Goldfish are Carassius auratus. The familiar common, comet, Shubunkin, Oranda and telescope forms are varieties, not separate species. Selective breeding has produced differences in body shape, fins and color. Those differences make the right home and companions a practical question, not a choice based on appearance alone.
How to look after fancy goldfish
A useful first comparison
Common, comet and Shubunkin goldfish are streamlined single-tailed forms. Oranda and telescope goldfish are fancy forms with different body or eye features. OATA advises against keeping common goldfish with fancy varieties because faster fish can outcompete slower fish for food. A shared species name does not make every variety a suitable companion.
Bristol Aquarists’ Society: goldfish varieties · How to look after fancy goldfish
Single-tailed varieties
The common goldfish has the familiar streamlined shape. Comets have an elongated tail, while Shubunkins are known for a calico pattern. These are appearance distinctions within goldfish, not different species.
When comparing these forms, start with the adult fish’s swimming room and the complete group you intend to keep. A short shop display is a place to view a fish, not a model for its long-term home.
Bristol Aquarists’ Society: goldfish varieties
Fancy varieties
An Oranda has a head growth often called a wen. Telescope forms have prominent eyes. Other names, including Ryukin, describe further selectively bred forms. This comparison identifies visible differences; it does not provide procedures for cleaning, trimming or treating those features.
Bristol Aquarists’ Society: goldfish varieties
Choose for the adult fish and the work you can maintain
OATA advises against choosing goldfish for small unheated aquariums. Plan housing for the adult fish and variety rather than choosing from the fish’s current shop size.
Before buying, confirm the expected adult size, available swimming room, filtration and intended companions with an experienced aquatic retailer. Discuss any home constraints before committing to the fish.
- Measure the aquarium footprint and note the space left after decor and equipment.
- Record the exact variety or any identification uncertainty.
- Set aside space and a storage plan for maintenance equipment.
- Include equipment replacement and cover during travel in the ownership budget.
OATA: fish for unheated aquariums
Keep water quality on the calendar
Set up and cycle the aquarium before adding fish. Cycling establishes biological filtration so bacteria can process fish waste. Clear water can still contain substances a test kit detects; it does not show that a new aquarium is ready.
Keep a dated test and maintenance log. Record equipment changes and additions to the group, so a caregiver can see what changed rather than working from memory. Choose the maintenance plan for the actual system with knowledgeable support.
RSPCA: creating a good home for fish
The next useful step
Choose the variety with adult space, compatible company and upkeep in mind. Bring the written plan to the seller before purchase, and keep it for the person who will cover your routine while you are away.
Plan your next step
Browse fish guides · Organize pet routines · Use the free Pet Life Checklist · Guppy overview · Molly overview
Sources and further reading
- How to look after fancy goldfish (checked 13 October 2026)
- OATA: fish for unheated aquariums (checked 13 October 2026)
- RSPCA: creating a good home for fish (checked 13 October 2026)
- Bristol Aquarists’ Society: goldfish varieties (checked 13 October 2026)