Scientific Name of Goldfish:
Goldfish (Carassius auratus) is an aquarium fish of the Carp family (Cyprinidae). Latin name: Carassius auratus auratus (Linne, 1758). Goldfish is a subspecies of freshwater fish of the crucian genus.
One of the first domesticated and one of the most popular aquarium fish in the world.
The name “goldfish” comes from the first, cultivated from the common silver carp (lat. Carassius auratis) aquarium fish of red-golden color with a metallic sheen – a representative of the Cyprinidae family, which became the ancestor of modern goldfish.
Selected and bred by man as early as the 7th century AD, goldfish are domestic pets and have never been seen in the wild. One of the obsolete names for all domestic and pond “goldfish” was – “golden carp”, derived from the common scientific systematic name, Cyprinidae.
The best of the breeds were very expensive not only as favorite pets, but were also worth their weight in gold. New unusual and rare varieties of goldfish are high in price and at the present time, justifying their name – truly “golden”. Koi are also included in the general group of “goldfish”, as a separate branch in the breeding development of pond-aquarium decorative fish farming.
Goldfish grow mainly up to 30 cm, but when kept in a pond, their size can reach 45 cm and weigh 1.5 kg. The size of the fish depends on the volume of the vessel or reservoir, when the animal is kept, as well as on the abundance of food and water temperature. The body of a goldfish is elongated, resembling the shape of its progenitors – crucian carp (silver and gold). A single caudal fin about ¼ of the body length is rounded and straightened. The dorsal fin is from ¼ to 3/8 of the body height. The first anterior ray of the dorsal fin begins near the top of the back. Anal – single, short and rounded. Pelvic and pectoral fins are paired, straightened and also rounded.
Goldfish have bright red-orange colors. There are red and white varieties. The scales of a goldfish cast a metallic sheen.
Goldens need to be fed once or twice a day in small portions so that everything is eaten in 5-10 minutes or less (if you feed twice a day, halve the portions accordingly). Overfeeding is a very common problem when keeping these fish, it can easily lead to various diseases, primarily related to the gastrointestinal tract.
Goldfish are omnivores. Therefore, the diet for them should be varied. This includes live food (you need to be careful with them, often pathogens of dangerous diseases get into the aquarium along with live food; frozen food is safer in this regard), and plant food, and specialized food for goldfish produced by a number of manufacturers (for example, firms Sera, Tetra).
Dry food (both flakes and, in particular, granules) should preferably be soaked for a few minutes in a saucer of aquarium water before feeding. Otherwise, there is a risk that food particles that swell after eating will provoke an upset of the digestive system.
Frozen food should be thawed to room temperature before feeding and fed immediately after thawing. When feeding juveniles with frozen brine shrimp, it is recommended to soak it in water in order to eliminate the excessive salt concentration.
Appearance and gender differences
The body of a goldfish is elliptical, elongated, with a sharp snout and slightly flattened laterally. The dorsal fin of the fish is long, begins in the middle of the body, the anal fin is short, carried to the tail. The color of the body, as well as the fins of the goldfish, is mostly red-gold, the sides are golden, and the belly is yellowish. There are other varieties of color: red, white, yellow, pale pink, black and blue, fiery red and dark bronze. In reservoirs specially created for it, this fish grows up to 35 cm in length, and in aquariumsit is much smaller – up to 15 cm.
Males practically do not differ from females, with the exception of the spawning period. The male, ready for spawning, has characteristic differences: on the first ray of the pectoral fins there is a “saw” in the form of a series of notches, and a white rash appears on the gill covers, similar to grains of semolina. The female, ready for spawning, has a thick belly full of caviar. If you look at the female from above, you can see the curvature of the body of the fish, caused by the presence of eggs. The resulting curvature often remains after spawning.
All goldfish, regardless of species, can spawn in an aquarium with a capacity of 20 – 30 liters. It is necessary to place sandy soil in it and plant small-leaved plants. For spawning, it is customary to plant one female for two or three two-year-old males.
Before spawning, they should be kept separate for 2-3 weeks. In a spawning aquarium, it is recommended to maintain the temperature at 24 – 26 °C. To stimulate spawning, it is necessary to gradually heat the water until its temperature rises by 5-10 °C. At the same time, males begin to quickly rush and chase females, who lose their eggs, scattering them around the entire perimeter of the aquarium, mainly found on plants. In total, the female spawns about 10,000 eggs. As soon as spawning is over, producers need to be removed from the aquarium.
The initial food for the hatched fry will be “live dust”. They can also be given special foods, which are now commercially available in abundance, designed to feed goldfish fry, for example, Sera Mikron.