Freshwater Fish
Assorted Koi.
Young koi in assorted colors — pond fish that grow large and live for decades. Hardy and beginner-friendly, but plan ahead: these belong in a pond or a very large tank as they grow. Great starter stock for a backyard water garden.
We keep this species at our Erie store. Come and see it in the tanks, or call (814) 456-9445 and ask what we have in right now.
Sea Cave keeps this species. You will find these in the tanks at 660 East 14th Street in Erie. We never ship live animals.
- Condition
- new
- Fulfillment
- Local pickup — Erie, PA
We never ship fish, coral, or invertebrates — every animal here is one you meet in person. Each one is acclimated and health-checked in-house before it goes out into the display tanks. This is a species we keep, and what is swimming on any given day changes with the deliveries, so please call (814) 456-9445 before you drive in.
Care at a glance
What to know before you take one home.
- Care level
- Beginner
- Temperament
- Peaceful
- Adult size
- 36"
- Min tank size
- 250–1000 gal by age
- Diet
- Omnivore
- Scientific name
- Cyprinus rubrofuscus
Grows into its tank
Juvenile (under 12 in)250 galAdult (full grown)1000 galGood tank mates
These are young pond fish that grow large and live for decades, so tank pairing isn't really the question here. Compatibility depends on the individual and your setup, so call us for pairing advice before mixing them with anything. As a rule, do not house koi with small fish they can eventually eat.
Good to know
Koi are a colored ornamental form of the Amur carp, bred for color in Japan starting in the 1820s, and can live for several decades.
What is in the tanks and each animal's temperament vary — call (814) 456-9445 for pairing advice.
Good tankmates
Plays well with.
Species we’d keep in the same tank, with why each pairing works. What is in the tanks and each animal’s temperament vary — call (814) 456-9445 for advice on pairing.
New to stocking a tank? Read our guide on which fish live together.
Oranda Goldfish
Classic, well-documented koi companion sharing the same cold-water freshwater range, similar adult size, and peaceful temperament. Both species thrive under identical water parameters and neither exhibits aggression or fin-nipping toward the other.
Oranda Goldfish
Calico single-tail goldfish variety with identical cold-water requirements and a peaceful disposition. Widely documented as compatible with koi in both aquarium and pond settings with no aggression or parameter conflicts.
Oranda Goldfish
Red-and-white single-tail goldfish that is virtually identical in care requirements to Comet Goldfish and Shubunkin. Published care guides explicitly recommend this variety as a koi companion; shares cold-water parameters and a non-aggressive temperament.
- W
Weather Loach
Peaceful cold-water bottom dweller tolerating 50–82 °F, fully overlapping with koi's preferred range. Occupies the substrate level exclusively, eliminating resource competition with mid-water koi, and is not known to nip fins.
Visit the store
660 East 14th Street,
Erie, PA.
Mon–Fri 12–6 · Sat 11–4 · Sun closed. Call ahead on livestock — what's on the floor rotates.