With the burgeoning of May, Portlanders like ourselves try to spend every possible moment in the sunshine. These precious sun-soaked moments could only be enhanced if our fish could enjoy our backyards with us…but wait, some can! Those who have found the love of certain carps can attest, sitting pondside while their large, colorful fish friends swim gracefully through greenery bestows serenity like nothing else on their viewers. Originally hailing from a large group of carps in Central Europe and Asia, pond fish like Koi and Goldfish were domesticated for both food and separately, for their beauty. With the ability to survive cold temperatures, their fast growth rate, large size, long life spans, and interactive personalities, variants of Cyprinus rubrofuscus and Carassius auratus are highly sought after favorites for pondscapers all over the world.
C. rubrofuscus, or “Koi” were originally bred for color in Japan in the 1800’s. Of the dozens of named Koi varieties, the most common colors are white, red, orange, yellow, blue, and black, and they are often calicos with beautiful different-colored markings. Reaching an average of 20 inches in length, they can survive outdoors all year, so long as ponds are at least 1000 gallons in size, 3-4 feet deep, and equipped with an aeration device to keep ice from freezing over the entire surface. Although later growth is slow, some can approach maximum sizes of over 3 feet! They require smooth gravel substrate, scattered water-worn rocks, well oxygenated waters with pumps or waterfalls, and good mechanical and biological filtration. Koi are also happiest in well planted setups, as plants consume fish wastes and maintain stable water conditions. Popular pond plants include Lizard’s Tail, Hornwort, and floating plants like Duckweed and Water Lettuce. Gregarious by nature, Koi should be kept in large groups for both their happiness, and the beauty of their display. Notorious for interacting with their keepers, Koi can be trained to hand-feed and come to greet their human companions. Quality diets consist of low-protein pellets, fruits, vegetables, shrimp, and spirulina.
One of the most popular breeds of C. auratus, “Sarasa Comets” are a playful and exploratory red and white Goldfish. Reaching at least 12 inches in length, these goldfish require a serious upgrade from the carnival fishbowl, and shouldn’t be kept in aquaria smaller than 50 gallons per fish at full size. Due to their gregarious nature, and ability to survive in cold temperatures, Comets do best in pond settings, and they sure look good in them! Gaining their name “Comet” from their long trail-like tails, they are an elegant alternative to Koi that produce far less waste. Tanks and ponds alike should be set up with small, smooth gravel substrate, and tough-leaved plants that are unpalatable to these voracious plant-eaters like Java Fern and Hornwort. For best coloration, they should be fed varied diets with small invertebrates, fresh veggies, algae, and fruit.