When most people think of goldfish, they imagine tiny fish in a bowl. But let those goldfish loose in a large pond and they can grow much larger. You may even mistake them for ornamental koi, which have more similarities to goldfish than you may know.
Goldfish and koi are both members of the minnow family. The species have both been bred for physical characteristics that make them great ornamental fish for a pond. Goldfish are native to Asia, particularly China and Japan. These countries are also where modern koi were developed and bred to have their unique patterns and shapes.
Koi and goldfish are both docile species, so they can live together without problems. They are popular fish for ponds because they can tolerate a wide range of temperatures, oxygen levels and cleanliness. For optimum growth and health, they should live in a temperature range of about 65 to 75 degrees F. However, they are both tough species and can survive in more extreme water temperatures.
Koi and goldfish are both omnivores. They both have a tendency to eat pond plants, worms and algae from their environment. In both types of fish, diet plays a role in how brightly colored they are as adults. Specialty foods to enhance pigment can be very expensive but they produce beautiful ornamental fish.
Colors and Patterns
Although many people picture the common, solid-colored goldfish when they think of the animal, there are also varieties of goldfish that have patterns similar to koi. For example, the Sarassa goldfish is red and white, while the Shubunkin goldfish is black, white and orange. Both of these color patterns are common on the more decorative koi.
Kimberly A. Smith has been a freelance writer for two years. She graduated from the University of California at Davis and the California Culinary Academy, then pursued a career baking wedding cakes. During her time at CCA, she received certification in nutrition and food safety. She currently attends the University of Oregon School of Law.