aimed to pathologically and immunologically evaluate the efficiency of Bacillus subtilis and/or Lactobacillus acidophilus as a potential probiotic in the culture of Nile tilapia (Oreochromis niloticus).
Earlier findings on epizootic ulcerative syndrome (EUS) and the present observation of the authors on transmission of EUS to snakehead (Channa sp.) without skin damage provide evidence to suggest that the invasive fungus associated with EUS is a primary pathogen.
The sustainable development of aquaculture in Egypt needs the efforts coordinated of different sectors. Disease prevention is the most important aspect for protecting the success in the field of aquaculture. Egyptian farmers, like other farmers in other countries, use different chemicals and antibiotics to treat fish diseases. This approach is dangerous to aquaculture because of the residue in fish body and also for the development of drug resistant bacteria that not only affect fish but also induce harmful effect on humans and may have a deteriorative effect on the environment.