About Lake Sturgeon
- Our 360 Portage head office has young sturgeon on display in the customer payment centre. Visitors can see and learn about the fish first-hand.
- The young fish were hatched in the Grand Rapids Fish Hatchery and will be released back into their home rivers after they turn 1-year-old.
- Another popular place to see Lake Sturgeon during the summer is the Silas Ross Memorial Sturgeon Rearing facility at the Jenpeg Generating Station.
- Sturgeon never stop growing and are the largest freshwater fish in Manitoba. The average size is 0.9 to 1.5 m and 3.5 to 36 kg but they can grow up to 2.5 m and weigh over 140 kg.
- Sturgeon can live for over 150 years. Average life span is 50 to 80 years.
- In the wild, sturgeon seem to enjoy tail walking (standing above the water on their tails and moving backwards), especially in warmer weather. They also jump out of the water and twirl around. If you are up at Seven Sisters on the Winnipeg River in July and August you might see them jumping, twirling, and tail walking, like Manitoba "dolphins"!
- Sturgeon have been observed swimming upside down on their backs. Research suggests this might be to feed on insects on the surface of the water. Given the location of the sturgeon mouth, that is the only way it could feed at the surface.
- In the aquarium, sturgeon like to swim through the filter air bubbles, perhaps cleaning their gills. You may also see sturgeon lying on top of each other in tanks.
- Unlike other fish (such as trout), sturgeon tend to have their own unique personalities and behaviours. These behaviours may be feeding strategies or just playfulness.
- Lake Sturgeon (Acipenser fulvescens) are descendants of a prehistoric fish, and look much the same as fossils from the Upper Cretaceous Period 100 million years ago, when dinosaurs roamed the earth.
- The age of a sturgeon cannot be determined externally. Much like a tree, you can tell how old it is by counting the growth rings on the bones of its pectoral fins.
How they look
- From their prehistoric days, sturgeon have an outer armour of bony plates, a skeleton made of cartilage, and a shark-like tail.
- The 5 rows of bony bumps or 'scutes' you see on these young fish will smooth out as they get older. Scutes have little hooked spurs that make the young sturgeon hard-to-swallow and unappealing, protecting them from predators like walleye and pike.
- Young sturgeon often have black blotches on their sides, back, and snout to help them camouflage with the lake or river bottom. These blotches will lighten or disappear when they are about 60 cm long – too large for most natural predators.
- Adult Lake Sturgeon vary in colour from olive-brown to slate grey with a milky white belly.
How they eat
- Sturgeon are benthic, or bottom-dwelling, fish. They have no teeth. When they find food, they extend their tube-like mouths and quickly suck in. Firmly clamping its prey in its jaw, the sturgeon then sucks in some water to strain out any silt or sand through its gills.
- Sturgeon generally live in deep lakes or river habitats were it is dark and murky. As a result, they may not rely on their vision to spot food or predators.
- In an aquarium, they typically won't swim away scared from visitors. (Other fish, like trout, would swim away.)
- Sturgeon rely on their other senses, including:
- Corkscrew shaped nostrils and heightened sense of smell.
- 4 fleshy whiskers (barbels) hang down in front of their mouths which can 'smell' or taste food in the water.
- Ability to detect electromagnetic fields, which enable them to detect a living organism, such as a clam or crayfish, in the lake bottom.
- Sturgeon eat primarily animals, such as leeches, crayfish, small fish, clams, and a variety of insects. The fish in our aquarium eat frozen blood worms. (In the wild, blood worms would be considered a delicacy!)
How they spawn
- Lake Sturgeon are very slow to mature. They do not reproduce until they are at least 15 years old for males and 25 years old for females.
- When mature, females spawn only once every 4 to 6 years. This means only a small portion of the population spawns each year, making them vulnerable to disturbance from overfishing or habitat loss.
- Sturgeon spawn in late spring when the water temperature approaches 11°C.
- A female will release anywhere from 100,000 to 1,000,000 eggs.
- She will typically swim to a spawning area with fast water with a rocky bottom.
- She is met by a number of males that swim around her, drumming on either side of her, which enables her to release the eggs.
- Milt is released simultaneously and the fertilized eggs become sticky and scattered with the river current, finally sinking to stick on the bottom.
- Sturgeon are a heritage species in Manitoba because they have limited distribution, possess unique life history characteristics, and are socially and historically significant in our province.
- Sturgeon are culturally important to Indigenous peoples who called them the buffalo of the water.
- Traditional uses for sturgeon included:
- eating the meat;
- shaping the bones and cartilage into needles, spearheads and arrowheads;
- making glue and paint from isinglass (a substance found in the swim bladder).
- Settlers considered sturgeon a nuisance species and used them for food, tools, and lamp oil.
- Intense commercial fishing for females and their eggs began in the mid-1800s for caviar.
- The Lake Winnipeg commercial sturgeon fishery peaked in 1900 when over 445 tonnes of sturgeon were harvested. As a result, by 1910 the population had crashed and the fishery was closed.
- Sturgeon are currently protected through limited fishing. Sport fishing is strictly catch-and-release.
- There is no commercial harvest of sturgeon. Only First Nations can harvest sturgeon in Manitoba. Many First Nation communities are part of sturgeon management boards focused on protecting and conserving the remaining sturgeon populations.
For more information on the Lake Sturgeon, visit these websites:
- Saskatchewan River Sturgeon Management Board;
- Nelson River Sturgeon Co-Management Board;
- Manitoba Sustainable Development;
- Government of Canada: Species at Risk Public Registry.