The prehistoric-looking sturgeon is known primarily as a supplier of caviar. The sturgeon originated in the former Eastern Bloc countries, especially in Russia. There are numerous species of sturgeon. With its primitive appearance, the sturgeon has a fascinating effect. Therefore, it is no coincidence that some pond enthusiasts wonder if they can keep sturgeon in their garden pond. Sturgeons are pretty hardy. If you would like to house sturgeons in your garden pond, you should first familiarize yourself with the requirements of these fish and the conditions for keeping them.
The Sturgeon – A Fish With High Demands
Sturgeons have been around for 250 million years. Even though their physique and appearance make them appear dangerous, and the name may suggest this, they are not troublemakers but rather relatively peaceful fellows. The living fossils can be found in many places in the wild. They live in the higher latitudes of the northern hemisphere and inhabit the seas and the rivers. The European sturgeon has been considered extinct since 1968. In the meantime, however, sturgeon have been reintroduced into the Oder and Elbe rivers.
In sturgeon farms, which also exist in Germany, sturgeon are bred for the production of caviar. They do not always live there under optimal conditions. It would help if you remembered that you could never offer the sturgeons in your garden pond what they find in nature.
These gigantic fish are pretty hardy and can tolerate cold temperatures. They prefer water that is rich in oxygen and cool water. Since they can reach considerable size, they need a lot of space. The swimming movements of the sturgeons appear primal. Sturgeons have no natural enemies in the garden pond, but they have another problem. They cannot swim backward. Algae, roots, a dense growth of water plants, and other obstacles can become dangerous dead ends for the primordial animals, from which they cannot free themselves. Since not enough water is flushed through the gills anymore, the sturgeons have to suffocate.
A Giant With Many Species
The sturgeon can live to be about 100 years old and reaches a size of more than 16 feet (5 meters) in the wild. It can weigh up to 2200 pounds (one ton). The sturgeon is a bony fish, but its skeleton is only partially ossified. There are rigid bone plates on the back of the sturgeon. The sturgeon has a pointed head. The mouth is not at the top but the bottom of the head. It, therefore, feeds at the bottom of the water. During the day, it usually stays on the bottom, while it also comes to the surface at night. It is a persistent swimmer and constantly on the move. This also explains its need for space.
Currently, 26 species of sturgeon are known. They all grow large, but the smaller species only reach a maximum of 2 feet (150 centimeters). Popular species for pond keeping are:
- Sterlet with a length up to 5 feet (150 centimeters) and weight up to 22 pounds (10 kilograms).
- Güldenstadi with a size up to 6.5 feet (2 meters) and a weight up to 176 pounds (80 kilograms)
- Sternhausen with a length up to 5 feet (150 centimeters) and a weight up to 55 pounds (25 kilograms)
- Siberian sturgeon with a length up to 6.5 feet (2 meters) and a weight up to 220 pounds (100 kilograms)
- Waxdick, similar to the Güldenstadi
- Diamond sturgeon as a cross between sterlet and Waxdick
The different species differ not only in size and weight but also in appearance.
It is a misconception that sturgeon adapt in size to pond size. If they do not reach the size they could in the wild, there are not enough growth-promoting substances such as vitamins and minerals, and the excretion of the fish reduces the growth-promoting substances.
Sterlet – Most Suitable for Pond Keeping
Despite their robustness, sturgeons are demanding and therefore only conditionally suitable for pond keeping. The sterlet, the smallest species of sturgeon, is the most ideal for pond keeping. It is a freshwater fish that thrives in rivers and lakes with strong currents. You cannot fully recreate the current and oxygen-rich water even if you use good pond aeration. The slender sterlet can live up to 20 years. Its long, narrow snout is slightly curved upward. The surface of the sterlet is dark brown to gray. The bone plates on its back are dirty white, and the underside of the sterlet is reddish-white to yellowish.
What Are the Requirements of the Sturgeon to the Pond?
Since the sturgeon cannot swim backward, the pond should be round or oval. It should be at least 5 feet (1.50 meters) deep. Since the sterlet is an active swimmer, you should make sure that the deepwater zone is at least twelve times as long as the body length of the adult sturgeon. Thus, the deepwater area should be approximately 66 feet (20 meters) long. The water volume per animal should be at least 35 cubic feet (1,000 liters). However, since you should not keep just one sturgeon alone, a water volume of 700 cubic feet (20,000 liters) is optimal.
Sloping pond walls are recommended so that the sturgeon can also swim to the water surface. Since sturgeons in nature prefer flowing waters with moderate to strong currents, you should not forget a flow pump. The flow pump can simulate flowing water. Since sturgeons prefer clear and oxygen-rich water, you should think about a robust filter system.
The water temperature should not exceed 68 degrees Fahrenheit (20 degrees Celsius). Therefore, in the summer you should pay attention to shade and good ventilation.
Plants in the Garden Pond
The sturgeon’s enemy is filamentous algae, as the sturgeon can get caught in them. Lush growth can also quickly become a deadly trap. You should therefore keep the growth to a minimum and cut back the plants regularly. Thread algae should be removed.
The Pond Bottom
Sturgeon do not like gravel and sand as pond bottom at all. The sturgeon’s snout is sensitive to sharp edges and stones. The bottom of the pond should therefore have a layer of pond soil or clay. The sturgeon likes to dig for food at the bottom of the pond with its snout.
Under optimal conditions, the sturgeon can even become tame. However, if the water parameters change, parasites can settle and cause the sturgeon a lot of trouble.
What you Should Consider When Feeding
The sturgeon feeds on worms, mollusks, and insect larvae, which it sweeps into its mouth with its barbels. It can only feed on the bottom and therefore needs sinking food. Since the sturgeon reaches a considerable size, the food naturally available in the pond is not enough. It would be best if you supplemented the feed.
The special feed should be rich in proteins and fats. It would help if you fed in the evening, as sturgeon are most active then. It would be best if you fed young fish several times a day. The food should not be in the water for more than an hour. Otherwise, it will not be attractive for the sturgeons. It is recommended to always feed at a specific place in the shallow water zone. As a rule of thumb, the daily amount of food should be approximately one percent of body weight.
You should avoid socializing sturgeon with koi if possible, as koi have different requirements and will eat anything they can get. They quickly eat away the food of the gentle giants while the sturgeons come up short.
Sturgeons are only conditionally suitable for pond keeping. Most suitable is the sterlet, the smallest sturgeon species. The sturgeon makes very high demands on the pond, and it needs clear, oxygen-rich water, a good current, and a high water volume. Since he eats at the bottom, you need to give sinking food.