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.