EFFECTS OF TANNIN TREATMENT ON FISH LARVAE'S HATCHING

摘要

Hungary has a strong tradition in pond fish production and in induced fish breeding. The artificial propagation of carp in hatcheries is based on an efficient technology for decades. Though the breeding has an important step which could cause problemsin a lot of cases: the carp has sticky eggs, thus the experts add tannin to each egg lots after insemination and impoundment to avoid stickiness irreversibly. This operates the eggs that they could be hatched in Zug jars. The concentration of tannin islisted as 0,5 mg/1 in references. There is very few knowledge and data about the effects of different concentrations. The application of tannin is also significant in the case of other economically valuable fish species (e.g. catfish, perch) besides carp.