Carassius auratus
Goldfish
A well-kept goldfish is a long-lived, large and interactive pet, which is exactly why the traditional bowl fails them so badly.
CyprinidaeLifespan 10–25 yearsCare complexity 3/5Suitable for beginners
At a glance
- Scientific name
- Carassius auratus
- Family
- Cyprinidae
- Origin
- Domesticated in China over a thousand years ago from wild carp
- Lifespan
- 10–25 years
- Adult size
- 15–35 cm depending on variety
- Weight
- Up to 500 g
- Temperament
- Peaceful, sociable and food-motivated
- Activity level
- Moderate; constant grazing behaviour
- Social needs
- Keep at least two
- Intelligence
- Learns feeding routines and simple trained behaviours
- Noise
- Silent
Housing and environment
- Housing
- Minimum 75 litres for the first fancy goldfish and 40 litres per additional fish; single-tails need ponds or very large tanks
- Space requirement
- Strong filtration is essential — goldfish are heavy waste producers
- Temperature
- 18–23°C for fancy varieties; single-tails tolerate cooler water
- Humidity
- Not applicable
- Exercise
- Long swimming space; single-tail varieties need substantial length
- Grooming
- Not applicable; weekly partial water changes are the core care task
Diet and feeding
Sinking goldfish pellets plus blanched vegetables and occasional frozen foods
Behaviour and compatibility
Digging in substrate, grazing and following people at the glass
- With children
- Excellent family fish with adult-managed maintenance
- With other animals
- Keep with other goldfish rather than tropical species
- Training difficulty
- Low
Health
- Swim bladder disorder in fancy varieties
- Ich (white spot)
- Ammonia burn from poor filtration
- Fin rot
- Dropsy
Test water before assuming disease; ammonia and nitrite should read zero
Special care requirements
Goldfish bowls are unsuitable — they cannot hold stable, oxygenated, filtered water
Before you take one on
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