You have an ornamental pond and dream of putting fish in it. Questions then arise about the choice of species, their number and of course their possible agreement.
Fish in my pond
Subtle shimmering or brightly colored, fish complete the pond with their pleasant presence. The species chosen should be based on several criteria:
Cold resistance
In an outdoor pond, temperatures can sometimes drop to very low levels, so it is important to choose fish that are adapted to this situation. Avoid the original varieties of goldfish, such as the "Comêtes" with their beautiful sail-like fins, the black "Black Moor" with bulging eyes, or the "Tête de Lion". Choose hardy species such as the classic goldfish (Carassius auratus), Koi carp or sturgeon which are very resistant to cold.
The depth of the pond
If it freezes, the fish must be able to find refuge in the depths of a pond to avoid being caught in the ice. In cold regions the pond should be at least 80 cm deep to accommodate fish. Some species need depth throughout the year, such as the ide melanote or the sturgeon.
The agreement
Be careful, you should always ask before introducing a new species in a pond already inhabited. Some fish are very combative, others will have no qualms about eating other fish. So beware!
The volume of the pond
It is important to keep in mind that fish need space to live in harmony. For a small pond, prefer the classic goldfish which will be satisfied with 0.1 m³ per fish. This hardy fish has the ability to adapt its size to the space available. Koi carp will need much more space as three of them will need a volume of 5 m³. The ide melanote which is gregarious and needs other individuals of its species to survive as well as the sturgeon will only be introduced in very large ponds offering a surface of at least 20m² and a good depth.
Availability
The majority of the fishes require only limited care. Clean water and a well-maintained pond with a good ecological balance should be sufficient for their needs. Nevertheless, even if the fish feed on larvae, plants or algae, it will be necessary to distribute some food regularly. In winter, feeding will be much less restrictive or even non-existent except for sturgeon which must be fed all year long with special pellets. It is thus one of the most constraining fish.
