The Beluga Sturgeon or Huso huso, which translates to “great sturgeon,” is a large fish commonly found in the sea basins between Eastern Europe and Asia.
Despite sharing a name with the better known Beluga Whale, the two aquatic species are unrelated.
These massive fish eat smaller fishes and crustaceans, and if left undisturbed, the Huso huso can live for 100 years or more.
Sadly, they are on the World Wildlife Fund’s critically endangered list, as female Beluga eggs are the coveted Beluga caviar.
Long known as a culinary delicacy, Beluga caviar (roe) has led to poaching and overfishing in the Black and Caspian Seas.
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Massive is an understatement when describing the Huso huso, as they are one of the world’s largest freshwater fish and can grow to more than 3000lbs.
While the aforementioned 3000lb case is a rare one, female adult Belugas, which are larger than their male counterparts, can frequently range from 500 to 2000lbs, depending on their age.
They can be anywhere from eight to ten feet, but larger specimens are becoming rarer with overfishing.
While Beluga Sturgeon’s white belly gives them the Beluga name, their upper body tends to be black, gray, or dark green, and their snouts and muzzle area can be a yellow complexion.
Many describe them as “shark-like” due to their large jagged tails. These tails can propel them at relatively high speeds, but this is not their primary objective since they tend to feed upon much smaller prey.
While they aren’t sharks, their epic size is comparable to large sharks like the Greenland and Great White.
Female Huso huso are 20% larger than their male counterparts, and while both genders can produce meat for human consumption, their overfishing comes primarily from attempts to harvest caviar from females.
The Beluga Sturgeon’s relatively long snout has “whiskers” similar to those of a catfish, which are used to help seek out prey underwater.
Several other fins across the Beluga’s body help propel them and steer through the water.
A Beluga Sturgeon can indeed live for up to 100 years or more, but this is less common lately due to overfishing and poaching.
Younger Belugas tend to be slender and less humpbacked than their elderly counterparts, and their mouth and heads continue to grow into old age.
These fish breed for a surprisingly short amount of their lifespans, with males reaching sexual maturity between ages 13-16 and females maturing between age 16 and their mid-20s.
Like many fish, the female’s eggs are left on a river bed for fertilization by males.
Geography influences where this will take place, and some fish travel 100km or less to spawn while others travel over 1000 kilometers.
This depends on their habitats and has been influenced by human encroachment throughout the Black Sea and Caspian Sea basins.
Dams throughout the region limit how far up varying rivers the Beluga Sturgeon can travel, causing disturbances in traditional spawning routes.
Beluga Sturgeon have been seen throughout Eastern Europe and Western Asia, but the highest concentration of these mammoth fishes can be found in the Caspian Sea.
While generally referred to as freshwater fish, they are technically euryhaline, meaning they can thrive in waters with differing levels of saltiness.
Huso husos tend to occupy the middle depths of their habitats, monitoring these areas for smaller prey like anchovies, flounder, and herring.
Their malleability in comfortable depth is reflected in their spawning since females will leave their eggs on seabeds ranging from 15 to 130 feet underwater.
The Caspian Sea is the biggest inland sea on the planet and connects to a myriad of rivers, including the Volga and Ural.
This is where most of the world’s Beluga Sturgeon live, meaning they have been fished for by people from Iran, Russia, Kazakhstan, and Turkmenistan, among others.
Belugas have made their way to the Black Sea as well and tend to live near sea coasts before moving up various rivers during spawning seasons to drop and fertilize the roe.
Despite their massive size, they are timid around humans and other animals they may encounter. It makes tracking their exact population numbers, age, and geographical locations challenging.
Beluga Sturgeon are not quite the intense carnivores that they could be when compared to similarly-sized sharks, but they are indeed a species that preys upon their smaller aquatic brethren. Belugas eat a horde of smaller fishes, including other sturgeon.
Beluga Sturgeon’s massive size makes them one of the most well-known carnivores.
Their shy nature and tendency to avoid humans means not much research has been done on the feeding habits of young Belugas, but much of the prey older fish gravitate towards would be too large.
The Black Sea and Caspian Sea Beluga Sturgeon diets vary depending on what is available, with an abundance of anchovies in the Black Sea and aquatic snails in the Caspian.
Being truly carnivorous, Huso huso will eat pretty much anything that fits in their mouths. This being said, they don’t “bottom feed” or scrape seabeds for algae and plants like other fish species do.
While generally not considered a great fish to keep in a pond or aquarium, aquatic enthusiasts and those with room to house these mammoth animals need to understand their feeding needs.
Beluga Sturgeon require a minimum of 40% of their diets to come from protein and have massive appetites.
They require slightly less food in the winter but still need ample protein and healthy fats to maintain energy.
Beluga Sturgeon’s massive size and “plated” skin makes them largely immune to threats from other animals. Unfortunately, humans pose a significant threat through both fishing and habitat alterations.
Caviar from the roe of the female Beluga is incredibly valuable, making poaching a lucrative endeavor for many living near the seas and rivers in which Huso huso inhabit.
As recently as the 1980s and 90s, there was a healthy population of Beluga Sturgeon, but numbers now remain dangerously low.
A second human threat to the Huso huso is hydroelectric dams and power infrastructure that block off sections of Eurasian rivers.
These rivers are paramount to the fish’s ability to spawn, and blockages have a devastating effect on the species.
Beluga Sturgeon can happily thrive in a wide range of temperatures, so they are largely unaffected by climate change when at home in the Caspian or Black Seas.
Spawning is a different story, with a smaller temperature range being ideal. This is not insignificant but is a lesser threat than that of direct human interference.
Beluga Sturgeon have no known predators once they reach maturity, but adolescents have been known to be consumed by larger fish.
This is a very small concern, however, because they grow very quickly and have a thicker skin that is more challenging to bite through.
Humans are by far the most significant threat to the Huso huso, and without serious conservation efforts, it may soon be too late.
Male and female sturgeon are nearly impossible to distinguish between, so a large number of males get poached in the hunt for female roe.
Because of the reasons we just discussed, Beluga Sturgeon are considered critically endangered.
Since illegal poaching is unlikely to stop anytime soon, people have made proposals to spawn and release millions of fish into the Volga River each year.
Unfortunately, just as bans on poaching have been ineffective, these breeding quotas are rarely met either.
- In 2005, the United States made Beluga caviar illegal to cut down on demand, but it is currently legal to buy again, albeit at exorbitant prices.
- This unique species is one of the oldest fish in existence, dating back at least 200 million years.
- Huso huso are among the largest fish on the planet, along with various species of shark and sunfish.
- The Russian word belyj is what gives this Sturgeon the name beluga for its white underbelly. This name is shared with the unrelated but also white Beluga Whale.
- Ancient Greek, Roman, and Chinese literature notes the harvesting of beluga caviar dating as far back as 1000 BC.