Abstract
This study presents data on regular health monitoring of fish in the Aquatika – Freshwater Aquarium Karlovac between October 2016 and December 2019. The Aquatika Aquarium houses 85 different freshwater fish species, 31 of which are endemic in Croatia. The study included an evaluation of the results of the aquarium health monitoring programme. It determined the most common fish diseases in the aquarium (at the species and individual levels) and determined whether endemic or non-endemic freshwater fish are more susceptible to diseases and disorders. The regular health monitoring programme revealed different diseases and disorders in endemic and non-endemic fish. During the monitoring, 3104 fish specimens were analysed. The most frequent disease was ichthyophthiriasis which occurred at a similar frequency in endemic and non-endemic fish species. The results proved to be valuable for the evaluation of risks and measures to minimise the risk of the introduction and spread of pathogens in the aquarium. Preventive fish medicine is extremely important for effective aquarium management. A comprehensive health monitoring programme, including quarantine systems, control of feed and environmental parameters, along with regular fish observation, are critical for the early detection of fish diseases.