Sharks
Sharks are feared by most, loved by some and hunted to death by many, yet they are one of the most magnificent
less understood animals found in our waters all around the world.
Although sharks are fish, they do not have any bones; their skeletons are made of cartilage (a tough fibrous
substance, which is not as hard as bone). Their skin is covered with small, tooth-like structures called denticles and
they do not have scales like other fish.
These amazing animals have been roaming our waters since the age of dinosaurs.
What do they look like?
Sharks are perfectly built for life in the sea. Many sharks
have a torpedo-shaped, stream-lined body and they use
their high tailfin and pectoral fins for steering and balancing.
They can cruise through the water gently, or they can swim
very fast to catch their prey.
How do they breathe?
Like other fish, sharks use gills for breathing. Most sharks swim around with their mouths open, so water flows in
through the mouth, passes over the gills and out through the 5 to 7 gill slits on each side of the head.
What do they eat?
•
•
•
Some sharks, like the great white and tiger sharks, are active hunters (predators); they feed on fish, squid,
seals, penguins or other small sharks.
Other sharks, like zebra and angel sharks, are slow swimmers; they feed on shellfish on the ocean floor.
Whale sharks are filter feeders; they sieve tiny animals (plankton) from the water as they swim.
How do sharks find their food (prey)?
Sharks use their senses to locate prey. Their senses include:
• hearing
o
Sharks can hear very well. They have a small opening on each side of their head which leads to the inner ear.
• smell
o
Sharks can smell very well. Some can detect blood in concentrations as little as one part per million.
• sight
o
Sharks’ eyes are adapted for underwater vision, and many have excellent vision.
• lateral line
o
Sharks and bony fish have a line running on each side of the body called the lateral line. This lateral line detects vibrations in the water, for example, from the movement of other fish swimming past.
• electro-receptivity
o
All living things give off small amounts of electricity just by moving. Sharks have very advanced electro-receptivity and are able to sense these electrical signals to find their food, such as stingrays, hiding under the sand or any prey when the water is murky.
How do sharks eat?
Some sharks swallow their prey whole, others crush their food, but the sharks we are all familiar with are those with
big, sharp teeth for tearing chunks from their prey! Sharks have many rows of teeth, and they never stop growing
new teeth. So, as the front teeth wear out or break off, new teeth take their place.
How do they breed?
All sharks have internal fertilization. Some sharks lay eggs. These eggs are protected by leathery egg cases
and tied to sea weed. The embryo develops inside the egg case and feeds on egg yolk (oviparous). When fully
developed the shark baby, or “pup”’ breaks out of the egg case and looks like the adult.
In other sharks, the embryos develop in the eggs inside the female and are fed from egg yolk (ovoviviparous).
When fully developed they hatch inside the mother and the pups are born alive, looking like the adults. In some
sharks the pups develop in the uterus of the female, getting extra nutrients from the mother, before being born
(viviparous).
Shark parents do not take care of their young. From the moment they are born, the young pups are already able
to look after themselves and hunt for their own food.
Why must we protect sharks?
Sharks form part of the complex food webs in the marine environment and are top predators in the food chain.
Although sharks bite people, human beings are not really their food. Reasons why sharks attack people include:
• Defence – when sharks feel threatened, their only means of defence is to bite.
• Mistaken identification – sharks are thought to confuse humans on surf boards with seals or turtles.
Each year there are 50-70 confirmed shark attacks and 5-15 deaths from shark attacks around the world. Humans
are far more dangerous to sharks than the other way round, and many species of shark are endangered!
Activity
Shark Maths
Solve the maths problem and then substitute a letter for each solution from the letter code to find the name of
your shark.
1 – A
2 – E
3 – G
4 – H
Maths
problem
5–I
6–R
7–T
8–W
7 - (2x2) 2 + (2x2)
√4
1 + (3x0) ½ of 14
Maths
solution
Letter
substitution
My shark is ………………………………………………………………
23
22
¼ of 20 (2x0) + 7 (8÷2) - 2
Dolphins
Dolphins are marine mammals. Unlike fish, dolphins use lungs to breathe and
Dolphins
cannot breathe
under water and need to come to the surface to breathe.
Dolphins and whales are known as cetaceans.
Dolphins are marine mammals. Unlike fish, dolphins use lungs to breathe and not gills, so they cannot breathe
under water and need to come to the surface
to breathe.
What do
they look like?
Dolphins and whales are known as cetaceans.
What do they look like?
Dolphins bodies are torpedo-shaped, their forelimbs are paddles and
they do not have hind limbs. They swim by moving their tail flukes up
and down. Their bodies are covered by a smooth skin with no hair
like other mammals. Dolphins have a thick layer of fat (blubber) under
their skin to keep their bodies warm.
How do they breathe?
Dolphins bodies are torpedo-shaped, their forelimbs are paddles and they do
Dolphins breathe through a hole calledThey
a blowhole
on moving
top of their
head.
water
they close
blowhole
swim by
their
tailWhen
flukesunder
up and
down.
Theirthe
bodies
are covered b
so that water does not go into their lungs. On reaching the surface they open the blowhole breathe out and then
with no hair like other mammals. Dolphins have a thick layer of fat (blubber) u
take a breath to fill their lungs with air. They close the blowhole before diving under water again.
keep their bodies warm.
What do they eat?
How do they breathe?
Dolphins feed on small fish and squid.Dolphins
They havebreathe
beak-likethrough
snouts with
sharp
conical
teeth. Dolphins
chew
a hole
called
a blowhole
on topcannot
of their
head. When
their food; they use their teeth to bite and grab their prey which is swallowed whole.
close the blowhole so that water does not go into their lungs. On reaching the
When hunting, dolphins work together in large schools. They navigate using ultrasound (like bats), making highthe blowhole breathe out and then take a breath to fill their lungs with air. The
pitched sounds that bounce off objects ahead, allowing them to identify obstacles and food while they are moving
before diving under water again.
very fast. Dolphins have a high level of intelligence. They also make a wide variety of sounds and they seem to
communicate with each other. Dolphins are able to hear six times the sound range of the human ear.
What do they eat?
How do they breed?
Dolphins feed on small fish and squid. They have beak-like snouts with sharp
Dolphins
cannot
chew
food;
bite and tail
grab their pre
Dolphins do not lay eggs, they give birth
to live young.
One
calf their
is born
at a hey
time.use
The their
calf isteeth
born to
underwater,
whole.
first. Immediately after birth the calf is helped by the mother to the surface to breathe. Dolphin babies can swim
hunting,
dolphins
work together in large schools. They navigate using u
from the moment they are born. They When
suckle milk
from their
mothers.
making high-pitched sounds that bounce off objects ahead, allowing them to i
Why must we protect dolphins? and food while they are moving very fast. Dolphins have a high level of intellig
make a wide variety of sounds and they seem to communicate with each othe
tofood
hearchains.
six times the sound range of the human ear.
Dolphins are predators at the top of the
Dolphins are often caught in shark nets, so other methods of keeping sharks away are being investigated. Many
do they
breed?
countries, like Japan, harvest dolphinsHow
for food.
At one
time, hundreds of thousands of dolphins were caught
during netting for tuna fish off America, but these nets have been changed to allow dolphins to escape.
Dolphins
do not lay eggs, they give birth to live young. One calf is born at a tim
South Africa has strict laws protecting
cetaceans.
underwater, tail first. Immediately after birth the calf is helped by the mother to
breathe. Dolphin babies can swim from the moment they are born. They suckl
mothers.
Why must we protect dolphins?
Fun activity
Name:
Date:
Dolphin Word Search
Find the related words.
P C Y R W U F N F D J W G E L Z
Z E D C
I
J
A B L Z O C W P D N
U C C V A E X
I
T M O L A X T S
P A B T C R V B
I
L A O P
L
T O
R B E A O L N X C C E S V H F O
Y Y T V S R D I
R E K C Y
C M I
J
R Y A X W D I
A E V Z P X
J
C
E S N
C Q P K L R O S H K B X U
V F M H G L
I O F M R U Q O M S
D T L X
I
Y Q A
P U P W G F
J
D C M F
T W H V L
L O C E U A
I
Z U R Z
I
F X V O G W V P O S W V
Z H M F G I O L V Q A C P K L G
V K A E A V N B Q O X M J
E Q M E D O R S A L
F
I
E P D
N S R X
E M F D P H X C X C K Z G C O S
Carnivorous
Dorsal fin
Mammal
Dolphin
Fluke
Cetacean
Pectoral flippers
Blowhole
Calf
©About.com Homeschooling
http://homeschooling.about.com
need to come to the surface to breathe. On land, penguins use their tails
balance while they are upright.
What do they look like?
The only penguin which occurs naturally on the African continent is the A
Penguins
known
as the Jackass Penguin because of its donkey-like bray. Adults h
head with a black chest stripe. The largest penguin is the Emperor Peng
tall and
weighs
kg or more.
The search
smallest
is the
Penguins are flightless sea birds, and they use their
wings
to “fly”35
underwater
as they
forpenguin
food. They
are Little Blue Pe
Fairy
Penguin),
which stands
40 cm
tall and
weighs
warm blooded (endothermic) and their bodies are
covered
with feathers
to keep around
their bodies
warm,
but they
lack1 kg.
quill (flight) feathers. They cannot breathe under water, so they need to come to the surface to breathe. On land,
penguins use their tails and wings to keep their balance while they are upright.
What do they look like?
The only penguin which occurs naturally on the African continent is the African
Penguin, also known as the Jackass Penguin because of its donkey-like bray. Adults
have a black back and head with a black chest stripe. The largest penguin is the
Emperor Penguin which is just over 1m tall and weighs 35 kg or more. The smallest
penguin is the Little Blue Penguin (also known as the Fairy Penguin), which stands
around 40 cm tall and weighs 1 kg.
What do they eat?
do they
Penguins have a sharp beak with a hook on the What
end, perfect
for eat?
grabbing and holding on to their prey. They have
spines in their throats which point downwards and this stops prey escaping from their mouths while they are
Penguins
sharp
beakand
withthey
a hook
on the
swallowing. They feed on krill, fish, squid, crustaceans
andhave
smallasea
animals,
swallow
theirend,
preyperfect
whole. for grabbing
prey.
have spines
in they
theirdrink
throats
and this s
Penguins don't live near freshwater - at least none
thatThey
isn't frozen. Instead
saltwhich
water. point
Theydownwards
have a
their
mouths
they are
feed on
krill, fish, squid, cru
special gland in their bodies that takes the salt out
of the
waterwhile
they drink
and swallowing.
pushes it outThey
of grooves
in their
animals, and they swallow their prey whole. Penguins don't live near fre
beak.
How do they breed?
that isn't frozen. Instead they drink salt water. They have a special glan
takes the salt out of the water they drink and pushes it out of grooves in
How
do they
breed?
Penguins lay their eggs on land. Both the male and
female
penguins
prepare the nest. The female lays two eggs
and both parents take turns to sit on the eggs, so they can take turns to go and find food. The eggs hatch after 3040 days and both parents feed the chicks. When the chicks are born they have downy feathers. These feathers are
not waterproof so the chicks cannot swim.
Why must we protect penguins?
Nowadays, the world's penguin populations are under increasing pressure by human activity. Penguin populations
all over the world are being affected by things like global warming and by food reduction in areas where they breed.
Commercial overfishing of krill and fish on the Antarctic seas is putting increasing pressure on food chains and
food availability for penguin populations.
Penguins are also particularly vulnerable to oil spills; oil pollution kills tens of thousands of penguins every year.
But, amongst all the dangers, human-made global warming is by far the highest. The slightest change in seawater
temperatures affects ice cover and food availability.
Fun Activity
Penguin Waddle Relay
Divide the class into 2 teams. Place half of each team behind lines 5 to 8m apart, facing each other. Place a
rubber ball between the knees of the first two people in line and watch them waddle like penguins to give the
ball to their teammates behind the opposite line. The teammates then carry the balls back to the starting line
passing the ball to the next person waiting in line, and the waddling continues until everyone has had a turn. If
the ball is dropped, the penguin must go back to his/her starting point and begin again. The winning penguins
are those that can waddle the fastest without dropping the ball.
Sea Turtles
Sea (marine) turtles are some of the most ancient reptiles still on earth to
around for over 200 million years. Like other reptiles such as crocodiles,
turtles are cold blooded and live only in the warmer parts of the world. Th
Sea
Turtles
South
African
beaches are the loggerhead and leatherback turtle.
Sea (marine) turtles are some of the most ancient reptiles still on earth today and have been around for over 200
million years. Like other reptiles such as crocodiles,
lizards
snakes,
What do
theyand
look
like?turtles are cold blooded and live only in
the warmer parts of the world. The turtles that nest on South African beaches are the loggerhead and leatherback
turtle.
What do they look like?
Sea turtles have a flatter, lighter shell than tortoises have, and their front and rear
flippers are used for swimming; they are very good swimmers and divers.
They cannot pull their head and legs into their shells like tortoises.
Sea turtles have a flatter, lighter shell than tortoises have, and their front
used for swimming; they are very good swimmers and divers.
They
cannot
pull their
head and
into their
like tortoises..
Sea turtles are almost always underwater but
breathe
air. They
can quickly
refill legs
their lungs
whenshells
they come
to the
How do they breathe?
surface. Usually turtles dive for about 4 to 5 minutes and surface to breathe for 1 to 3 seconds, but they can rest or
sleep underwater for several hours at a time
What do they eat?
How do they breathe?
Depending on the species, sea turtles may be carnivorous (meat eating), herbivorous (plant eating), or omnivorous
(eating both meat and plants). The jaw structure of many species is adapted for their diet. Leatherbacks have
delicate scissor-like jaws for eating jellyfish and other soft-bodied animals. Loggerheads' jaws are adapted for
crushing and grinding, as they eat mainly crabs, molluscs, shrimps, jellyfish, and vegetation. Green sea turtles
have finely serrated jaws adapted for a vegetarian diet of sea grasses and algae.
How do they breed?
Adult females return to land to nest at night. They tend to return to the same beach where they were born. On
the beach the female digs a nest with her hind flippers. She lays up to 200 eggs with soft leathery shells. Before
going back into the sea, the female refills and covers the nest with sand. After about two months, the babies hatch
and dig through the sand; when they reach the surface, they head straight for the sea. Many of them are eaten by
predators such as seagulls and crabs before they even reach the sea.
Why must we protect turtles?
Turtles all over the world are declining in numbers. They face a huge range of threats to their survival, from the
moment the eggs are laid in the sand, through to adulthood. Apart from the threats posed by other creatures,
marine turtles are increasingly threatened by the actions of people throughout the world. In some areas, the eggs
of certain species are dug up and eaten, while adult turtles are killed for food. Other problems include destruction
of nesting beaches, disturbance of the nesting females, and accidental catching and killing of turtles in fishing nets.
In addition, turtles mistake plastic bags floating in the sea for jellyfish and eat them. This may choke them to death
or prevent them from eating properly.
Fun Activity
Turtle Maze
GHOST CRABS
NB Racoon to be replaced with ghost crab illustration
SUITED FOR THE SEA
ADAPTATIONS FOR LIFE IN THE SEA
Activity 1:
•
•
•
Choose an animal from the sea that you have learned about. On a piece of paper, write down all the basic things your animal needs to survive. Then make a list of all the things you need to survive. How are the lists the same? How are they different?
Draw a picture of your house, including what you need to live (water, food, place to sleep). Then draw a picture of your seashore animal.
o
What body parts help it survive?
o
What behaviours help it survive?
10
Draw in the animals’ “home” around it.
Does the animal need the same sort of things we need?
Activity 2:
•
Choose an animal from the sea that you have learned about.
o
Write a story about its life from the animal’s point of view.
o
What happens when a wave comes crashing in?
o
How does it protect itself?
o
How does it keep from drying out?
o
How does it find and catch food?
EXAMPLES OF FISH WITH SPECIAL ADAPTATIO
o
What happens if a predator comes along?
Rocksucker
EXAMPLES
OF FISH
SPECIAL
ADAPTATIONS
EXAMPLES
OFWITH
FISH
WITH
SPECIAL
ADAPTATIONS
EXAMPLES
OF FISH
WITH
SPECIAL
ADAPTATIONS
Rocksucker
Rocksucker
Rocksucker: ventral view (underneath)
Rocksucker: dorsa
Description: The pelvic fins of rocksuckers have been adapt
to be washed
waves. They are usually greenish in colour, mottled with brow
and can grow up to 30cm.
Description:
The pelvic
fins
of rocksuckers
have been
adapted
to form to
a form a
Description:
The
pelvic
fins of rocksuckers
have
been adapted
Rocksucker
“sucker” “sucker”
for holding
on
to
the
rocks
so
as
not
to
be
washed
away
by
the
for holding on toWhere
the rocks
so aslive:
not Rocksuckers
to be washedoccur
awayright
by the
do they
around our co
waves. They are usually greenish in colour, mottled with browns and pinks
waves.
They
are
usually
greenish
in
colour,
mottled
with
browns
and
pinks
found
mainly
in
tidal
pools.
Females
lay
up
to
500
eggs which
Description:
The
pelvic
rocksuckers have been adapted to form a “sucker” for holding on to the rocks
and can
grow
upfins
to of
30cm.
and
can
grow
up
to
30cm.
under
rocks
and
shells
in
the
tidal
pools.
so as not to be washed away by the waves. They are usually greenish in colour, mottled with browns and pinks
Rocksucker:
ventral viewventral
(underneath)
Rocksucker:
dorsal
viewso
“sucker” for holding
on to
the (top)
rocks
asview
not
Rocksucker:
view (underneath)
Rocksucker:
dorsal
(top)
Rocksucker: ventral view (underneath)
Rocksucker: dorsal (top) view
and can grow up to 30cm.
Where do
theydo
live:
Rocksuckers
occur
right
around
Where
they
live: Rocksuckers
occur
right
around
ourand
coast,
and are
What
do they
eat:
Theyour
eat coast,
limpets,
seaare
urchins,
chitons, small
found mainly
in
tidal
pools.
Females
lay
up
to
500
eggs
which
are
attached
found
mainly
in
tidal
pools.
Females
lay
up
to
500
eggs
which
are
attached
Where do they live: Rocksuckers occur right around the coast of South Africa, and are found mainly in tidal
under rocks
and500
shells
inwhich
the tidal
pools.
under
and
shells
inattached
the
tidal
pools.
Did
you
know:
has pools.
a clever strategy to capture
pools. Females lay
up torocks
eggs
are
under
rocksThe
androcksucker
shells in the tidal
fish waits until the limpet raises its shell slightly in order to move
What
they
eat:
They
eat
limpets,
sea shell
urchins,
chitons,
small
crustaceans
What do
theydo
eat:
Theydo
eatthey
limpets,
sea
urchins,
chitons,
small
crustaceans.
What
eat:
They
eat
limpets,
sea
urchins,
chitons,
small
at the
with
its mouth
open
and crustaceans
hooks its large upper tee
shell. The fish then twists its body round 180, forcing the limpe
Did
youThe
know:
rocksucker
has
clever
strategy
toThe
capture
limpets.
The
Did you
know:
rocksucker
hasThe
a clever
strategy
tohas
capture
limpets.
fishtowaits
until
the
limpet
raises
Did
youThe
know:
rocksucker
ais
clever
strategy
capture
limpets.
Theis passed un
Thea limpet
then
swallowed
whole
and
the
shell
fish
waits
until
the
limpet
raises
its
shell
slightly
in
order
to
move,
then
it
dives
its shell slightly infish
order
to move,
dives at
the
shell
with
its
mouth
open
and
hooks
its
large
upper
waits
until then
the itlimpet
raises
its
shell
slightly
in
order
to
move,
then
it
dives
mucoid capsule via the anus. The mouth teeth
and anus are
under the
shell.shell
The
fish
then
twists
its
body
round
180˚,
forcing
the
limpet
off the
rock.rocksucker
The
limpet
iscan
thenthe
at the
with
its
mouth
open
and
hooks
itshooks
large
upper
teeth
under
the
at the shell with its mouth
open
and
its
large
upper
teeth
under
considerable
expansion.
The
swallow surp
swallowed
whole
and
thethen
shelltwists
is passed
undigested
in a180,
mucoid
capsule
vialimpet
the anus.
The
mouth
and anus are
shell.
The
fish
itstwists
body
round
forcing
the
rock.
shell.
The
fish
then
its
body
180,
forcing
theoff
limpet
off the
rock.
limpets:
around
12 cm
fish the
was
found
with
a 3.1cm
pear
limpet inside it
capable
of considerable
expansion.
The rocksucker
canthe
swallow
surprisingly
large limpets: a in
12 acm fish was
The
limpet
then
swallowed
whole and
shellthe
is passed
Theislimpet
is then swallowed
whole
and
shell is undigested
passed undigested
in a
found with
a
3.1cm
pear
limpet
inside
it!
mucoid capsule via the anus. The mouth and anus are capable of
mucoid capsule via the anus. The mouth and anus are capable of
considerable
expansion.
The rocksucker
can swallow
surprisingly
large large
considerable
expansion.
The rocksucker
can swallow
surprisingly
Cardinalfish
limpets: limpets:
a 12 cm afish
was
found
with
a
3.1cm
pear
limpet
inside
it!
12 cm fish was found with a 3.1cm pear limpet inside it!
Cardinalfish
Cardinalfish
Cardinalfish
Description: These are small fish with two separate dorsal fins. The
body is oblong and slightly compressed; most species are nocturnal
(active at night).
Where do they live: They are common in the Indian ocean, from
Mozambique to Aliwal Shoal (KwaZulu Natal coast). They are mostly
found on shallow coral reefs; a few occur in estuaries.
Cardinalfish
What do they eat: Small benthic (bottom-dwelling) invertebrates and zooplankton.
Did you know: Cardinalfish are one of the few marine fish that incubate their eggs in their mouths. Once the
eggs are released and fertilized the male (or in some species the female), will take the eggs into his mouth
where they will be incubated until they have hatched. Once the male of this species has received the fertilized
eggs into his mouth he will not eat until the young (fry) have hatched, a process that can take up to 24 days.
During this time the female will aggressively chase away any other fish that come too close to the male. Even
after hatching, the fry remain in the male’s mouth for a few days before he spits them out to search for food.
before he spits them out to search for food.
Anglerfish
Anglerfish
Description: Anglerfish have a short, roundish body which is
slightly compressed; they have a large mouth; the gill opening is just
a small pore behind and below pectoral fin base. The first dorsal fin
and rod”
sub-tropical
Atlantic, from Senegal to Namibia and the R
spine at the front of the snout is modified as a “fishing
with a
Knysna.
fleshy bait at the tip in most species. They range in size from 3 to
Striped
anglerfish
(frogfish)
Striped
anglerfish
(frogfish)
36cm.
What do they eat: Anglerfish eat fish and, due to their large
mouth
and enormous
stomachs
they are able
totide
swallow fish
Where do they live: They are sedentary fish found
in shallow
water,
on soft
bottoms,
Description:
Anglerfish
have ina seagrass
short, beds,
roundish
body wh
themselves.
pools and reefs. They occur in the tropical and sub-tropical Atlantic, from Senegal to Namibia and the Red sea
compressed; they have a large mouth; the gill opening is jus
behind
andknow:
below pectoral
base.
The first
fin spinethem
at
Did you
Anglerfishfinare
capable
of dorsal
camouflaging
snout
is
modified
as
a
“fishing
rod”
with
a
fleshy
bait
at
the
tip
in
background
as enormous
a means stomachs
of escaping
What do they eat: Anglerfish eat fish and, due toresemble
their largetheir
distensible
mouth and
theypredators an
They
rangeThey
in size
to 36cm.
their prey.
lurefrom
their3prey
by means of using the modified dors
to Knysna.
are able to swallow fish larger than themselves.
like a fishing
rod and
bait. Prey
is divided
into three phase
Did you know: Anglerfish are capable of camouflaging
themselves
to resemble
theircapture
background
as a means
Where
do
theybymouth
live:
They
are the
sedentary
fish
found
shallow
in which
isofopened
with
lightning
speed
in th
striking
of escaping predators and to catch their prey. They
lure their
prey
means
using
modified
dorsal
fin toinsuck
bottoms,
inthree
seagrass
beds,
pools
and mouth
reefs.
the pr
strike is
much
faster
than
the tide
strike
of ina which
cobra!);
swallowing
spine like a fishing rod and bait. Prey capture is divided
into
phases:
stalking;
striking
isThey occur
expandable
sac-like
opened with lightning speed to suck in the prey (the
strike is much
fasterstomach.
than the strike of a cobra!); swallowing
the prey into the expandable sac-like stomach.
Flashlight fish
Flashlight fish
Description: Flashlight fish are about 10-14cm in length. The
body and fins of the flashlight fish are dark brown to grey-black
in colour. The snout is blunt. They have two big light organs, one
below each eye .
Flashlight fish
Flashlight fish
Where do they live: During the day flashlight fish are down in deep water (200-400m), but come up at night to
feed on coral reefs (they are nocturnal fish). TheyDescription:
are found in all Flashlight
tropical oceans.
fish are about 10-14cm in length. The bo
of the flashlight fish are dark brown to grey-black in colour. The sno
What do they eat: Flashlight fish eat small crustaceans
suchtwo
as shrimps,
krill. one below each eye .
They have
big lightand
organs,
Did you know: Flashlight fish produce light called
bioluminescence
(“living
light”) the
fromday
the light
organsfish
below
Where
do they live:
During
flashlight
are down in d
their eyes. These organs (photophores) contain light
producing
bacteria
which
shine
continuously.
But
the
(200-400m), but come up at night to feed on coral reefs (they ar
flashlight fish can “switch” their lights on and off by
moving
a membrane
across
the lightoceans.
organ (a bit like an
fish).
They
are found in
all tropical
eyelid).This light helps the flashlight fish attract and also search for prey. They can also use these lights to
avoid predators. When being chased, the fish darts
in one
with
lights on and
changes
course andsuch as sh
What
dodirection
they eat:
Flashlight
fish then
eat small
crustaceans
goes in a different direction with the lights off in that
way
avoiding
predators.
The
flash
and
dash
action
can be
krill
repeated up to 75 times a minute.
Did you know: Flashlight fish produce light called bioluminesce
light”) from the light organs below their eyes. These organs (ph
contain light producing bacteria which shine continuously. But th
fish can “switch” their lights on and off by moving a membrane acro
Kob
Illustration from Coastal Fishes of Southern
Africa by Heemstra & Heemstra
Dusky Kob Kob
Illustration by Elaine Heemstra
Dusky Kob
Description: Kob have an oblongDescription:
to slightly elongate
is somewhat
compressed.
The lateral
Kob body,
have which
an oblong
to slightly
elongate
body, line
which is
extends to end of the tailfin. Adults
are goldencompressed.
brown in colour
with
brownish
Theytogrow
1.8m
(75kg).
somewhat
The
lateral
line fins.
extends
endupoftothe
tailfin.
Adults
are golden brown in colour with brownish fins. They grow up to 1.8m (75kg)
Where do they live: Kob are found all along our South African coast from False Bay to Mozambique. They
Where
found
our
coast from
Bay to
are common in turbid estuaries and
in thedo
surfthey
zone;live:
also Kob
over are
rocky
reefs all
andalong
wrecks
associated
withFalse
sand to
Mozambique.
They
common
in
turbid
estuaries
and
in
the
surf
zone;
also
over
depths of 120m.
rocky reefs and wrecks associated with sand to depths of 120m.
What do they eat: Kob feed on fish, shrimp and squid.
What do they eat: Kob feed on fish, shrimp and squid.
Did you know: The dusky kob is the most important angling resource in the estuaries and surf zone for
Did anglers.
you know:
dusky kob
is ‘croakers’
the most or
important
angling they
resource
commercial anglers and recreational
TheyThe
are referred
to as
‘drums’ because
can in the
estuaries
and surf
anglers and recreational anglers.
produce a variety of sounds by means
of muscles
that zone
vibratefor
thecommercial
gas-filled swimbladder.
They are referred to as ‘croakers’ or ‘drums’ because they can produce a
variety of sounds by means of muscles that vibrate the gas-filled
swimbladder.
Sleeper ray: Electrolux addisoni
Sleeper ray: Electrolux addisoni
Description: The head, body and pectoral fins form a flabby, circular
disc. They have a large electric organ on each side of the head (this
is visible through the skin on the underside of the body). This ornate
sleeper ray is dark brown, covered in small yellow spots, and there are
several curved, black stripes on the disc.
Illustration
Where do they live: Ornate sleeper rays are endemic (found only) along the east coast of South Africa in
warm-temperate or subtropical waters and occur on shallow reefs. Description: The head, body and pectoral
They have a large electric organ on each
through
the that
skinthey
on the
What do they eat: Ornate sleeper rays eat small crustaceans, worms,
gastropods
suckunderside
up from theof the body
brown, covered in small yellow spots, and
sand or mud.
stripes on the disc.
Did you know: As in other electric rays, the electric organs can accumulate and store electricity similar to a
rechargeable torch battery. These powerful electric organs can deliver
a shock
up to 220
which sleeper
is used rays are
Where
doof they
live:volts
Ornate
to deter predators or stun prey. Predators quickly learn to avoid this electric
ray
with
its
conspicuous
colour
east coast of South Africa in warm-temperate
pattern and threat display.
on shallow reefs.
What do they eat: Ornate sleeper rays
gastropods that they suck up from the sand o
10
Did you know: As in other electric rays, the
and store electricity similar to a rechargeabl
electric organs can deliver a shock of up to
predators or stun prey. Predators quickly lea
its conspicuous colour pattern and threat disp
Sole
Sole
Description: The head and body of a sole are extremely
eyes are on right side of the head. They can grow up to 75
Sole
Sole
hiding
in sand
Sole
hiding
in sand
Sole hiding in sand
Where do they live: Soles are bottom dwellers (benthic),
sandy and mud bottoms from the shore down to 300m dep
Description: The head and body of a sole are extremely compressed. Both eyes are on right side of the head.
What do they eat: They feed on small crustaceans, m
They can grow up to 75cm in length.
brittlestars.
Where do they live: Soles are bottom dwellers (benthic), occurring mostly on sandy and mud bottoms from the
Did you know: A baby sole is born with eyes on each side
shore down to 300m depth.
the young are about one cm long, they undergo a chang
with oneworms
eye moving
across the top of the head to the oth
What do they eat: They feed on small crustaceans, molluscs,
and brittlestars.
Did you know: A baby sole is born with eyes on each As
sidean
of adult,
the head.
the side
youngbecomes
are about the
one underside,
cm
theWhen
“blind”
and
long, they undergo a change of body structure with onesea
eyebottom
moving for
across
topofofits
thelife.
head
to the
thethe
rest
The
fishother
can side
hide half-bur
of the body. As an adult, the “blind” side becomes the underside,
and the fish
lives on the sea bottom for the
avoiding passing
prey.
rest of its life. The fish can hide half-buried in the sand thus avoiding passing prey.
Seahorse
Seahorse
Description: The seahorse does not have scales - the body is protected by dermal
plates forming tubular rings. They have a small mouth at the end of a tubular snout
and they have no teeth. They have a prehensile tail which they can use to hold onto
seaweed. They are pale green, brown, black or speckled in colour, but can change
colour to bend in with their environment. They swim upright and are slow swimmers.
Where do they live: Seahorses are found world wide in shallow tropical or temperate
coastal waters and in estuarine and freshwater environments.
What do they eat: Seahorse adults eat small crustaceans and fish larvae, while the juveniles eat small
zooplankton.
Description: The seahorse does not have scales - the b
dermal
forming tubular
rings. The
They
have a small mo
Did you know: Seahorses are the only fish species where
the plates
male experiences
a “pregnancy”.
female
deposits the eggs in the male’s pouch and fertilization tubular
is internal.
The eggs
held
in the
and
therehave
is
snout
and are
they
have
nopouch
teeth.
They
a prehe
some evidence that oxygen is provided for the embryos.
The
male
the young They
and they
likegreen, brow
can
use
to gives
hold birth
ontotoseaweed.
arelook
pale
miniature adults.
in colour, but can change colour to bend in with their envir
upright and are slow swimmers.
Where do they live: Seahorses are found world wide in
temperate coastal waters and in estuarine and freshwater
11
NOTES
12