Mary Allen
Should sturgeons be kept in the garden pond at all and under what circumstances can the keeping be described as “species-appropriate”? We want to deal with these questions and other questions in this entry.
Information on the Sturgeon
The sturgeon is a bony fish, although its skeleton is only half ossified. The shape of the body and the swimming movements make them seem almost primeval, plus the hard bone plates on his back, and it is already believed that sturgeons have existed for around 250 million years. All in all, sturgeons are harmless, peaceful, and robust fish that love cool, oxygen-rich water. The great outdoors disturb many habitats, from rivers to seas – you can find them in many places.
What they all have in common is their ability to swim: They are extremely persistent swimmers and are constantly on the move, which is why they take up a lot of space. During the day they are mostly on the ground, but especially at night they sometimes make detours to the surface.
Other fish are hardly dangerous to sturgeon, it is rather a problem on their part that can cost them their lives: sturgeons cannot swim backward. This is why thread algae, basins with corners, roots, and large stones are a real problem for these fish. Often they cannot break out of these “dead ends” and suffocate because not enough freshwater is flushed through their gills.
There are around 30 sturgeon species worldwide that differ not only in their appearance but also in their body size: The largest species, for example, can grow up to 5 m long and weigh around a ton. A widespread misconception here is that all species can be kept in the pond because their size adapts to the size of the pond. Such a giant sturgeon will hardly limit its growth to 70 cm just because the pond is not big enough.
The sturgeon that is suitable for your own pond is most likely the real sterlet, which is a maximum of 100cm long. It can live up to 20 years, is a pure freshwater fish, and is found mainly in rivers and lakes with high currents. It has a slender, long, slightly curved snout and its upper side is dark brown to gray, the underside reddish-white to yellowish in color. The bone plates on his back are dirty white.
A Pond for the Real Sterlet
As already mentioned, the sterlet is the smallest of the sturgeon family and is, therefore, most suitable for keeping ponds. However, you always have to remember that keeping in a pond never gets to the natural habitat. You can never realistically recreate a river. If you have decided to create the best possible sturgeon pond, the most important thing is to have enough free swimming areas. You should avoid aquatic plants and large stones on the bottom (because of the backwashing issue) and the pond should have a round or oval shape. In such a pond, sturgeons can move their paths undisturbed by obstacles. Another plus point is the sloping pond walls. Here they swim diagonally along the walls and thus reach the surface of the water.
A strong filter system is also important, as sturgeons only really feel comfortable in clear, oxygen-rich water; the joy of swimming can be supported with a flow pump. In general, the pond should be at least 1.5 m deep, but deeper is always better: The at least 20,000 liters of water should be rich in oxygen. If the sturgeon is satisfied and feels comfortable in its environment, it can even become tame.
Feeding the Sturgeon
Another important point here is feeding, as the sturgeon has some peculiarities there. In general, sturgeons feed on insect larvae, worms, and molluscs, which they sweep into their mouths with their barbels. They are therefore only able to eat from the ground. They cannot do anything with floating feed.
Due to their size, the food that is naturally in the pond is not enough; Special feed must be fed. The special thing here is that it sinks to the bottom quickly and does not exceed a carbohydrate content of 14%. The protein and fat content is very high. Feeding should take place in the evening, as the sturgeons are most active here. Young animals absolutely need feeding several times a day.
You also have to make sure that the food does not lie in the water for more than an hour, otherwise, it will be completely ignored. A certain, manageable feeding area should therefore be used, where the feed is not scattered too far and thus “overlooked”: It works best in the flat zone. The guideline for the amount of feed is that around 1% of body weight should be fed per day.
A special case arises when sturgeons are associated with Koi. These fish are known to be omnivores and if you are not careful, there will be no food left for the poor sturgeon on the bottom. This is also bad for the koi because the high-fat food damages them in the long run. You would gain too much. Either you should feed at night or (which is practiced by many pond owners) you feed the feed with the help of a pipe directly to the pond floor, where the sturgeons can eat it immediately.
Closing Word
Ultimately, you have to decide for yourself which position you want to take on the sturgeon issue. However, if you decide on such a fish, you also have to create the necessary pond properties so that the sturgeon can feel comfortable. And that includes above all space, space, space!