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BIOLOGY
AND LIFE HISTORY
The
white sturgeon (Acipenser transmontanus) is the
largest North American sturgeon species and the largest freshwater
fish in Canada.
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FISH
BITES
Longest
sturgeon ever recorded?
6.1 metres*
Heaviest
sturgeon ever recorded?
629 kilos*
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*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...
Large
drawing
| Age |
Scientists think sturgeon
evolved about 260 million years ago. That means they
were around before the oldest dinosaurs existed.
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| Body |
Long and rounded in shape.
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| 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.
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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.
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The
Nechako white sturgeon are relations of the other white sturgeon
living in the Fraser River watershed and the nearby Columbia
River.
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