The bacterium Edwardsiella ictaluri is considered to be one of the most significant pathogens of farmed catfish in the United States of America and has also caused mortalities in farmed and wild fishes in many other parts of the world. E. ictaluri is not believed to be present in wild fish populations in Australia, although it has previously been detected in imported ornamental fishes held in quarantine facilities. In an attem...

Pancreas disease (PD) is an economically important disease of European farmed Atlantic salmon. It can cause significant losses because of morbidity, mortality and reduced production. The disease is caused by an alphavirus, known as salmon PD virus (SPDV) or salmonid alphavirus subtype 1 in Ireland. To examine whether it is possible to improve the natural resistance of Atlantic salmon to SPDV by selective breeding, 6000 genotyp...

Circular whitish granular lesions, 5–12 mm in diameter, were observed on the skin and fins of a wild northern pike, Esox lucius , caught in a lake in the Republic of Ireland. Histological examination of the lesions revealed hypertrophied cells in the epidermis with deeply basophilic enlarged nuclei and dark‐staining granular material in the cytoplasm. Transmission electron microscopy of these cells revealed naked hexagonal her...