Many people assume that pet fish have short lifespans, but with proper care, some species can live for over a decade—or even several decades. The key to their longevity lies in maintaining a clean, stable environment, offering a nutritious diet, and meeting their specific care needs. Whether you prefer a colorful koi for your pond or an intelligent Oscar for your tank, choosing a long-lived fish means making a lasting commitment. Here are 12 fish that can thrive for 10 years or more.

1. Koi Fish (20–25 Years Or More)

Koi fish are one of the longest-living pet fish species, with an average lifespan of 20 to 25 years. However, under ideal conditions, some koi have lived much longer. The most famous example is Hanako, a koi that reportedly lived for 226 years. These fish originate from the Black, Caspian, and Aral Seas but have been domesticated for centuries, particularly in Japan, where they are cherished for their beauty and symbolism. Koi require large, well-maintained ponds with proper filtration and aeration to thrive. They can grow up to three feet long and weigh over 30 pounds, so space is crucial. 

2. Goldfish (10–25 Years)

Goldfish are one of the most popular pet fish worldwide, often mistaken for short-lived creatures due to improper care. While many goldfish kept in small bowls survive only a few years, they can actually live for 10 to 25 years in the right environment. Some have even been recorded living over 40 years. Goldfish are a type of carp, originally domesticated in China, and they come in various types, including common goldfish, comet-tailed, telescope-eye, and oranda. To ensure their longevity, they need a spacious, well-filtered tank or pond with stable water conditions. 

3. Oscar Fish (10–18 Years)

Oscar fish, part of the cichlid family, are known for their intelligence and personality. These fish can live between 10 and 18 years with the right care, making them a long-term commitment for any fish owner. Originally from the Amazon River, they require a warm freshwater environment with temperatures between 74–81°F. Oscars grow up to 18 inches long, so they need a large tank, at least 75 gallons for a single fish. They are territorial and can be aggressive, especially during breeding, so tank mates should be chosen carefully. 

4. Discus Fish (10–18 Years)

Discus fish are one of the most visually stunning freshwater fish, known for their round, flattened bodies and vibrant colors. Native to the rivers and lakes of South America, particularly the Amazon Basin, these fish require special care but can live up to 18 years when properly maintained. Unlike many other freshwater fish, discus need warm water between 82–86°F and a low-pH environment to stay healthy. They are social and do best in groups, but due to their peaceful nature, they should be housed with non-aggressive tank mates. A tank of at least 75 gallons is ideal for a small group. 

5. Figure 8 Puffer Fish (15+ Years)

The figure 8 puffer fish is a fascinating species known for its intelligence and playful behavior. Unlike many freshwater fish, figure 8 puffers thrive best in brackish water—a mix of freshwater and saltwater. When given the right environment, they can live well beyond 15 years. These fish are small, usually reaching about 3 inches in length, but they require a spacious tank of at least 15–30 gallons per fish. They are semi-aggressive and should be housed alone or with carefully chosen tank mates. One of the most important aspects of their care is their diet. 

6. Clown Loach (15+ Years)

Clown loaches are a favorite among aquarium enthusiasts because of their bright colors and playful nature. Originally from Indonesia, they can live for more than 15 years if properly cared for. These fish have striking orange bodies with black stripes and red fins, making them a visually appealing addition to any freshwater tank. Clown loaches are social fish that prefer to live in groups of five or more. They require a spacious tank—at least 75 gallons—as they can grow up to 12 inches long. A well-maintained aquarium with clean, well-oxygenated water is essential. 

7. Catfish (Up to 15 Years, Depending On Species)

There are thousands of catfish species, but some make excellent long-lived aquarium pets. Popular choices like the red-tailed catfish, armored catfish, and Rafael catfish can live up to 15 years with proper care. These bottom-dwelling fish are known for their distinctive whisker-like barbels and scavenging habits. Catfish require a well-filtered aquarium with plenty of hiding spots, as they are nocturnal and prefer shaded areas. Tank size depends on the species—some grow only a few inches, while others can reach several feet in length.

8. Firemouth Cichlid (10–15 Years)

Firemouth cichlids are a hardy and vibrant freshwater species named for their bright red-orange throats, which they flare out during territorial disputes. Originally from Central America, these fish can live up to 15 years if given proper care. Their manageable size (about 6–7 inches) and relatively simple care requirements make them a great choice for both beginners and experienced fish keepers. Firemouth cichlids require a minimum 30-gallon tank with plenty of swimming space and hiding spots like rocks and driftwood. 

9. Bichir (15–20 Years)

Bichirs are ancient fish with a prehistoric appearance, known for their elongated bodies and armored scales. Native to Africa, these fish are hardy and can live for 15–20 years in captivity when provided with proper care. They are semi-aquatic and have a unique ability to breathe atmospheric air, allowing them to survive in low-oxygen environments. A minimum tank size of 90 gallons is recommended since bichirs can grow between 12–30 inches, depending on the species. They thrive in soft, slightly acidic to neutral water and require a sandy substrate with plenty of hiding spots. 

10. Rainbowfish (10–12 Years)

Rainbowfish are brightly colored, fast-swimming freshwater fish that can live for over a decade with proper care. Native to Australia, New Guinea, and surrounding islands, these fish are popular among aquarists for their shimmering, iridescent scales that change colors under different lighting conditions. Their hues become more vibrant as they mature, making them a stunning addition to any community tank. A minimum of 30 gallons is recommended for a small school of rainbowfish, as they are highly active and need ample swimming space. 

11. Bala Shark (10–15 Years)

Despite their name, Bala sharks are not actual sharks but belong to the cyprinid family. They are active, schooling fish that can grow up to 14 inches in length, requiring a large tank of at least 125 gallons. These fish are peaceful but need to be kept in groups of at least four to six to prevent stress-related health issues. Bala sharks thrive in clean, well-oxygenated water with a moderate current. They are omnivores and should be fed a varied diet of high-quality pellets, frozen foods, and vegetables. 

12. Clown Knifefish (15–20 Years)

The clown knifefish is a distinctive species with an elongated, blade-like body and a unique undulating swimming motion. Native to Southeast Asia, they can grow over 3 feet in length, requiring a massive tank (at least 200 gallons) or even a pond. These fish are nocturnal predators that prefer dim lighting, hiding spots, and a peaceful environment. They primarily eat live foods such as shrimp, small fish, and worms. While they can become tame with their owners, they are best suited for experienced fish keepers due to their large size and specific care requirements. 

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