Materials and Methods
Animals -clinical history and Sampling
In 2019, during the routine managment activities held by a company specializing in ornamental cichlids trade, some fish showed aspecific signs of disease and were noted. An investigation about possible underlying diseases was conducted.
The fish were kept in 250 L tanks, equipped with independent filters and holed bricks used for shelter by the animals. Two fish samplings conducted in August and October, were carried out. During the first sampling the water temperature was 27°C-28 °C. The second sampling had a consistent temperature of 24 °C. All fish in the first sampling came from breeding activities within the company, whereas the second sampling included a subject that was purchased from another fish farmer and used for breeding.
Mortality outbreaks were not registered in the period before and during the sampling. The selection of the subjects was based on visual and behavioural abnormalities. Thirteen debilitated subjects, which were inclined to be isolated from the group, having nodules and/or dark spots on their skin were chosen. The fish were individually packaged and transported in an insulated container to the laboratory for analyses, then euthanized one at a time with a lethal dose of anaesthetic 2-phenoxyethanol, diluted in the bag used for transport, weighted and measured. Afterwards, sampling was performed with sterile instruments for molecular investigations. Sampling included spleen, liver, kidney, heart, intestine, and any pathological tissue such as cutaneous red or whitish nodules.