Biology abd life history

Who are the Nechako
Sturgeon?

BIOLOGY AND LIFE HISTORY

The white sturgeon (Acipenser transmontanus) is the largest North American sturgeon species and the largest freshwater fish in Canada.

FISH BITES

Longest sturgeon ever recorded?
6.1 metres*

Heaviest sturgeon ever recorded?
629 kilos*

*It’s hard to know how big the biggest sturgeon ever caught was, because different people say different things. For some of the sturgeon that were caught when Europeans first started fishing for them, we only have written reports or letters about how big they were. Perhaps the largest sturgeon are still out there.

More about the white sturgeon…

Age
Scientists think sturgeon evolved about 260 million years ago. That means they were around before the oldest dinosaurs existed.

Body
Long and rounded in shape.
Head
Large and broad.
Mouth
The sturgeon has no teeth. Instead it has a protrusible mouth. Protrusible means that the sturgeon can stick it’s mouth out (like a short elephant snout) and suck up food like a vacuum cleaner and then pull its mouth back inside when it’s not eating. (see the drawing below)

More about how a sturgeon eats

Snout
Has a long snout with four barbels located between the end of the snout and the mouth. Barbels are a little bit like the whiskers on a cat (or on a catfish). The sturgeon doesn’t have very good eyes, so it uses its barbels to feel its way around. The barbels help the sturgeon smell and taste its food.
Skin
No scales. The skin is rough and feels rubbery. The skin has little hooks called spiracles attached to it. One biologist described the skin of a sturgeon and feeling like “rubber with little bits of broken glass in it.” There are five rows of armoured plates called scutes running down the body from the head to the tail. The scutes and the spiracles help protect the sturgeon from predators.
Colour
Light grey, pale olive or light brown on top. Light grey to white on underside.

Life history
Observations have indicated that sturgeon spawn in May and June, most often in a swift current with a rocky bottom, or near rapids where the river’s flow is fast. The female lays hundreds of thousands of eggs and the eggs are fertilized by the male sturgeon and sink to the bottom. The baby larval sturgeon hatch from the small, sticky black eggs and travel downstream to where the water is calmer until they become fry. They eat and live on the river bottom for many years until they are adults and ready to spawn. This period may be as long as 40 years for Nechako sturgeon; for sturgeon in the Lower Fraser it is about 25 years.
The Nechako white sturgeon are relations of the other white sturgeon living in the Fraser River watershed and the nearby Columbia River.