2. Objective:
Describe the diverse characteristics,
uses and roles in the environment
of sponges, cnidarians and
flatworms

6. Acoelomates :- NO Coelom -Eg
Platyhelminths
Pseudoceolomates :- body cavity not
lined by mesoderm but mesoderm is
found in patches between ectoderm &
endoderm - Eg Aschelminths
Coelomate:- eg – Annelid , arthropods
etc –having true Coelom
Coelom- A cavity between body wall
& gut wall by mesoderm

8. PHYLUM PORIFERA
SPONGES

10. Itroduction
 Porifera (po-rif -er-a) (L. porus, pore, fera,
bearing)
 Most primitive of all animals
 Among the approximately 15,000 sponge
species are mostly marine; a few exist in
brackish water, and some 150 species live in
freshwater
 Sessile; Draws food and water into its body

12. Characteristics
  Multicellular
 Body with pores (ostia) where water, canals,
and chambers that form a unique system of
water currents on which sponges depend for
food and oxygen
 Radial symmetry or none
 No organs or true tissues; digestion intracellular
 Excretion and respiration by diffusion

15. Phylum Cnidarian
Cnidarians

16. Introduction
The cnidarians (or coelenterates),
phylum Cnidaria (or Coelenterata),
are soft bodied animals that exhibit
radial symmetry and posses true
tissues

17. Characteristics
• the name: Cnidaria  from KNIDE
(nettle)
• Coelenterata  from COEL (cavity) +
ENTERON (gut)
• includes hydras, jellyfish, corals and sea
anemones
• aquatic (mostly marine, few fresh water
species)
• basic structure: hollow sac w/ single
opening (mouth) surrounded by tentacles
bearing stinging cells (cnidoblasts)

18.  exhibits radial symmetry
• diffuse nervous system  NERVE NET (nerve cells
distributed all over body)
•
• tentacles possess CNIDOBLASTS (stinging cells)
containing NEMATOCYSTS (w/ poison) for
defense and catching food
• gastrovascular cavity (coelenteron) is sac
shaped with one opening acting as both mouth
and anus  INCOMPLETE gut/digestive tract

21. Physalia
Sea fan
Brain coral Sea Anemone

22. Phylum Platyhelminthes
Flatworms

23. Introduction:
 In Greek Platys means flat, helmins means worm
 As there name says they are flat and ribbon like
organism.
 Bilaterally symmetrical, triploblastic and
acoelomate animals with organ level of
organization

24. Flatworms are found
in fresh water, in wet
places and marine
waters.

25. Planaria is an example of a free living
flatworm. It lives in moist surfaces under
rocks in ponds, rivers and even aquariums
 They include the free-
living or non-parasitic
worms, the parasitic
flukes, and the
tapeworm group

27. Flukes are parasites that
live in other animals
including humans

29. Tapeworm are also
parasitic flatworms.

33. Assessment
1-2 KINGDOM ANIMALIA consist of two big groups. Give
the two.
3. It is the simplest animals and either be asymmetrical or
symmetrical that can be found in salty and fresh water.
4. Sponge is under what phyla?
5. Members of Phylum Cnidarian consist of animals whose
tentacles contain stinging cells called?
6-7 Give at least two organism under phylum Cnidarians.
8. Flatworms belongs to what phyla?
9.An example of free living flatworms.
10. Platyhelminthes that live in other animals including

36. Characteristics
 Etymology:- From the Greek Nema for Thread
and Eidos for form
1)Bilaterally symmetrical, and vermiform.
2)Body has more than two cell layers, tissues and
organs.
3)Body cavity is a pseudocoel, body fluid under
high pressure.
4)Body possesses a through gut with a subterminal
anus.
5)Body covered in a complex cuticle.

37. 6)Has a nervous system with pharyngeal nerve
ring.
7)Has no circulatory system (no blood system)
8)Reproduction normally sexual and
gonochoristic.
9)Feed on just about everything.
10)Live just about everywhere, many species are
endoparasites.

38.  Usually classified into 5 main groups:
Bacterivores- bacteria eating
nematodes
Fungivores- fungus eating nematodes
Predators- eat other nematodes of the
same size.
Omnivores- eat more than one food
material
Unknown- food source has not been
determined yet.

39. Anatomy

40. Free Living Roundworms
 They serve as
decomposers in the soil in
both marine and fresh
water
 A lot of them can be
found in decaying
organic matter

41. Parasitic
 It can be found in moist
tissue of plants and
animals
 Human beings, along with
all other living things are
host to numerous
Nematode parasites.
Ascaris lumbricoides

42. Loa loa

43. Hookworm
Ancylostoma duodenale

44. Pinworms
Enterobius vermicularis

46. Characteristics
The annelids (also called "ringed
worms" or "segmented worms"),
formally called Annelida (from Latin
anellus "little ring"), are a large
invertebrate phylum, with over
17,000 modern species including
ragworms, earthworms and leeches.

47.  often hermaphroditic
 True coelom
 Digestive tract
 Why am I so unique?
 As an annelid, I am able to live in a variety of
places. I prefer underground, but sveral of my
cousins are able to live within sponges, or even
“shells” of their own creation!
 My body is divided into several “segments” that
can regrow if I lose one.
 They have nervous, circulatory, digestive
and excretory system.

48. We annelids are divided into three
classes: Oligochaeta, Hirudinea,
and Polychaeta.
Oligochaeta (earthworms) live
underground terrestrially in moist soil,
and come to the surface after heavy
rainfall.
Hirudinea (leeches) live near
freshwater streams, because of an
inability to store water very well.
Polychaeta (marine worms) live in the
ocean, filter-feeding for survival.

49. Polychaeta
 most marine species
is in this class
 either free-
swimming or
“fanworms”

50. Polychaeta
 fanworms are tube-
dwellers that have
tentacles for filter-feeding

51. Polychaeta
 free-swimming annelids have a pair of
parapodia on each segment
 usually powerful, pincherlike jaws:
(sandworms & clamworms)

52. Oligochaeta
The EARTHWORM

54. MOVEMENT:
1) posterior setae anchor
2) circular muscles
contract
3) anterior setae anchor
4) circular muscles relax
and longitudinal muscles
contract
*muscles contract against
“hydrostatic skeleton”

55. EXCRETION:
NEPHRIDIA - long tubules
that excrete liquid waste
• RESPIRATION &
CIRCULATION:
– no special resp. structures
– breathe through moist skin
– blood flows from anterior
(ventral blood vessel) to
posterior (dorsal blood
vessel)

57. • REPRODUCTION:
– are hermaphrodites
– cannot fertilize own
eggs
– young hatch in 2 - 3
weeks

58. Hirudinea
have no setae nor
parapodia
most are parasites
most dwell in fresh water
LEECHES

59. Hirudinea
one pair suckers
muscular pharynx w/ razor-sharp
teeth
anti-coagulant & pain-numbing
saliva

61. Hirudinea

63. Assessment:
Write whether Nematode or
Annelida
1. Earthworms
2. Pinworms
3. Segmented Body
4. Hirudinea
5. Leech
6. Polychaeta
7. Oligochaeta
8. Aceti
9. Hookworms
10. Loa-loa

64. Assignment:
On a ¼ sheet of paper.
1. How would you describe bivalves and
univalves?
2. How many openings does an Ascaris sp.
body have?

66. Review…..
Direction:
Tell whether it belongs to Phylum
PORIFERA, CNIDARIA,
PLATYHELMINTHES, NEMATODA or
ANNELIDA.

67. PHYLUM CNIDARIA

68. PHYLUM PLATYHELMINTHES

69. PHYLUM ANNELIDA

70. PHYLUM PORIFERA

71. PHYLUM NEMATODA

72. DIRECTION:
ARRANGE THE SCRAMBLED
WORDS.

73. L L E S H

74. T O P U S O C

75. ARTS SHIF

76. Objective:
Describes the diverse
characteristics, uses and
roles in the environment of
Mollusks and Echinoderms.

78. CHARACTERISTICS
 Mollusks are soft-bodied invertebrates with most
of them covered by a shell.
 Has complex respiratory, reproductive,
circulatory, digestive and excretory system.
 Its body has three important parts:
Foot- locomotion
Mantle- produces shell
Visceral mass – contains organs

79. Tree parts of the mollusks body

80. Three Classes:
Gastropods, Bivalves,
Cephalopods

81. Class Gastropods
 Also called as univalves( one shell)
 Commonly are marine with freshwater
(have gills) and terrestrial members (use the
lining in their mantle as lungs)
Sea slugs nudibranchs land slugs

82. Class Bivalves
 Consist of two shells attached to each other.
 Some can be seen attached on rocks while others remain
in the sand or mud.
 They use their mantle cavity to feed by trapping
suspended particles in the water and for gas exchange
Oysters clams mussels

83. Class Cephalopod
 They have internal skeleton.
 Chambered nautilus has external skeleton while others is
shell-less
 They are the most active, very fast moving using arms and
tentacles in catching prey
Squid cuttlefish octopus

85. Characteristics
 All echinoderms were found in Marine environment.
 Some echinoderms were rooted on sand, some burrows
in mud of deep or shallow waters

86. Characteristics
 Parts of them mostly radiates from the center of the body.
 They also have spines which are extension of their hard
calcium.
 Under the skin these form an internal skeleton called
endoskeleton

87. Characteristics
 Echinoderms has a water filled tubes that spread out from
the tube feet.
 Tube feet are used for getting food, moving around and
gas exchange

88. Characteristics
 Sea star has the ability to regrow (regeneration) .

89. Examples

90. Examples

91. Assessment
Direction:
Supply the correct answer.
Mollusk are 1.)____________ invertebrates with
most of them covered by 2.)______. The mollusks
body has three parts 3.)_______ for locomotion,
4.)_______ produces shell, 5.)_______ that contains
their internal organs. They are mostly found in
6.)_______.
All Echinoderms are found in the 7.)_______.
They also have spines which are extensions made
of hard 8.) _______, under the skin, these form an
internal skeleton called 9.)________. Sea stars have
the ability to regrow parts called 10.)__________.

92. Assignment
Study the next topic
Arthropods

94. Review…..
Direction:
Tell whether it belongs to Phylum
PORIFERA, CNIDARIA,
PLATYHELMINTHES, NEMATODA,
ANNELIDA, MOLLUSKA AND
ECHINODERMATA.

95. PHYLUM PORIFERA
I AM a pore bearing phylum.
The most primitive of all the animals.
I have the simplest structure of all animals.
I could be seen under water or in marine
environment

96. PHYLUM CNIDARIA
My basic structure is a hollow sac w/ single
opening (mouth) surrounded by tentacles
bearing stinging cells

97. PHYLUM ANNELIDA
 I am able to live in a variety of places. I prefer
underground, but sEveral of my cousins are
able to live within sponges, or even “shells” of
their own creation!
 My body is divided into several
“segments” that can regrow if I lose one

98. PHYLUM ANNELIDA
 We are divided into three classes:
Oligochaeta, Hirudinea, and Polychaeta.

99. PHYLUM ECHINODERMATA
 All OUR COUSINS IS found in Marine
environment.
 WE have spines which are extension of
their hard calcium.

100. PHYLUM ECHINODERMATA
 We have water filled tubes that spread
out from the tube feet.
 Tube feet are used for getting food,
moving around and gas exchange

101. PHYLUM MOLLUSCA
 We are soft-bodied invertebrates with
mostly covered by a shell.
 We have complex respiratory,
reproductive, circulatory, digestive and
excretory system

102. PHYLUM NEMATODA
We are bilaterally symmetrical, and
vermiform.
Body possesses a through gut with a
subterminal anus.
Our body covered in a complex cuticle.

103. PHYLUM PLATYHELMINTHES
 Bilaterally symmetrical, triploblastic and
acoelomate animals with organ level of
organization

104. PHYLUM PLATYHELMINTHES
 As OUR name says we are flat and ribbon
like organism.

105. Motivation:
A horrid monster hides from the day,
With many legs and many eyes.
With silver chains it catches prey,
And eats it all before it dies.
Yet in every cottage does it stay,
And every castle ‘neath the sky.

106. Objective:
DESCRIBE THE
CHARACTERISTICS OF
PHYLUM ARTHROPODA

108. V
A
R
I
E
T
Y

109. Hermit Crab
Fairy Shrimp
Centipede
Horseshoe
Crab

111. Size
What Is Different about Each of These Animals?
Color
Shape
Method of Movement

112. What Do These Animals Have In Common?
Jointed Legs
Exoskeleton
Segmented Body
Distinct Head
Compound Eyes
(most cases)

113. • Common throughout marine, freshwater,
terrestrial, and even aerial environments
GENERAL CHARACTERISTICS

114. Characteristics of Arthropods
Segmented
Jointed appendages
Hard external skeleton
3 parts-head, thorax, abdomen
(arachnids exception)
Exoskeleton-hard, external skeleton made
of chitin
Molting- shed old exoskeleton and
secrete a larger one, very vulnerable
after molting

115. • Complete digestive tract (mandible-
chewing or proboscis- sucking) with a dorsal
heart and a ventral nervous system
• Respiration through gills, trachea, book lungs
or body surface
• Sensory organs include antennae and hairs,
simple and compound eye
• Reproduces (mostly sexually), one to several
larval stage

116. • The muscle system is more or less
assisted by hydraulics originated from
the blood pressure created by the heart
• Respiration through gills, trachea, book
lungs or body surface
• With open circulatory system.
Haemolymph that contains
haemocyanin, a copper-based
oxygen-carrying protein

117. Body parts
 Ganglia-clusters of nerve cells along a nerve
cord
 Compound eyes-may facets each with their
own lenses, some have single lenses and some
have both
 Spiracles-holes in the exoskeleton that allow
gas exchange (book lungs in arachnids)
 Trachea-chitin lined tubes in spiracles

120. SUBPHYLUM - Trilobites
• CLASS TRILOBITA – Trilobites
SUBPHYLUM CHELICERATA
• CLASS ARACHNIDA – Spiders, Scorpions, Ticks
• CLASS MEROSTOMATA – Horseshoe crabs
• CLASS PYCNOGONIDA – Sea spiders
REPRESENTATIVE ORGANISMS:

121. SUBPHYLUM UNIRAMIA
• CLASS CHILOPODA – Centipedes
• CLASS DIPLOPODA - Millipedes
• CLASS INSECTA – Insects
• Class Branchiopoda – Brine shrimp

122. • CLASS CEPHALOCARIDA – Horseshoe shrimp
• CLASS MAXILLOPODA – Barnacles, and
Fish lice
• CLASS MALACOSTRATA – Lobsters, Crabs,
and Shrimps

123. Lobsters, Crabs and Shrimps
American
lobster
Homanus
american
us
Blue crab
Callinectes
sapidus

124. CRUSTACEANS
They have hard exoskeleton and
have mandible to bite and grind
food.
All crustaceans live in water with
the exception of the pill bug.
Aquatic crustaceans have gills for
breathing.
Most crustaceans are food to
humans

126. CLASS ARACHNIDA
Spiders, Ticks and Scorpions
Wolf spider
Lycosa tarentula

127. The Goliath Bird-
eating tarantula (Theraphosa blondi)
But can grow as much as 1 ft in
diameter!

128. Arachnids
 They have two body sections, most with four
pairs of legs and mouthparts called chelicerae
and pedipalps.
 They use book lungs to respire.
 Spiders with thin and flexible exoskeleton are
the largest members of the group.
 Mites and Ticks are parasitic arachnids
 Scorpions have a poisonous sting.
 Horsehoe crab oldest living arthropods.

132. CLASS CHILOPODA
Centipedes
Peruvian Giant

133. All centipedes are nocturnal predators
which live by actively hunting down insects
and other small animals.
They are found mostly in tropical forests, but
have also established themselves in
temperate forests, deserts, and human
habitations.
Most centipedes have between 15 and 30
pairs of legs, one pair on each body
segment.
Eggs hatch into larvae with four pairs of legs.
Each larva molts 5 or more times, with the
number of legs increasing with each. Fully
mature adults have 15 pairs.

135. CLASS DIPLOPODA
Millipedes
Harpaphe haydeniana

136. Millipedes do not bite, pinch or sting, but
may emit foul-smelling or irritating
defensive chemicals.
Diplopods have two pairs of legs per
segment (except for the first segment
behind the head). Each segment that
has two pairs of legs is a result of two
single segments fused together. Most
millipedes have very elongated
cylindrical bodies, although some are
flattened dorso-ventrally, while pill
millipedes are shorter and can roll into a
ball like a pillbug.

138. CLASS INSECTA
Ants, Beetles and Bugs
ORDER
HYMENOPTERA
Fire ant
Solenopsis
invicta
ORDER
ORTHOPTERA
Migrating locust
Locusta
migratoria
ORDER COLEOPTERA
Weevil
Beetle

139. MAJOR PARTS OF AN INSECT

140. LIFE CYCLES OF
SOME INSECTS

141. LIFE CYCLE OF A BUTTERFLY
(CLASS INSECTA ORDER LEPIDOPTERA)
(Larva)
Caterpillar
(Pupa)
Chrysalis

142. LIFE CYCLE OF A GRASSHOPPER
(CLASS INSECTA ORDER ORTHOPTERA)

143. MIMICRY AND CAMOUFLAGE
Mimicry - take on the appearance of (another
animal or plant) in order to deter predators
Camouflage - the natural coloring or form of an
animal which enables it to blend in with its
surroundings

144. ECOLOGICAL IMPORTANCE
• Serve as food source for both animals and
humans
• Aid in the propagation of plant species by
means of cross-pollination
• Control the population of some harmful
organisms
• Some act as scavengers or saprotrophs

146. Objective:
Describe the
characteristics of Phylum
Chordata

148. Unifying Themes
1. Chordate evolution is a history of innovations that is built
upon major invertebrate traits
• They display many of the basic traits that first evolved in
the invertebrates: bilateral symmetry, cephalization,
segmentation, coelom, "gut" tube, etc.
2. Chordate evolution is marked by physical and
behavioral specializations
• For example the forelimb of mammals has a wide range
of structural variation, specialized by natural selection
3. Evolutionary innovations and specializations led to
adaptive radiations - the development of a variety of
forms from a single ancestral group

149. Characteristics of the Chordates
 Notochord, dorsal hollow nerve cord, pharyngeal gill
slits, blocks of muscle, post anal tail

150. Characteristics of the Chordates
The notochord
• All chordate embryos have a notochord, a stiff but flexible
rod that provides internal support
• Remains throughout the life history of most invertebrate
chordates; among, present only in the embryos of
vertebrate chordates

151. Characteristics of the Chordates cont.
Dorsal Hollow Nerve Cord (=Spinal Cord)
• A fluid-filled tube of nerve tissue that runs the length of the
animal, dorsal to the notochord
• Present in chordates throughout embryonic and adult life

152. Characteristics of the Chordates cont.
Pharyngeal gill slits
• Pairs of opening through the pharynx
• Invertebrate chordates use them to filter food
• Juvenile fishes use them to them for breathing
• In adult fishes the gill sits develop into true gills
• In reptiles, birds, and mammals the gill slits are vestiges,
occurring only in the embryo

153. Characteristics of the Chordates cont.
Blocks of Muscle - Myotomes
• Surrounding the notochord and nerve cord are blocks of
muscle - myotomes
Postanal Tail
• The notochord, nerve cord, and the myotomes extend to
the tail
• Found at some time during a chordate's development
•......My VideosEMBRYONIC DEVELOPMENT_ THE
NOTOCHORD.mp4

155. Invertebrate Chordates

156. SubPhylum Urochordata
• Marine animals; some species are solitary, others are
colonial.
• Sessile as adults, but motile during the larval stages
• Possess all 5 chordate characteristics as larvae
• Settle head first on
hard substrates and
undergo a
dramatic
metamorphosis
(e.g., tail,
notochord, muscle
segments, and
nerve cord
disappear)

157. SubPhylum
Urochordata cont.
• Adult body is covered
by an outer envelope
or tunic; composed of
fibers of tunicin
embedded in a
mucopolysaccharide
matrix
• Tunic encloses a
basket-like pharynx,
that is perforated by gill
slits
• Tunicates are filter feeders; plankton is trapped in a sheet
of mucus and cilia later direct the food-laden mucus to the
stomach
• Water leaves the animal via an excurrent siphon

159. SubPhylum Cephalochordata
• Exclusively marine animals
• Although they are capable of swimming, they usually are
buried in the sand with only their anterior end being
exposed

160. SubPhylum Cephalochordata cont.
•All chordate characteristics are present
throughout their life history
• They are filter feeders: inside of the oral hood
is lined with cilia -wheel organ
• These cilia, plus cilia in the pharynx help
generate a water current
• Water and suspended food particles pass
through the oral hood, equipped with
projections called cirri that strain larger
particles
• Feed by secreting a mucous net across the
gill slits to filter out food particles that are
present in the water.

162. Difference between the two?
 Urochordata adults are sac-like and sessile. Larva have
a tail, a notochord, and other typical chordate traits,
but lose them after attaching to a surface and
becoming adults.
Cephalocordata (like amphioxus) do not have a sessile
adult stage. They have a notochord throughout their
lifecycle. They have no real brain, but there is a dorsal
nerve chord.
Urochordata are currently thought to be more closely
related to vertebrata.