Common Goldfish

Geographical Origin and Habitat: A freshwater species; the enclosure should provide stability, oxygenation, space and shelter consistent with its behaviour without turning one habitat description into a mandatory recipe.

Taxonomy and Morphology: The accepted scientific name is Carassius auratus; the verified classification records genus Carassius, family Cyprinidae, subfamily Cyprininae, order Cypriniformes. Historical names remain searchable as synonyms rather than separate species.

Social Behavior: Common Goldfish is social and should be kept in a group. The minimum reference is 2 individuals; sex, maturity and available space can require a more conservative composition. Observe access to food, resting behaviour, chasing and use of shelter. Isolation, persistent competition or aggression means the number, composition or environment needs to be corrected.

Coloration and Sexual Dimorphism: Colour and shape can vary with age, sex, physiological state and environmental conditions. Identification and sexing require recognized species-level characters; one appearance or photograph is not enough.

Aquarium Setup: Common Goldfish needs an aquarium of at least 150 litres, sized for adult body size and a minimum group of 2 individuals. Filtration, shelter and swimming room must match the species and the actual number kept. Volume alone does not make an enclosure suitable: tank shape and length, usable area, oxygenation and the ability to separate territories must reflect adult behaviour.

Diet and Feeding: The recorded diet is omnivorous. Offer appropriately sized foods varied within that category, and adjust quantity and frequency from actual intake, body condition and leftovers. One food or a fixed schedule is not suitable for every age and situation.

Water Quality: Maintain stable, well-oxygenated water appropriate to a freshwater species; the card's reference values are 10–24 °C, pH 7–8. Verify conditions with reliable tests and size maintenance and filtration to the actual load. Ranges are not automatic thresholds for treatment or rapid chemical correction.

Compatibility and Cohabitation: The cohabitation profile is best kept in a species-focused setup, with a generally peaceful temperament. Keep at least 2 individuals; tankmates, stocking density and decor must allow escape, rest and feeding without excessive competition. Watch interactions especially during feeding, maturity and breeding. Persistent chasing, injury or exclusion from food requires a change in stocking or layout, or separation of the animals.

Aquarium Breeding: The recorded reproductive profile is “oviparity”. Breeding should be attempted only with healthy adults, separation capacity and a plan for eggs or young. Do not treat unverified triggers, sex ratios or hatch times as universal for this species.

Risks and Diseases: Prevent problems through quarantine of new arrivals, stable water, appropriate feeding and daily observation. Similar signs can have different causes, so check parameters, history and diagnosis before medication. Follow the product label and qualified aquatic-veterinary advice; there is no universal reduced dose for a species or family.