Investigate - Life processes
in a vertebrate
This achievement standard requires you to
investigate how life processes are affected by
environmental factors. In this investigation you
will be experimenting on goldfish (scientific
name Carassius auratus).These are the tasks
you will be carrying out:
Task One
1. You will be carrying out a dissection to observe and record structural features
in goldfish. You will link the purpose of these structures to their role in
respiration.
Task Two
2. You will investigate how changing temperature affects respiration rate in
goldfish.
Fish – facts
Ichthyology is the branch of zoology devoted to the study of fish. Watch the
Brainpop movie – then answer the questions about fish:
1. Fish are largest group of vertebrates on Earth – how many known species of fish
are there?
2. What is a vertebrate?
3. Fish are ectothermic - what does this mean?
4. What do all fish use to get oxygen from the water?
5. What structures assist fish to move through the
water?
Bony fish have:
 Skeletons made from…
 Swim ….
Cartilaginous fish have:
 Skeletons made from…
 Bigger ….
Agnathan fish have:
 Not got…
 Ancient ancestors
Fish – movement
Water is almost a thousand times denser than air – this means that it
contains a thousand times more particles per volume than air does.
This makes it much more difficult to move in (how fast could you run in
water that comes up to your knees?) Despite this, the anatomy of a
fish allows it to move quickly and easily through water. Most fishes swim by pushing
their bodies against the water sideways--first to one side, and then to the other.
How do they do this?
The skull remains stable while the bones in the tail
swing backwards and forwards horizontally – pulled
by muscles that make up 80%
of the weight of the fish.
Fins provide stability, giving a
fish control over its movements by directing thrust, supplying lift
and even acting as brakes.
The streamlined shape of a
fish (and special slime
excreted on their skin)
minimises frictional drag and
allows water to flow smoothly
around its body.
While all fish can swim, some species have evolved other means of locomotion.
Certain species of fish can fly, jump or walk on their fins.
Watch these youtube clips:
Flying fish:
http://www.youtube.com/watch?v=gAjzH0vWSIA
Jumping fish:
http://www.youtube.com/watch?v=qfG4vsJ5_xI
Walking fish:
http://www.youtube.com/watch?v=RaogWgXtVe8
The fish dance:
http://www.youtube.com/watch?v=i9SSOWORzw4
Fish – sensitivity
Like all vertebrates, fish have sense organs that allow
them to sense what is happening in their environment.
The organs enable them to ______, _______,
________, ________, and _________.
Touch and the lateral line
Nerve endings in the skin give fish a well developed
sense of touch. In addition almost all fish have a special
sense organ called the lateral line – a series of fluid
filled canals, which enables them to detect movement and vibration in the surrounding
water.
Draw the lateral line on the fish below:
Hearing
Sound is transmitted as waves through both water and air, but sound travels much
faster through water than through the air.
1. Can you explain why? Because water is denser and therefore contains more
particles to transmit sound wave vibrations
Fish have a good sense of hearing and can hear sounds both within and outside of
the water. Draw ears on the fish above? – Do they look strange?
2. If fish don’t have ears like we do, can you suggest how they might hear?
Fish have internal ears
Smell and Taste
All fish can detect (smell) chemicals in the water and most fish have taste buds.
3. Label the nostrils on the diagram of the fish above
4. Do the nostrils on a fish have anything to do with breathing?
No they breathe with gills
Sight
All fish need to see to find food, shelter, mates, and avoid
predators. Fish vision is as good as human vision; many can
see in colour, and some can see in extremely dim light;
however fish eyes are different to human eyes.
Fish eyes can see to the left and right at the same time

Explain why this is a useful adaptation
This is useful because unlike us, fish don’t have a neck and can’t turn their heads
Fish don’t have eyelids

Explain why they don’t need eyelids
Eyelids are designed to keep eyes moist and shield them from bright sunlight – there
is plenty of moisture and low levels of light underwater
Some fish have developed interesting eye adaptations:
Most fish have
one eye on each
side of their
heads
Flatfish (like flounder)
have asymmetrical eyes
– both are on the same
side of their head
The upper side of the fish body (the side with eyes) is camouflaged, while the lower
side is pale.
 Explain how this adaptation provides a survival advantage for a flounder
Flounder hide on the sand on the ocean floor, having both eyes facing upwards
allows them to see predators coming and watch for smaller fish (prey) approaching.
The eyes of the ‘four eyed fish’ of Central America
are raised above the top of the head and are
divided into two different parts. This allows them to
see below and above the water surface at the
same time.

 Explain how this adaptation might provide a
survival advantage for this species.
It allows them to watch for food (insects) and predators at the same time
Fish - Growth
The largest living bony fish is the ocean sunfish (Mola mola) Sunfish have been
recorded at sizes as large as a length of nearly 3.6 m , a height of 4.5 m from fin to
fin and a weight of about 2,300 kg.
http://www.youtube.com/watch?v=mcRX1_ez-oU
Much larger bony fish existed prehistorically, the largest ever known having been
Leedsichthys, of the Jurassic period. Estimates of the size of this fish range from 9 m
to 30 m, but a maximum size of 16 m seems most realistic.
http://www.youtube.com/watch?v=Dekb94CBcK8Growth
A bit closer to home…. How big will my goldfish grow?
Is it true that goldfish will only grow as big as their tank? ____ NO__
Maximum size is determined by genetics. Goldfish will actually grow
to reach different adult sizes (just like humans) but most don’t reach
their maximum size because they die of other causes and grow very
slowly if kept in a confined environment.
The world’s largest goldfish is:
a) 47cm long
b) 4.7 cm long
Remove this text
box to find the
answer
c) 470 cm long
The world’s smallest fish was discovered in 2006 in the swamps in Sumatra. Is it:
a) 7.9 mm long
b) 7.9 cm long
c) 790 mm long
Remove this
7.9
mm
speech
bubble to
find the answer
Fish - Reproduction
I don’t fully trust my instincts, so
I’ve entered the coordinates of the
spawning grounds on my GPS
system
Most fish reproduce by spawning –
this means that females lay jelly-like
unfertilised eggs into the water.
These eggs are then fertilised by
males that release sperm into the
water on top of the eggs.
 What word is used to describe
male and female sex cells? Gametes
Females usually deposit large numbers of eggs (as many as 4-6 million at a time).
After fertilisation, the fertilised eggs are left to develop and hatch without any
parental care.

What word is used to describe a newly fertilised egg? zygote
Many animals use this ‘reproductive strategy’ (abandoning a very large number of
offspring without providing them with any care)

Suggest a reason why this strategy is quite common and very successful
Because so many eggs are laid and fertilised, at least a few can be guaranteed to
survive to adulthood despite being completely abandoned.
Spawning grounds are the areas where fish spawn, or produce their eggs. Many
species migrate (sometimes great distances), to reach their spawning grounds.
Many of New Zealand’s fish species need to migrate between freshwater and the
sea during their life. Their survival depends on it. Fish like (the introduced) trout and
salmon, native whitebait and elvers (young eels) swim up rivers from the sea.
Culverts and weirs that block their passage prevent spawning.
Watch this youtube clip showing how ‘fish ladders’ can be used to assist the
movement of spawning fish.
http://www.youtube.com/user/rojacks00#p/a/u/1/5N-pxGxRPao
Differences in body structure are often used to identify fish species.
1. Label the fins on the fish diagram below:
2. Add another label – identifying the lateral line
Dorsal fin
Pectoral fin
Anal fin
Pelvic fin
3. Now use the information provided in the key to identify the three species of
whitebait shown below.
Key to the identification of Whitebait
1. Are the dorsal and anal fins out of
line?
 Yes – it’s a Koaro
 No – go to question two
2. Is the anal fin triangular in shape?


Yes – it’s a Inanga
No – it’s a banded kokopu
4. Write the correct name of each species beside each picture.
Fish - Excretion
Living in fresh or salty water creates special survival challenges. The excretory
system of fish has evolved to regulate levels of water and mineral salts in their
bodies.
Marine fish must continually _ _ _ _ _
sea water because water is constantly
_ _ _ _ _ _ _ their bodies. Their kidneys
compensate for this water loss by
producing _ _ _ _ _ amounts of dilute
_____
Freshwater fish do not _ _ _ _ _
water because water is constantly
_ _ _ _ _ _ _ _ their bodies. Their
kidneys produce _ _ _ _ _
amounts of _ _ _ _ _ _ urine to
remove this water from their
bodies.
However some fish have evolved
kidneys that are able to adapt to
gradual changes from salt to
freshwater. These fish live quite
happily in rivers or the sea.

Can you name the species of
man eating shark found quite
commonly in Australian rivers? Bull shark
The movement of water into and out of cells is called osmosis.
1. Cut two small fish shapes out of pieces of potato.
2. Weigh each fish, record the weights with vivid on the outside of two beakers
3. Fill one beaker with water; fill the other with salty water
4. Leave overnight, pat dry then weigh again
– Which fish gained weight? – Which fish lost weight?
Fish - Nutrition
This fascinating
engraving is called
“Big Fish Eat Little
Fish”. It was created
by an artist called
Pieter Bruegel in the
sixteenth century. The
image shows a large
beached fish being
cut open to show that
it is full of many other
smaller fish. Many of
the smaller fish are
shown to have
consumed even
smaller fish. This idea
is repeated over and
over in the print.
1. What word describes a fish that feeds by scavenging or hunting for meat?
2. Other fish feed on plant matter and never eat meat – what are these fish called?
3. There is a third feeding classification – what do these fish
eat and what are they called?
4. The diagram opposite is an inaccurate representation of a
food chain – what is missing?
5. Draw a simple marine food chain in the box below
6. What do the arrows in a food chain mean? “Is eaten by”
Many of the body features associated with life processes can be observed by
carrying out a dissection.
In part two of this assessment you will be carrying out a real fish dissection.
Squeamish?
Carry out the virtual fish dissection at this
website:
http://library.thinkquest.org/05aug/00548/Diss
ectionGame.html
Identify the organs or structures and name
the life processes that they are associated with.
Organ =
Associated with the life process of…………..
Structures =
Associated with the life process
of…………..
Organ =
Associated with the life process of…………..
Organ =
Associated with the life process of…………..
Organ =
Associated with the life
process of…………..
Organ =
Associated with the life process of…………..
Organ =
Associated with the life
process of…………..
Organ =
Associated with the life
process of.................
Fish – Respiration
All animals need oxygen to live because oxygen is required for respiration.
Respiration is a process that occurs inside all body cells. During respiration, oxygen
is used to break down glucose molecules. This releases energy and produces water
and carbon dioxide as waste products.
1. What do the respiratory system and cellular respiration have in common?
a) Oxygen plays a key role in both
b) They were discovered by the same scientist
c) Nothing
2. What are the chemical products of cellular respiration?
a) Water and amino acids
b) Carbon dioxide, nitrogen and urea
c) Carbon dioxide, water and ATP
3. What is ATP?
a) A gaseous waste product of cellular respiration
b) An energy packed molecule that powers living cells
c) Another name for oxygen
4. Cellular respiration occur in...
a) Humans only
b) Plants only
c) Almost all animals and plants
5. How does your body get rid of the carbon dioxide produced by cellular respiration?
a) Through your lungs
b) In your urine
c) In your sweat
6. In which organelles does cellular respiration take place?
a) Nuclei
b) Mitochondria
c) Ribosomes
7. Which produces more energy, aerobic respiration or fermentation?
a) Fermentation
b) Respiration
c) They produce the same amount of energy
8. How do we get the glucose we need to power our cells?
a) Breathing
b) Exercising
c) Eating
9. In fermentation, what do cells use instead of oxygen to break down glucose?
a) Carbon dioxide
b) Water
c) Lactic acid
10. What kind of respiration do yeasts use to produce energy?
a) Aerobic
b) Anaerobic
c) They
Fill in the gaps in the equation below:
In order to survive, fish much extract dissolved
oxygen from the water in which they live.
Extracting oxygen from water is much more
difficult than extracting oxygen from air.
Water contains only 3% as much oxygen as an
equal volume of air. It is also much more viscous
(thick) than air; this makes it much more difficult to
move water into and out of respiratory organs.
What do you think?
1. If there is more oxygen in air than water, why
can’t fish survive out of water?
Their respiratory organs have
adapted to function only in water.
Fish absorb oxygen from the water
through tiny blood vessels on the
surface of their gills. Gills stick
together when not supported by
water and can no longer absorb the
oxygen in the air.
Adaptations for living without water!
http://www.youtube.com/watch?v=ZUsARF-CBcI
Check your understanding:
1. Explain why gills only work for cold blooded animals
Their bodies need less oxygen
to survive
2. Draw arrows to show the
direction of movement of water
through the gills
3. Gills are made up of thin pieces of tissue
– what are these called?
Lamellae
4. Inside these pieces of tissues are:
a) Arteries
b) A network of tiny capilliaries
c) Both of the above
5. What process makes oxygen moves from the water to the tissues ?
Diffusion
6. What process makes carbon dioxide move from the tissues to the water ?
Diffusion
7. The natural tendency of molecules to move from an area of high concentration to
an area of low concentration is called.... Diffusion
8. Add labels to the diagram below
9. Add arrows to show the direction that oxygenated blood flows through a fish’s
circulatory system
10. Lamella have evolved to have a large surface area. The bigger the
surface are the more blood comes into contact with water and the more
oxygen the animal can get.
Fish Respiration – a model
1. Cut out the ‘fish parts’ on the next page
2. Cut the ‘gill hole’ in the fish’s body
3. Glue the gill over this hole in the fish’s body. – Don’t glue the whole thing down –
make a flap
4. Glue the gill cover on top of the gill. – Once again make a flap – don’t glue the
whole thing down
5. Poke a hole under the gill, thread the arrow through to show the direction of the
flow of water
6. Glue the carbon dioxide and oxygen labels in the appropriate place
Fish Breathing
When fish are breathing, they are using
muscles to force water containing dissolved
oxygen into and out of the respiratory system
Adult fish have a pair of gills. Each gill is
covered by a bony lid (called an operculum).
A fish draws in water by opening its mouth
and closing the operculum.
When the fish closes its mouth and opens the
operculum, water is forced out and over the
respiratory surfaces of the gill filaments.
One opening and closing of the operculum =
one breath
Watch the animation at this site
http://intranet.wellingtoncollege.org.u
k/resource.aspx?id=93468&officeint
=on

Label the operculum and the
direction of water flow on the
diagram opposite

Do all fish open and close
their mouths to move water
over their gills?
Watch this youtube clip of a fish
breathing
http://www.youtube.com/watch?v=8PlYS3wMuu8&feature=related

Count - how many ‘breaths’ does it take?
Breathing rate and temperature
Oxygen is an essential reactant in the life process of respiration. If fish are to survive,
they must extract dissolved oxygen from the water in which they live.
The concentration of dissolved oxygen in water varies. So if oxygen levels change,
fish must be able to adapt their behavior to allow them to extract as much oxygen as
they possibly can if they wish to survive.

Salty water contains less dissolved oxygen than fresh water

Shallow water contains less dissolved water than deep water

Water containing lots of aquatic plants will contain more oxygen

Water containing lots of decaying matter will contain less oxygen

Use the table above to write a sentence describing the relationship between
temperature and oxygen solubility.
___________________________________________________________________
___________________________________________________________________
Fish respond to changing levels of oxygen in their blood by changing their breathing
rate. However their response is also determined by their metabolism – because fish
are cold blooded they must adjust their metabolic rate to match their external
environment.
When temperature drops fish metabolism slows and fish begin to breathe slower.
They survive because the amount of dissolved oxygen in water increases with
lowered temperature therefore fewer breaths are necessary to absorb oxygen.
When temperature increases, so does fish metabolism and fish begin to breathe
faster. They survive because the amount of dissolved oxygen in water decreases
with lowered temperature therefore faster breathing allows sufficient necessary
oxygen to be absorbed.
Which life
process does
each cartoon
show?