Arthropods are different from all other animals
because they are eucoelomates with a hard,
segmented body. The phylum Arthropoda
(jointed-foot) consists of most of the known
animals and many are enormously abundant as
individuals. The general characteristics of the
arthropods include a hard exoskeleton called a
cuticle made up of chitin and proteins. This hard
exoskeleton gives the organism’s segmented
body protection and a place for muscle
attachment. Arthropods also have jointed
appendages that allow for specialized functions.
They have an organ system level or organization
and they are triploblastic. There are five
subphyla: Trilobita, Checlicerata, Crustacea,
Myriapoda, and Hexapoda.
Subphylum: Trilobita
This subphylum (like other
arthropods) have paired
appendages.
They are segmented
without any specialization.
This subphylum are all
extinct (Permian era –
250 mya)
Subphylum: Cheliceriformes
Cheliceriformes all have 6 pairs of
appendages. The first pair is modified into
chelicerae. The next pair are modified into
pedipalps. The last 4 pairs are walking
legs. These animals have one or two body
regions (cephalothorax and abdomen).
These animals do not have a mandible or
any antennae.
Class: Eurypterids
The Eurypterids
or water
scorpions are
animals that are
now extinct. They
were normally
marine and
freshwater
predators.
Class: Merostomata
These organisms
(horseshoe crabs) are
found in shallow coastal
waters. The first pair of
appendages are modified
into chelicerae but the
second pair is not
modified into pedipalps
like other cheliceriformes.
The Horseshow crab’s
larvae look similar to the
extinct trilobites.
Class: Pycnogonida
These organisms (sea
spiders) are usually found
in shallow coastal waters
and many polar oceans.
These animals often have
eight legs (like true
spiders) but may have
extra legs from their
segments being
duplicated.
These organisms include
spiders, scorpions, ticks,
and mites. Spiders
contain modified
chelicerae which are
used as fangs to inject
poison. They also have a
special gland that can
produce silk used for
webs, eggs, escape, and
courtship. Scorpions are
the first terrestrial
invertebrates. Their
pedipalps are modified
into pinchers and their tail
is modified into a stinger.
Ticks and mites are
parasitic.
Class: Arachnida
Subphylum: Crustacea
Crustacea have two pair of antennae.
Each appendage is biramous (two main
branches). They have mandibles. These
animals have two or three body regions
(cephalothorax and abdomen or head,
thorax, and abdomen). These animals are
mostly marine.
Isopoda
The isopods are the
most diverse
crustaceans. These
animals are found in
terrestrial, freshwater,
and saltwater
habitats.
Decapoda
The decapods
include many of
the familiar
crustaceans.
They are
mostly aquatic
species.
Copepoda
The copepods are
animals that are
among the most
numerous members
of the marine and
freshwater plankton
community.
Cirrepedia
Barnicles are animals
that are exclusively
marine, and tend to
live in shallow and
tidal waters, typically
in erosive settings.
Subphylum: Myriapoda
Myriapods all have appendages that are
uniramous (one main branch). The body is
long with a distinct head. The have one
pair of antennae. These animals also have
a mandible.
Class: Chilopoda
These organisms are
centipedes. They
have one pair of
jointed legs per
segment. They have
poison claws and are
predators.
Class: Diplopoda
These organisms are
millipedes. They have
two pair or jointed
legs per segment.
(Two segments have
fused together). They
are herbivores.
Subphylum: Hexapoda
Hexapods all have 6 appendages, each
pair are attached to a segment of the
thorax. The body consists of a distinct
head, thorax, and abdomen. They have
one pair of antennae. These animals also
have a mandible.
Class: Insecta
Insects are the
most diverse of
all arthropods.
They may have
been the cause
of angiosperm
diversity. Know
the orders that
are
demonstrated
here.
Arthropoda
Level of Organization
Tissue Layers
Digestive System
Excretory System
Circulatory System
Respiratory System
Nervous System
Body Cavity
Asexual Reproduction
Sexual Reproduction
Organ-system
Triploblastic
Alimentary Canal with
modified mouth parts
Nephridia
Open system with heart
Skin, gills, tracheae or book
lungs
Dorsal brain with ring
connected to ventral cords
True
Budding in some
Usually Dioecious
Phylum: Echinodermata
The word Echinodermata means “spiny skin”.
These animals demonstrate secondary radial
symmetry as adults (evolved from bilateral
symmetry back to radial symmetry) while the
larvae stage still exhibits bilateral symmetry.
They are probably more closely related to the
vertebrates because of their deuterostome
development. Unique to echinoderms is the
water vascular system used for locomotion,
feeding and food exchange.
Echinoderm Structures
(P 126 Figure 7.100)
Oral Side: Side with mouth
Arboral Side: side without mouth
Madreporite: opening into water vascular
system
Ambulacral Grooves: Radiating grooves that
contain tube feet
Pedicellariae: pincer-like organs on surface
(see compound microscope)
Papillae: skin gills
Echinodermata Classes
Class
Characteristics
Examples
Asteroidea
Pentaradial
symmetry
Sea stars
Ophiuroidea
Pentaradial
symmetry
Disk-shaped, no
arms, spines
Brittle stars
Holothuroidea
Cucumbershaped, no arms,
no spines
Sea cucumbers
Crinoidea
Sessile, arms
used for filterfeeding
Sea lillies
Echinoidea
Sea urchin
Class: Asteroidea
Sea stars have five
arms that radiate from
a central disc. They
have an open
ambulacral groove.
The madreporite is on
the aboral side. They
contain both
pedicellariae and
dermal branchiae.
Class: Ophiuroidea
They have five thin
arms radiating from a
central disc. They
have a closed
ambulacral groove.
The madreporite is on
the oral side. They do
not have pedicellariae
or dermal branchiae.
The Sea urchins have no
arms but have five rows
of tube feet. They contain
moveable spines. They
have closed ambulacral
grooves. They
madreporite is on the
aboral side. They contain
pedicellariae and dermal
branchiae. They have
specialized jaw-like
structures called an
Aristotle’s lantern.
Class:
Echinoidea
Class:
Holothuroidea
Sea cucumbers are
soft bodied animals
with ambulacral areas
with tube feet. They
have an internal
madreporite. They
have no pedicellariae
or dermal branchiae.
The sea lilies are
attached to the
substrate with
many branched
arms. They have
open ambulacral
grooves. They
have no
madreporite,
pedicellariae or
dermal branchiae.
Class:
Crinoidea
Bipinnaria Larvae
The larvae form is
evidence that this
phyla has evolved
radial symmetry from
a bilateral ancestor.
The larvae form is
used for dispersal.
Echinodermata
Level of Organization
Tissue Layers
Digestive System
Excretory System
Circulatory System
Respiratory System
Nervous System
Body Cavity
Asexual Reproduction
Sexual Reproduction
Organ-system
Triploblastic
Alimentary canal
Absent
Reduced if at all
Dermal branchiae, tube
feet, respiratory tree
No brain, nerve ring with
radial nerves
True
Regeneration
Dioecious
Phylum: Chordata
The Phylum Chordata
include animals that
sometime in their life
cycle have a notochord
(for muscle attachment),
a hollow dorsal nerve
cord (to send nervous
signals), pharyngeal slits
(various functions) and a
post-anal tail
(movement). The three
subphyla are
Urochordata,
Cephalochordata, and
Vertebrata.
29
Subphylum: Urochordata
The Tunicates or
Sea Squirts contain
only the pharyngeal
slits as an adult.
They are usually
sessile and use the
pharynx for filter
feeding.
30
Subphylum: Cephalochordata
The Lancelets contain
all four chordate
characteristics as an
adult. They are usually
found buried in the
sand off our coast.
They are considered to
be the closest relative
to vertebrates.
31
Subphylum: Vertebrata
The Vertebrates are
animals with
backbones. They
contain all four
chordate
characteristics as an
adult with some
modifications. They
are free-living.
32
What is a Fish?
Fish are aquatic
vertebrates that are not a
mammal, bird, or reptile
(It isn’t a monophyletic
group).
There are the five major
living groups of fish:
Hagfish (jawless)
Lamprey (jawless)
Cartilaginous Fish
Lobe-finned Fish
Ray-finned Fish
33
Superclass: Agnatha
The agnatha are animals
without jaws and most lack
paired appendages.
Hagfishes may also lack
eyes and a stomach. They
are scavengers that enter
natural openings on living
and dead fish and
mammals. Hagfish find their
prey by a sense of smell.
Hagfish can secrete large
quantities of slime or mucus
and can tie themselves into
a knot which can also help
release the slime.
34
Superclass: Agnatha
The agnatha are animals
without jaws and most lack
paired appendages. The
adult lamprey feeds by
attaching its mouth to a fish,
secreting an anticoagulant
into the host, and feeding
on the blood and tissues of
the host.
Lamprey swim upstream to
spawn. They are called
ammocoetes as larva and
are found in burrows. The
larva must go through a
metamorphosis to become
adults where the entire
digestive system must be
restructured.
35
Superclass: Gnathostomata
This superclass contains jaws which evolved
from skeletal supports of the pharyngeal
slits.
36
Class: Chondrichthyes
The class chondrichthyes all
lack true bone and have a
skeleton made of cartilage
which is not a primitive
characteristic. Their tough
skin is covered with placoid
scales. Males have a
structure called claspers
which aren’t seen in females.
The two subclasses in this
class are Elasmobranchii (the
sharks, skates, and rays) and
the Holocehphali (the ratfish)
37
Shark Reproduction
Male and female sharks can
easily be told apart. Male sharks
have claspers which are
extensions of the pelvic fins used
to transfer sperm. There is also
three different types of shark egg
development. They are:
Viviparity: the mother
feeds the “babies” by a
placenta
Oviparity: the mother
deposits eggs in the
ocean
Ovoviviparity: the eggs are
retained in mom but without
any nourishment from the
mother.
38
Order: Selachiformes
Great White Sharks
The Great White Shark
measures up to 20 feet and
can weigh up to 4200 lbs.
They usually eat large bony
fish, smaller sharks,
dolphins, seals, and sea
lions. They are found in
almost all coastal and
offshore waters between 54
to 75 degrees F. The Great
White has been labeled a
“man eater” but in the last
100 years more people
have been killed by dogs in
the U.S. than this shark.
39
Order: Selachiformes
Leopard Sharks
The Leopard Shark
measures up to 6.5 feet and
can weigh up to 40 lbs.
They usually eat bony fish,
crustaceans, worms, and
clams. They are found
along the coast from
Oregon to Baja California.
The leopard shark is
spotted as a juvenile in the
shallows but usually lose
their spots as they get
larger and move to deeper
water.
40
Order: Selachiformes
Whale Sharks
The Whale Shark is the
largest fish in the ocean
and measures up to 66
feet and can weigh up to
7500 lbs. They usually
are filter feeders eating
enormous amounts of
plankton. They are found
in along the coast from
Oregon to Baja
California. The Whale
shark can filter 6000
liters of water an hour.
41
Order: Selachiformes
Hammerhead Shark
The Hammerhead shark
measures up to 18 feet and
can weigh up to 1000 lbs.
They usually eat fish, rays,
other sharks, cephalopods
and crustaceans. They are
found in tropical and
subtropical waters along the
shorelines. The shape of
the head is thought to
spread their receptors
across a larger area making
them 10 times more likely to
detect prey.
42
Order: Batiformes
Skates and Rays
Both skates and rays are
flat bottom-dwelling
organisms.
Skates have a tiny caudal
fin with no stinging
spines, each pelvic fin is
divided into two lobes and
lay egg cases.
Rays have a slender
whip-like tail with stinging
spines, each pelvic fin
contains one lobe and
give live birth.
43
Broad Skate
The broad skate is
known to grow to be
just under a meter in
length. It is a deepwater skate found in
the central and
northern Pacific
ocean. They feed on
mollusks,
crustaceans and
fishes.
44
Manta Ray
The manta ray is the largest
of the rays, with the largest
known specimen having
been about 7.6 m (about 25
ft) across. It ranges
throughout all tropical
waters of the world, typically
around coral reefs. Manta
rays are believed by some
to have evolved from
bottom-feeding ancestry,
but have adapted to
become filter feeders in the
open ocean
45
Guitarfish
The guitarfish are
mainly found in tropical
and temperate waters,
traveling in large
schools. Most adult
guitarfishes reach five
or six feet in length.
These fish are bottom
feeders, preferring
small crustaceans.
46
Order: Chimaeriformes
Chimaeras
Chimaeras differ from sharks in
that their upper jaws are fused
with their skulls; they have
separate anal and urogenital
openings; and they lack the
many sharp and replaceable
teeth of sharks, having instead
a few large permanent grinding
tooth plates. They are often
called ratfish or rabbit fish.
They are found in cold water
often at great depths. The diet
consists primarily of benthic
invertebrates. The tooth plates
are used to crush hard-bodied
prey such as crabs, clams, and
echinoderms.
47
The “Osteichthyes” all have a
skeleton made of true bone.
Their skin is covered with
ctenoid scales. They also
have an operculum (a hard
covering over the gills), which
helps them breathe without
having to swim. They also
have a swim bladder which
helps the body create a
neutral balance between
sinking and floating. There
are two classes in this group:
the Class: Sarcopterygii, the
Lobe-finned fish and the
Class: Actinopterygii the Rayfinned Fish
Osteichthyes
48
Sarcopterygii – Lobe-finned Fish
Subclass: Coelacanthimorpha
Coelocanths are lobe-finned fish
with the pectoral and anal fins on
fleshy stalks supported by
bones, and the tail is divided into
three lobes. Coelacanths also
have a special electroreceptive
device called a rostral organ in
the front of the skull, which
probably helps in prey detection.
Coelacanth populations have
been found near Indonesia and
South Africa. Coelacanths are
opportunistic feeders, hunting
cuttlefish, squid, snipe eels,
small sharks, and other fish.
49
Sarcopterygii – Lobe-finned Fish
Subclass: Dipnoi
Lungfish are fresh water lobefinned fish. Lungfish are bestknown for retaining primitive
characteristics, including the
ability to breathe air, Today, they
live only in Africa, South
America, and Australia. African
and South American lungfish are
capable of surviving seasonal
desiccation of habitats by
burrowing into mud and
estivating throughout the dry
season. They have a diet of fish,
insects, mollusks, worms,
crustaceans, and plant material.
50
Infraclass:
Holosteri
In this infraclass, all of
the fish are considered
to be primitive fish.
They are found in
brackish conditions.
They can use their
swim bladders to obtain
extra oxygen
51
Infraclass: Holosteri
Order: Lepisoteriformes
Gars inhabit fresh, brackish, and
occasionally marine, waters of
eastern North America, Central
America, and the Caribbean
islands. They have a swim
bladder that opens to the
pharynx that can function as a
lung and most gars surface
periodically to take a gulp of air,
doing so more frequently in
stagnant or warm water when
the concentration of oxygen in
the water is low
52
Infraclass: Holosteri
Order: Amiiformes
Amia's are also called Bowfin or
Dog fish. Amia’s distribution is
restricted to eastern North
America. Amia's swim bladder
functions much like a lung,
allowing this fish to gulp air when
dissolved oxygen levels become
dangerously low in the weed
beds where it lives.
They are primarily fish eaters,
although crayfish can make up a
substantial proportion of the diet,
and frogs are also consumed.
53
Infraclass: Teleostei
In this infraclass, all of the
fish are considered to be
the ray-finned fish. They
have a movable maxilla
and premaxilla and
modified muscles that allow
them to have a protrusable
mouth.
54
Infraclass: Teleostei
• Superorder: Osteoglossomorpha
– Bony Tongued fish
• Superorder: Elopomorpha
– Snake-like scale-less fish
• Superorder: Clupeomorpha
– Physostomes, which means that the gas bladder
has a pneumatic duct connecting it to the gut.
They typically lack a lateral line
• Superorder: Ostariphysi
– Their first few vertebrates are used to pass sound
from the swim bladder to the inner ear for acute
hearing
55
Infraclass: Teleostei
• Superorder: Protacanthopterygii
– These are fish that lack specialization
• Superorder: Stenopterygii
– Deep water fish. Bioluminescent
• Superorder: Scopelomorpha
– Deep water fish. Bioluminescent. They have
large eyes and adipose fins.
• Superorder: Acanthopterygii
– They usually have a Pelvic fin spine present.
56
Superorder:Osteroglossomorpha
Order: Osteoglossiformes
Arowana are freshwater
bony fish. They have a
unique structure called a
“bony tongue”. This is
actually derived from a
toothed bone on the floor of
the mouth and bite against
teeth on the roof of the
mouth. They can obtain
oxygen from the air by
sucking it into the swim
bladder which is lined with
capillaries.
57
Superorder: Elopomorpha
Order: Anguillidiformes
Morey Eel’s are found
in all tropical seas
usually in shallow
water with their body
wedged in a crevice.
Morey eels primarily
eat other fish and
mollusks. Their mouth
is often open (and
moving) to help water
circulate through the
gills
58
Superorder: Clupeomorpha
Order: Clupeiformes
The anchovy is a small green
fish with blue reflections due to a
silver longitudinal stripe that runs
from the base of the caudal fin.
They are found in the oceans
worldwide. Anchovies exhibit a
special way of feeding called
planktivory. These fish swim
through the water with their large
mouths open and strain out small
organisms (plankton) with fine,
sieve-like structures called gill
rakers.
59
Superorder: Clupeomorpha
Order: Clupeiformes
The sardines are a fish
found worldwide (but
named after an island in
the Mediterranean).
They are also called
pilchards. Sardines are
packed with nutrients
(omega-3 fatty acids,
Vitamin D, Calcium, B12, and protein).
60
Superorder:Ostariophysi
The superorder: Ostariophysi are fish that
have two main characteristics: they release
an alarm substance and their first few
vertebrates are used to pass sound from
the swim bladder to the inner ear for acute
hearing.
In this lab it includes the 1) Loachs, 2)
Characins, 3) Knifefish, and 4) Catfish
61
Superorder: Ostariphysi
Order: Cypriniformes
The Loaches are small
benthic freshwater fish.
Loaches are mostly
scavengers and are
omnivorous, usually not
very picky about their food.
Many live in waters of
generally poor quality and
some have adapted to
less-than-ideal water
conditions by being able to
gulp up atmospheric
oxygen from the air.
62
Superorder: Ostariphysi
Order: Characiformes
Piranha are carnivorous fresh
water fish living in South
American Rivers. They are
normally only 6-10 inches long.
They are known for their sharp
teeth and an aggressive appetite
for meat. They generally pose
no threat to humans. Humans
frequently swim in piranhainfested waters without attacks.
Their aggressiveness may
increase due to limited food but
rarely do they eat animals much
larger than themselves. They
have similar abilities to sharks to
detect blood in the water.
63
Superorder: Ostariphysi
Order: Characiformes
Hatchet Fish are a deep sea fish
that get their name from their
thin, hatchet-shaped body. Like
other deep sea fish, they have
the ability to create their own
lighting process known as
bioluminescence. Since the
photophores (organs producing
light) point downward, it is
believed they use them for
counter illumination to avoid
predators from below.
64
Superorder: Ostariphysi
Order: Cymnotiformes
The Knife fish are
primarily freshwater
inhabitants and have
organs derived from
muscle cells that are
adapted to the
generation of electric
fields.
65
Superorder: Ostariphysi
Order: Siluriformes
The Catfish are named for their
prominent barbels, which give
the image of cat-like whiskers.
Unlike other fish, There are
armour-plated types and also
naked types, neither having
scales. The glass catfish are
transparent because, like all
catfish they do not have scales
and they also don't have body
pigment. The glass catfish turns
milky white when dead,
suggesting it does something
during its life to keep it
transparent
66
Superorder: Protacanthopterygii
The Superorder: Protacanthopterygii are
fish that lack specialization. They are
important game fish
In this lab it includes 1) Salmon, 2) Pike and
3) Smelt
67
Superorder: Protacanthopterygii
Order: Salmoniformes
Salmon are typically
anadromous: they are born
in fresh water, migrate to
the ocean, then return to
fresh water to reproduce.
Both Atlantic and Pacific
Salmon are important to
recreational fishing around
the world. Currently in
California, Salmon fishing
has been suspended
because the numbers of
fish are dangerously low.
68
Superorder: Protacanthopterygii
Order: Salmoniformes
Trout are found in the
subfamily along with
salmon. Trout have fins
entirely without spines, and
all of them have a small
adipose (fatty) fin along the
back, near the tail. Trout
are found in clear streams
and lakes but are often
anadromous (like salmon).
69
Superorder: Protacanthopterygii
Order: Esociformes
Pike have the elongated,
torpedo-like form of
predatory fishes, with
sharply-pointed heads and
sharp teeth. They devour
fish up to one-third of their
own size. Pike are
cannibalistic; some 20% of
their diet consists of pikes
smaller than themselves.
Pike have little respect for
relative size and as a result
have been known to bite
swimmers and divers.
70
Superorder: Protacanthopterygii
Order: Osmeriformes
Smelt are small
anadromous fish. Smelt
has a character odor,
similar to the smell of
cucumbers. Smelt roe is
bright orange in color, and
is often used to garnish
sushi.
71
Superorder: Stenopterygii
Order: Stomilliformes
Dragonfish are among the
fish known as deep water
fish. Like other deep water
fish, they are capable of
bioluminescence. Unlike
other bioluminescent
creatures, they can glow
and perceive a red or bluegreen light (most species
only perceive blue light)
which allows it to see its
prey before they are seen.
72
Superorder: Scopelomorpha
Order: Myctophiformes
The lantern fish are found
in the deep sea. Like
other deep water fish,
they are bioluminescent.
They are a very common
deep water fish and they
make up about 65% of
the deep sea biomass.
73
Superorder: Scopelomorpha
Order: Myctophiformes
The Superorder: Acanthopterygii are
fish that have spiny fins.
In this lab it includes the rest of the fish in
lab.
74
Superorder: Acanthopterygii
Order: Mugiliformes
Mullet are ray-finned fish
found worldwide in coastal
temperate and tropical
waters, and in some
species in fresh water.
Mullets have served as an
important source of food.
Mullet does not keep well
after it is caught. If kept on
ice it may remain edible for
approximately 72 hours.
75
Superorder: Acanthopterygii
Order: Antheriniformes
Silversides are ray-finned
fish which usually have two
dorsal fins, the first with
flexible spines, and an anal
fin with one spine at the
front. The lateral line is
typically weak or absent.
Mosquito fish may now be
the most widespread
freshwater fish in the world,
having been introduced as
a biocontrol (to control
mosquitoes).
76
Superorder: Acanthopterygii
Order: Antheriniformes
Grunion are famous marine
bony fish found spawning on
the sandy beaches of
southern California. At night,
from March through
September, females burrow
backwards in the sand to lay
their eggs just after the
highest tides. They occur on
the second through fourth
nights after the full or new
moons. Each female is
accompanied by several
males which come to fertilize
the eggs.
77
Superorder: Acanthopterygii
Order: Beloniformes
Flying fish are a marine
fish. Their most striking
feature is their pectoral
fins, which are
unusually large, and
enable the fish to take
short gliding flights
through the air, above
the surface of the
water, in order to
escape from predators.
78
Superorder: Acanthopterygii
Order: Cyprinodontiformes
Desert Pupfish are an
endangered species
due to introduced
species and habitat
destruction/fragmentati
on. Desert pupfish are
well-adapted to the
rapid water temperature
changes (can tolerate
from 50-100 degrees F)
and high salinity they
experience in their
habitat.
79
Superorder: Acanthopterygii
Order: Stephanoberyciformes
Ridgeheads are also known as
bigscales, are a small, deepsea fish. These fish are named
for their large scales and
pronounced cranial ridges. The
family is sometimes termed
pseudoceanic because, rather
than having an even
distribution in open water,
ridgeheads occur in
significantly higher abundances
around structural oases,
notably seamounts and over
continental slopes.
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Superorder: Acanthopterygii
Order: Gobiesociformes
Clingfishes are ray-finned
fish where in most species
the pelvic fins are modified
into a sucking disc. Most
species are marine, being
found in shallow waters of
the Atlantic, Pacific and
Indian Oceans.
81
Superorder: Acanthopterygii
Order: Gasterosteiformes
Sticklebacks are ray-finned
fish that have no scales,
although some species
have bony armour plates.
They are closely related to
pipefish and seahorses.
Niko Tinbergen's studies of
the behaviour of this fish
were important in the early
development of ethology as
an example of a fixed
action pattern.
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Superorder: Acanthopterygii
Order: Synganthiformes
Sea Horses and Pipefish
are notable because they
are the only species in
which males become
“pregnant”. The males
have brood pouches which
the female uses an
ovipositor to deposit the
eggs. It is believed that the
pouch regulates salinity for
the eggs. These fish are
recognizable because of
their shape They have this
shape to help them hide in
the sea grass.
83
Superorder: Acanthopterygii
Order: Tetradontiformes
Porcupine fish are
recognizable for their
shape. They are often
confused with puffer fish
but porcupine fish have
spines. They blow up like
this to avoid predators.
They get this shape by
swallowing water (or air)
which limits what can eat
them.
84
Superorder: Acanthopterygii
Order: Tetradontiformes
Cowfish are recognizable for
their shape. They look this way
because The hexagonal platelike scales of these fish are
fused together into a solid,
triangular, box-like carapace,
from which the fins and tail
protrude. Because of these
heavy armoured scales, Cowfish
are limited to slow movements,
but few other fish are able to eat
the adults.
85
Superorder: Acanthopterygii
Order: Pleuronectiformes
Halibut are flatfish from
the family of the righteye flounders. When
the Halibut is born the
eyes are on both sides
of its head so it has to
swim like a salmon.
After about 6 months
one eye will migrate to
the other side of its
head so they lay on the
bottom for camouflage.
86
Superorder: Acanthopterygii
Order: Scorpaeniformes
Sculpin are bottom
feeders that are
generally not
considered good to eat,
and have sharp spines
rather than scales.
They use their large
pectoral fins to stabilize
themselves on the floor
of flowing creeks and
rivers.
87
Superorder: Acanthopterygii
Order: Perciformes
Girabaldi are California’s
State Marine Fish. They
are found in the Pacific
Ocean from Monterey Bay
to Baja California. They
are associated with reefs
and rocky sea-bottoms.
They eat mostly
invertebrates off the rocks.
They have the ability to
change their sex multiple
times during their life to
level out the ratio of males
to females.
88
Superorder: Acanthopterygii
Order: Perciformes
Striped Marlin are large
oceanic fish that can reach
nearly 12 feet and can
weigh up t0 450 lbs. They
are found in the tropical
and subtropical waters of
the Pacific and Indian
oceans. They are built for
speed in the open ocean
feeding on mackerel,
sardines, anchovy, squid
and crab near the surface.
89
Superorder: Acanthopterygii
Order: Perciformes
Wrasses are exclusively marine
in distribution usually in shallow
water habitats such as coral
reefs and rocky shores. The
Sheepheads are found in kelp
beds, on coral reefs and among
sea grasses. Its strong teeth
make this fish an opportunistic
predator. Sheephead wrasse
establish their own feeding patch
which is dominated by one male.
When he dies, one of the older
and larger females in the group
(around 30cm) changes colour
and turns into a male.
90
Superorder: Acanthopterygii
Order: Perciformes
Ocean Sunfish are the
heaviest known bony fish in
the world. It has an
average adult weight of 1
ton. Sunfish live on a diet
that consists mainly of Sea
jellies. As this diet is
nutritionally poor, they
consume large amounts in
order to develop and
maintain their great bulk
91
Superorder: Acanthopterygii
Order: Perciformes
Clownfish all form
symbiotic relationships with
sea anemones. The
clownfish feeds on
undigested matter which
otherwise potentially could
harm the sea anemone,
and the fecal matter from
the clownfish provides
nutrient to the sea
anemone.
92
Osteichthyes (External)
Fish have a torpedo shape which allows them to
reduce drag while swimming through the water.
They also have the following structures:
Ctenoid scales: embedded in the skin
Eyes: located on the sides with no eyelids and they do not have
binocular vision.
Lateral line: sensitive to pressure changes
Operculum: Hard covering over gills
Skeletal System: axial (skull and verebrae) and appendicular
(girdles and fins) which are very flexible for swimming
93
Osteichthyes (External)
Fish have many different fins:
Pectoral fins: Lift
Pelvic fins: Lift
Anal fins: Stability
Dorsal fins: Stability
Caudal fins: Propulsion
94
Osteichthyes (Internal)
System
Structure
Function
Muscular
Myomeres
Small contractions
Digestive
Stomach
Chemical Digestion
Pyloric Ceca
Increases SA
Intestine
Absorption of nutrients
Liver
Storage, conversion, removes toxins
Pancreas
Secretes enzymes
Spleen
Immune response
Kidneys
Filtration
Urinary Bladder
Holds Urine
Sinus venosus
Receives venus blood
Atrium
Pumps blood into ventricle
Ventricle
Pumps blood into body
Bulbus arteriosus
Maintains even blood flow
Excretory
Circulatory
95
Osteichthyes (Internal)
System
Structure
Function
Respiratory
Gills
Gas Exchange
Nervous
Brain
Nervous system control
Spinal Cord
Nervous signals
Ovaries
Produce Eggs
Testis
Produce Sperm
Swim Bladder
Buoyancy
Reproductive
Swim Bladder
96