Fishes for garden ponds
One of the most exciting aspects of the garden pond is the livestock that it can support. Of these, the most spectacular and interesting are the fishes, which provide a continuous movement and sparkle that people of all ages find fascinating. The golden varieties of fish are the most easily seen and appreciated; the dark green varieties are well camouflaged and need patience to see them and watch their movements. The brighter fish are more vulnerable to predators, and a sufficient cover of plant life in the pond is necessary for their protection.
Fishes are important to the pond environment, as they take in oxygen from the water and then expel carbon dioxide through their gills; the carbon dioxide is then absorbed into the plant tissues along with water. Carbon, hydrogen and oxygen are processed within the plant with the sun’s rays, a process called photosynthesis, giving off surplus oxygen into the water for the fishes to take up again and repeat the cycle for the benefit of both fishes and plants. At night the process is reversed, with the plants taking up oxygen and releasing carbon dioxide. This can cause a low level of oxygen in the morning making the fishes sluggish. As soon as the sun rays start working on the plant life the oxygen starts moving again.
Some fishes are scavengers, acting as unwitting cleaners in the pond by taking up debris from the pond floor and water as food. It is advisable to cover all soil with a layer of stones or gravel to prevent the soil being stirred up and clouding the water, stopping the fishes from being seen clearly in the pond.
For describing each individual species of fish, there is a detailed terminology for the various fins and points; this is very useful to know about in order to read the literature supplied by fish fanciers and dealers, and books on the subject.