Today we're going to look at one fish that
really might be two different fish.
Scientifically, it has one name,
but the common names are different.
A steelhead trout and a rainbow trout.
Now these are identical fish
in every way, except for two:
(1) They look a little different on the outside.
(2) And one of them lives
its whole life in freshwater,
while the other one goes to the ocean.
Now, today we're going to look at whether
these really are the same fish regardless,
or whether they are two different species.
My name is Ethan Rotman
I coordinate the Classroom Aquarium
Education Program for the
California Department of Fish and Wildlife
in the San Francisco Bay Area.
We're going to start off today looking
at our fish tank that has baby steelhead trout.
They were put in as eggs four weeks ago,
and we'll see what's happened
in the last four weeks.
We're going to meet a real life scientist,
from UC Santa Cruz, who's going to look
at the two different lifestyles of these fish.
We're going to meet a Park Ranger
from Sonoma County Parks,
who's going to share with us some
footage of real, live, adult steelhead trout.
And we're going to go meet with
our friends Shelly and Derek.
Derek is also a Biologist,
and he's going to answer some questions that
have been sent in by students just like you.
Let's start our journey.
Let's meet with Tom Greer.
He's an engineer, he's an avid fly fisher,
he's an inventor, and he's the one
taking care of our fish.
Are you ready, Tom?
I'm ready for you, Ethan.
And thanks for the introduction.
Welcome to Tank Time with Tom everyone!
Well, it's been four weeks since we
put steelhead eggs into the tank.
Can you believe it?
Well, a lot
has happened since then.
And last week as you saw,
we were looking in the tank and
there wasn't a whole lot to see
because the alevin were hiding.
They were all hiding behind the rocks.
So we're going to go and view
from the top and take a closer look
at what was going on.
Here we're looking at the top of the tank.
And last week remember there were just
a few alevin huddled in the corner?
Well they're all starting to swim up now!
And this is really cool!
I can see a lot of them right now.
They're pretty much fry right now.
The belly sacs are almost gone.
That's amazing!
They're all just hanging out.
I wanted to show you the feeding process.
Now I've just got a little bit of
food on here on a popsicle stick,
so there's not much,
it's like half the size of a pea.
But I'm going to drop a little
bit out in here and that might
get them riled up a little bit.
This is a great view.
But look at them, aren't they just amazing?
I'm just going to hold it right there,
because that's just an awesome view.
They're just so, so amazing to watch.
I sit here for a long time
and just watch them anyways,
because they're just fascinating to watch.
Now, you know, we were
looking at steelhead at this point,
and there's also rainbow trout,
which we're going to talk about.
There's really not a whole lot
of difference between the two.
When you look at them here, OK?
I couldn't tell the difference,
but there are some differences and I
will pass this along to a specialist
that will tell you a little bit,
a little bit more about that. OK?
So we're going to head over to Laura
at American Fisheries [Society]
And she's gonna show us
some similarities and differences
between steelhead and rainbow trout.
So have fun! And I will see
you next week. Here's Laura.
Hi everyone. My name is Laura Goetz
I'm a graduate student at
UC Santa Cruz and a NOAA Affiliate.
I currently study steelhead and rainbow
trout and why some fish become steelhead
and some become rainbow trout.
Let's talk about the similarities
and differences between
steelhead and rainbow trout.
I find it most helpful to look at
species Oncorhynchus mykiss from the
perspective of their life history cycle,
because you can truly appreciate
how rainbow trout and steelhead,
though they look and act very differently,
are actually different ecotypes
of the same species of fish.
Here we have the life cycle
of O. mykiss and you can see
that the hatchling has two choices:
steelhead or rainbow trout.
Let's start at the egg phase and work
our way around the cycle to learn more.
Does anyone recognize these these?
These here are eyed trout eggs from
Trout in the Classroom last year.
These guys don't know it yet,
but they're destined to become rainbow trout.
Now look at these hatchery eggs.
These fish will become hatchery
steelhead when they grow up.
These eggs look pretty similar to me.
We just saw that rainbow trout and
steelhead have the same beginnings.
And now arriving at the hatchling phase.
This is a video of Trout in the Classroom
trout being released into Lake Lomond.
Aren't you lowkey
super proud of them? These fish
have no access to the ocean.
So they will for sure be rainbow trout.
But steelhead start off just like this too.
Whether hatchling will become a rainbow trout
or steelhead depends on lots of things:
like if the hatchling can actually migrate
or not, water temperature
and also genetics.
Juvenile steelhead look identical
to rainbow trout until they undergo
a process called smoltification
that allows them to migrate to the
ocean and survive in saltwater.
Freshwater fish can't live in the ocean.
This also includes rainbow trout.
Can anyone find the rainbow trout
in this group of O. mykiss?
If you guessed this guy, you are correct!
It's pretty wild how different they can look.
Rainbow trout have multitudes
of colors, spots and dots
while steelhead are very silvery.
These differences in appearance come
from their abilities to survive
in different habitats.
Juveniles start to look different
around a year or so after hatching.
Steelhead will migrate to the ocean
but they will still return to freshwater
to spawn with their fellow
O. mykiss steelhead and rainbow trout.
Next up will be journeying over to
Sonoma County Regional Parks to meet Katja
and the adult steelhead living at
the Environmental Discovery Center.
Hi! We are talking about steelhead
and rainbow trout today and I want
to introduce a word right here on
the whiteboard called anadromy
Can you say that?
Fish who travel from their homelands
in a creek or lake to the ocean,
come back to spawn or lay their eggs.
Steelhead are fish who travel!
And they travel out to the ocean.
But the amazing thing
about them is they adapt.
From freshwater, which is their home creek,
to salt water, which is the ocean.
And they will hang out in the estuary,
which is part freshwater part saltwater.
Become adapted to the ocean.
Swim out to the ocean and get
bigger and fatter and eat.
And then an amazing thing is they
will know when it's the time for them
to go spawn in their home creek.
They will find their home creek swim
up it and they will lay their eggs.
Which is called, to spawn.
So these are steelhead.
So do you all have any questions
about rainbow trout and steelhead?
Scientists do, and they have been
studying these fish for years.
Trying to figure out why some
trout travel and some don't.
Wow. Thanks, Katja and Thorston!
That was so great.
It's time for Ask a Biologist.
I'm Shelly Spriggs with Sonoma Water
And I will be asking your questions
to Fisheries Biologist, Derek Acomb
from the California Department
of Fish and Wildlife.
Our first question for Derek comes
from Miles at Arroyo Seco Elementary.
Miles asks: "Why do Steelhead
lay their eggs where they are born?"
Hi Miles! Returning to the same
stream where they are born gives
steelhead a competitive advantage.
And if growing up in your local creek
worked for you, chances are it will
work out well for your offspring!
Fish spawning in the ocean
broadcast many eggs,
the ocean offers little to no
protection and has many predators.
This method of reproducing is easy
to do and has a low investment
in energy from the parents.
While fish spawning in streams
generally have fewer predators,
the habitat protects the eggs and juveniles.
It's really hard to get there
and it requires a huge investment
in energy from the parents.
All this results in better survival
for steelhead spawning
in the streams they were born in.
Thanks for that great explanation, Derek.
Our last question today is from Paige
at Jefferson Elementary. Paige asks:
"Why are steelhead called steelhead?"
Hi, Paige. Go Cloverdale Eagles!
Common names sometimes have
difficult to trace origins.
They can mean many things,
and sometimes they are not unique.
Scientific names are specific
to only one organism and they follow
a hierarchical structure.
Steelhead, after they have gone
to the ocean, have a metallic-like color.
If you use your imagination,
it may look like shiny steel to you.
We may understand what a steelhead is,
but on its own the name isn't very specific
Oncorhynchus mykiss is the scientific name
for rainbow trout and steelhead.
The genus name Oncorhynchus
is a mixture of Greek,
Russian and other languages.
It means "hooked jaw."
When they are ready to spawn,
male steelhead develop
a distinctive curve and hook
in their lower jaw, called a kype.
The species name mykiss
is fashioned after the Russian
name for rainbow trout found on the
Kamchatka Peninsula in eastern Siberia.
I hope by now you can see why there's so
much confusion over whether a steelhead
and a rainbow are the same type of fish,
or whether they're different.
After all, genetically they're the same.
The differences are and how they
look and the lifestyle they choose.
Kind of like people.
Some of us look different
or live differently.
But are we the same...
or are we really different?
That's a question you can answer,
and maybe it's a good thing for
you to create a short video
and send it to your teacher,
or write a poem or an essay and
see what your teacher has to say.
I'm Ethan Rotman
and the California Department
of Fish and Wildlife we'll look
forward to seeing you next time.