Among tropical fish, they are classified into carnivorous, herbivorous, and omnivorous types due to differences in the water bodies and environmental factors they inhabit. Most tropical fish are carnivorous and prefer animal – based baits. Fish that eat animal – based baits grow and develop rapidly because such baits are rich in nutrients. Some tropical fish species are omnivorous, consuming both animal – based and plant – based baits. There are also some tropical fish species that mainly feed on plant – based baits and occasionally eat some animal – based baits, but this type of tropical fish accounts for only a small proportion.
Animal – based baits refer to planktonic organisms in water, such as small flea – like insects. However, when artificially raising goldfish, ground – up animal livers can be used for feeding, and fish, shrimp, meat, and cooked egg yolk powder are also suitable.
The appetite of tropical fish is closely related to water temperature and dissolved oxygen content in water. If the water temperature is low or the dissolved oxygen in water is insufficient, the activity level of the fish decreases and their appetite is poor. In this case, the feeding frequency should be reduced to once a day. When the water temperature is 20°C and the dissolved oxygen content in water is normal, feeding should also be done only once a day (it is not advisable to feed in the early morning or evening). When the water temperature rises to 22°C – 25°C, the appetite of tropical fish increases, and they should be fed twice a day (the feeding time can be from 8 – 9 am and 3 – 4 pm). During the stages when female fish are carrying eggs, young fish are growing and developing, or when several types of fish are kept together in a mixed – culture setup, the fish will compete for food, and they can be fed 2 – 3 times a day.
For smaller fish such as neon tetra, red rose fish, and goldfish (here, it might be a misnomer as goldfish is not a tropical fish in the strict sense, perhaps referring to some small – sized tropical fish similar to goldfish – like appearance), due to their low activity levels, feeding them once a day at a fixed time is sufficient. If an excessive amount of bait is fed, it is likely to cause the remaining bait to ferment and pollute the water body. For angelfish, blue gourami, kissing fish, etc. that are reserved for spawning, the amount of fish worms should be appropriately increased to meet the needs of the gonadal development of these fish species.