Ornamental Fisheries Fish keeping in captivity is an age-old practice. Chinese used a variety of containers for the purpose such as dishes, bowls and small tanks that permitted viewing from the top. Vivaria were used by Romans to advertise fresh food fishes in restaurants that were kept alive for use or for sale. What is ornamental fish farming? Water management in Ornamental Fish Farming: Ornamental fish production unit requires a higher degree of expertise for greater water quality control as ornamental fish is very sensitive to poor water quality conditions. Many decorative fishes will perish in situations in which more powerful food fish species may survive.