The main sturgeon varieties bred by Royal Belgian Caviar are the Siberian sturgeon, the Russian sturgeon, the Sterlet, the Beluga and the hybrid.
The Siberian sturgeon or Acipenser baeri exclusively lives in fresh water. In the wild it mainly lives in the rivers Ob and Lena in Siberia. It grows just a little bigger than the Russian sturgeon. Weights in excess of 200 kg are exceptional.
The Siberian sturgeon is the most commonly used variety for the production of caviar in European farms.
This variety attains sexual maturity after 5 to 7 years.
The Russian sturgeon or Acipenser gueldenstaedti is praised - together with its close relative Acipenser persicus - for its excellent quality. The Osietra caviar comes from one of these varieties. Like the name suggests, the Russian sturgeon occurs in the wild mainly in the north in the Caspian Sea. The Persian sturgeon is usually captured along the Iranian coast. These imposing, beautiful fish reach a maximum weight of between 100 and 120 kg.
The Russian sturgeon takes a little longer to attain sexual maturity. 7 to 10 years.
The Acipenser ruthenus or the sterlet lives, just like the Siberian sturgeon, in fresh water. With its maximum weight of about 16 kg it is one of the smaller sturgeon varieties.
Despite being smaller in size it produces excellent caviar which can be compared, in terms of egg size, to that of the sevruga. Besides the natural colour the Royal Belgian Caviar of this variety also has a completely white or albino population.
We harvest the sterlet’s unique pearl white eggs after 3 or 4 years.
The beluga or the Huso huso is the king of the sturgeons. Its maximum weight can be over 1,000 kg. It is therefore the largest sturgeon variety. It shares this record with the Kaluga or Huso dauricus. This is in fact the fresh water variety of the Beluga. The Beluga hunts fish. Even smaller mammals like seals are not safe for these giants. This caviar is also very sought after but hardly available. Royal Belgian Caviar has a nice population of this variety. Breeding beluga requires a lot of patience. This variety attains sexual maturity after 14 to 18 years.
As a crossbreed between the Russian sturgeon (Acipenser gueldenstaedti) and the Siberian sturgeon (Acipenser baeri) the Hybrid sturgeon combines the properties of both parents: very good egg quality with a beautiful colour range, but also quick maturation and therefore and more commercially interesting for caviar production. These fish attain sexual maturity after 7 to 8 years.
More about sturgeons
Compared to our modern bony fishes sturgeons are living fossils, as it were. In terms of evolution these fishes have been standing still for the past 250 million years. They still look exactly the same as in the time of dinosaurs.
The skeleton of a sturgeon, apart from the head, is made fully of cartilage. That is why some people wrongly consider the sturgeon to be a cartilaginous fish like rays and sharks.
Sturgeons only become sexually mature at a later age. Depending on the variety this varies between six and fifteen years.
Just like salmon most sturgeons swim from the sea into the river against the flow to spawn. While the salmon dies on the spawning grounds, the sturgeon returns to the sea after spawning. Exceptions are the Siberian sturgeon and the sterlet. These are fresh water fish which never leave the river.
Sturgeons are real carnivores. The plant residues found in their stomach were swallowed when looking for living preys on the bottom and are not its favourite dish. Most varieties feed on snails and worms. Others are strong hunters which mainly hunt for fish. This last part applies to the most legendary and largest sturgeon: the beluga. The sturgeon family has 27 different types.
The history of caviar
Caviar is not a recent invention. The name caviar refers to the Persian word Khag-avar (خاويار), which means strong cake. The Persians believed that caviar improves the endurance and potence.
Even the grandfather of Ginghis Kahn, Bathu Kahn (13th century after Christ) was already interested in this delicacy.
In the Christian Middle Ages caviar was often eaten during the lent in Russian regions as a substitute for meat. Caviar reached its time of glory under the reign of the czars in Russia. The largest consumer of caviar was undoubtedly Czar Nicolas II. Every year he and his court would eat a few thousand kilos of the best sturgeon roe from Astrakhan and Azerbaijan.
Caviar has not always been an exclusive product. At one point farmers would give it to the pigs as feed. In American saloons customers would get free extra salted sturgeon roe with their beer. This is how saloon owners would boost the consumption of alcohol.
For a long time fishermen were the only Westerners who would eat caviar. They had to remove the unwanted eggs before they could sell the sturgeon they caught. Fortunately we now know better and caviar again became a true delicacy.