When fish enthusiasts decide to create a pond feature in their yard, the first type of fish they consider is often koi. It’s the most popular of all pond fish and the kind you see in ponds at garden centres and in hotel settings. But other varieties of fish are well-suited for your garden pond, too.
Koi are large ornamental carp originating in Japan. With their beautiful patterns and colours, they are a favourite of pond owners. Koi get their names from the Japanese word for their colour and some may have multiple names: “ai” is “blue” and “orenji” is “orange”. The most popular koi are the metallic koi, known collectively as “go sanke”. They are valued for their metallic lustre and all other koi are distinguished from them as “nonmetallic.” Koi are also named for their various pattern that pertain to the quality and percentage of scale covering. Butterfly koi are a variety characterised by elongated fins and barbels, or tactile whiskers.
Not all goldfish are hardy enough to live outdoors all year. The most common and hardiest is the common goldfish. They are available in red and white, white, and yellow to bright orange. Comet goldfish are a species that is highly desirable because of its large dorsal fin and white and red or white and orange patterns. Shubunkin is a variety of goldfish characterised by a multicoloured body pattern in orange, white, black, green, yellow, etc. They give visual interest to your pond as do koi do but are less expensive. Shubunkin are less conspicuous, however, unless your pond water is very clear.
Sturgeon are a less well-known variety of coldwater fish that will do well in a garden pond. The best type to use is the sterlet, which derives its name from the star-shaped body scutes (bony plate) set into its skin. This species is on the small side and requires well-oxygenated water.
The orange-spotted sunfish thrive in outdoor ponds but must not be introduced into a pond with other sunfish. They are recognisable by the white edging around the ear flap behind each eye. The male has distinctive reddish-orange spots.
Tench are prone to linger at the bottom of the pond so work best in shallow water. There are three main varieties of tench: red, red-and-white and green. They are a low-maintenance fish. Males can be recognised by their large pelvic fin; a mature female can lay hundreds of thousands of eggs in a year's time, so if you cannot tell the sex when you are making your buying decision, buy only one tench.
Orfe have narrow, streamlined bodies and require a lot of swimming room. Purchase a small group of them as they can become nervous when they are alone. Orfe can be seen patrolling the surface of your pond on a summer night when they are hunting for gnats. Orfe varieties are golden orfe, silver orfe, and blue orfe.