The
Fish That Lived
with the Dinosaurs
If
you live near the Wolf River, you have more in common
with the dinosaurs that you think. That's because
a special kind of fish lives in the river. If you
visit Shiocton about May 1st, and peer into the
waters of the Wolf River, you will see the same
kind of fish that swam between the legs of a giant
dinosaur as it waded in the water.
Sturgeon
are the only fish that have lived on the earth since
dinosaur times. Most other kinds of fish developed
much later. Long after the dinosaurs had died, the
sturgeon were able to survive. Wisconsin was covered
with glaciers. The sturgeon swam and lived in the
melt water that flowed through the glacier. When
the glaciers completely melted away, the sturgeon
settled in Lake Winnebago, where they still live
today.
Every
spring for thousands of years, the sturgeon have
traveled through the streams, lakes and rivers of
our state to spawn. Spawning is when the female
sturgeon lay eggs and baby sturgeon are born. During
this time, the fish swim in large groups. They are
often so thick that they fill the entire river.
They travel up the Wolf River and people travel
for miles to watch them.
A
sturgeon can live to be very old. The female does
not begin spawning until she is at least 20 years
old. She then spawns only every 4 or 5 years. The
oldest sturgeon found in Lake Winnebago was 82 years
old! A sturgeon's age is measured in the same way
that we measure the age of a tree. If the fin of
a sturgeon is cut open and examined, there are rings
that can be counted.
The
sturgeon also grow to be very large. When they hatch
out of their egg, they are smaller than an inch,
but they grow quickly. When they are 3 years old,
they are already 2 feet (61 cm) long. The average
Lake Winnebago sturgeon is 4 1/2 feet(137 cm) long
and weighs 40 pounds (18 kg). That may be taller
than you!
The
sturgeon is a fish with an amazing history. You
may see one that has lived longer than your grandparents
have. The Sturgeon ancestors have seen many changes
in our land and water.
Source:
Wisconsin Department of Natural Resources display:
"Shadows on the Wolf." at Shiocton, WI, Hwy 54 and
the Wolf River.
