Rainbow trout (Oncorhynchus mykiss) – The rainbow trout is the most widely farmed species among cold-loving fish. It has few bones and tasty meat, which is why it is highly valued and sought after as a delicacy. Its length reaches up to 25-30 cm and weight – up to 1.5 kg. It prefers clean, cool running water, but it can withstand temperatures up to 30° C and low oxygen content. It reaches its sexual maturity at the age of 3-4 years. It feeds on a variety of insect larvae, insects, worms, and larger species and fish. It is of great economic importance. It is subject to breeding in specialised farms. Compared to the river (Balkan) trout, it absorbs artificial food more easily, grows faster and is less demanding of living conditions. In the village of Bozhenitsa, it is rare to this day, due to pollution with all kinds of waste.