From microscopic Amoeba to pentamerous Star fish...... really astonishing.....

1. ANIMALS HAVING NO BACKBONE

2. What is an Invertebrate?
Invertebrates are animals that do not have
backbones.
 97% of the animal kingdom is made up of
invertebrates.
Some can be found in ponds, oceans, and other
water environments.
.

3. Animal Characteristics
Many-celled organisms sharing similar
features and that are made of different
kinds of cells.
Animal cells have a nucleus and
organelles surrounded by a membrane –
EUKARYOTIC.
Cannot make their own food –
HETEROTROPHIC – digest their food.
Can move from place to place to find food,
shelter, and mates, and to escape from
predators.

4. Symmetry
Symmetry: arrangement of the individual
parts of an object
Radial: body parts arranged in a circle
around a central point
Bilateral: parts are mirror images of each
other
Asymmetrical: bodies cannot be divided
into matching halves

5. Symmetry

6. Major Phyla
INVERTEBRATE
Porifera Helminthes
CnedariaProtozoa
Echinoderm
Arthropod Molluscs
Annelids

7. Characteristics of
Phylum
Protozoa

8. 1.They are unicellular with some
colonial and multicellular stages.
2. Most are microscopic.
3. All symmetries are present within
members of the group.
4. No germ layers are present.
5. No organs or tissues are formed,
but specialized organelles serve many
of these functions.

9. 6.They include free-living,
mutualistic, commensal and
parasitic forms.
7.They move by pseudopodia,
flagella, cilia and they can direct
cell movements.
8.Most are naked, but some have
a simple endoskeleton or
exoskeleton.

10. PARAMECIUM
Paramecium is a
small unicellular
organism.
It is plentiful in
freshwater ponds.

11. macronucleus
micronucleus
oral groove
gullet
contractile
vacuole
food
vacuole
cilia
pellicle
anal pore
cytoplasm:
ectoplasm
endoplasm

12. Paramecium Movement
The outer surface of the cell is
covered with many hundreds of tiny
hair-like structures called cilia.
These act like microscopic oars to
push through the water, enabling the
organism to swim.
If Paramecium comes across an
obstacle, it stops, reverses the
beating of the cilia, swims backwards,
turns through an angle and moves
forward again on a slightly different
course.
It moves so quickly that we have to
add a thickening agent or quieting
solution to the slide to slow it down
to study it.

13. Paramecium Feeding
Paramecium has a permanent feeding
mechanism, consisting of an oral groove and
a funnel-shaped gullet into which food is
drawn by the combined action of cilia which
cover the body and other cilia lining the oral
groove and the gullet.
As it moves through the water it rotates on its
axis and small particles of debris and food are
collected and swept into the gullet.
They feed on small organisms such as
bacteria, yeasts, algae and even other
smaller protozoa.

14. Paramecium Reproduction
In favourable conditions the
cell divides in two by a
process called binary fission
(asexual reproduction).
This forms two new cells,
each of which rapidly grows
any new structures required
and increases in size.
This whole process may take
place two or three times a
day if conditions were right.

15. Paramecium Reproduction
This is a more complicated
method called conjugation
(sexual reproduction).
It involves two cells coming
together to exchange nuclear
material.
The two cells then separate
and continue to reproduce by
simple division.
It is similar in some ways to
sexual reproduction in more
complex animals.

16. Paramecium Excretion
Food waste left in a food
vacuole is excreted through
the anal pore (the vacuole
and pore fuse.
Other wastes left over from
cellular activity (metabolic
waste) simply diffuse
through the pellicle.
Excess water and some
metabolic wastes are
excreted through the
contractile vacuole.

17. Porifera: Sponges

18. Porifera Characteristics
They live in water. (Most are found in the ocean.)
They look like plants but they are animals.
Sponges stay fixed in one place - SESSILE.
Their bodies are full of pores and their skeleton
is made of spiky fibers (spicules) or rubbery
spongin
Sponges are divided into classes according to the
type of spicule they have – 5,000 species
identified!
Water flows through the pores of their body,
aided by flagella, which enables them to catch
food – FILTER FEEDERS

19. Porifera Characteristics
Sponges can reproduce asexually through
budding ~ GEMMULES; a new sponge grows
from pieces of an old sponge
Most sponges that reproduce sexually are
hermaphrodites, meaning they have both eggs
and sperm
Sperm is released into water
Sperm floats until they are drawn into another
sponge where they fertilize an egg
Larva develops in sponge, leaves sponge, and
settles to the bottom where it grows into an adult

20. 12-20
Sessile Sponges - do not move

21. General Morphology
• The internal cavity is called the atrium or spongocoel
• Water is drawn into it through a series of incurrent pores or dermal ostia present in the
body wall into a central cavity and then flows out of the sponge through a large
opening at the top called the osculum

22. Body layers
1. The pinacoderm - an outer layer of
flattened cells called pinacocytes
2. An inner lining containing flagellated cells
(choanocytes) - draw water in through the
pores and move out through the osculum; also
trap food particles
• The water current is also used for gas
exchange, removal of wastes, and release of
the gametes
3. Between the pinacodern and the
choanocytes is a gelatinous material called
mesenchyme;
Archaeocytes are amoeboid cells and they
can also undergo differentiation to form other
cells(Totipotency)

23. The Skeleton
In the mesenchyme is the skeleton composed of tiny pointed structures
made of silica or calcium carbonate called spicules.
These structures act as an internal scaffolding, but also function in
protection
Among some sponges the skeleton consist of spongin fibers made of
collagenous material; found in many of the commercial sponges

24. 12-24

25. Types of Canal Systems
ASCON TYPE
• Simple vaselike structure
• This stucture puts limitations on
size; (increase in volume without a
corresponding increase in the
surface area of the choanocytes)

26. SYCON TYPE
• The flagellated choanocyte layer
has undergone folding forming
finger like projections
• There is a single osculum but
the body wall is more complex,
with water being received
through incurrent canals, which
pass it along to radial canals
through to the spongocoel
• Results in an increase in the
surface area which allowed
sponges to increase in the size

27. LEUCON TYPE
• No atrium; several small
chambers in which choanocytes
are located
• There is a whole series of
incurrent canals leading to the
choanocyte chambers; water is
discharges through excurrent
canals
• The leuconoid sponges exhibit a
significant increase in surface
area and are, therefore, among the
largest sponges

28. 12-28
3 Sponge
Structures

29. Types of Porifera Cells
12-29

30. 12-30
Food Trapping by Sponge Cells

31. MODE OF REPRODUCTION
Asexual reproduction can occur by bud
formation
External buds
Small individuals that break off after
attaining a certain size
Internal buds or gemmules
Formed by archaeocytes that collect in
mesenchyme
Coated with tough spongin and spicules
Survive harsh environmental conditions
12-31

32. 12-32
Gemmule- Internal Bud

33. Sexual Reproduction
Most are monoecious (have both sexes)
Sperm and eggs sometimes arise from
choanocytes or archaeocytes
12-33

34. 12-34
DEVELOPMENT

35. Cnidaria: Corals, Hydras, and Jellyfish

36. Basic Characteristics
A. Tissue level
1. Sac – like body with 3 layers
a. epidermis
b. mesoglea
c. gastrodermis
2. Gastrovascular cavity –
hollow internal body cavity
B. Nervous system
1. Nerve net – nerves evenly
spaced
2. Statocysts – structures for
balance (hollow ball of cells
with a grain of sand)
3. Ocelli – light sensitive
structure

37. Taxonomic Characteristics
Diploblastic
Epiderm & hypoderm
Tissues

38. C. Tentacles
1. Capture food
2. Cnidoblast/cnidocyte – cell
that contains the stinging
organelle
3. Nematocyst – stinging organelle
a. capsule with coiled
“harpoon” containing
toxins
b. Operculum – flap that
holds the coil inside
c. Stimulated by touch and
chemicals

39. Everted nematocyst

40. D. Habitat
1. Mostly shallow, marine
2. Pelagic – open water
3. Benthic – bottom dweller
4. Symbiosis
a. on other animal’s shells
b. with algae that provide
energy from
photosynthesis

41. E. Reproduction
1. Polymorphism “many
shapes”
2. Polyp – sessile, tentacles up
3. Medusa – floating, tentacles
down
4. Many alternate forms
5. Asexual reproduction
a. budding
b. regeneration
6. Sexual reproduction
a. mostly dioecious

42. Polymorphism
Dimorphic
Free Swimming Medusa
Fixed Polyp

43. Obelia – polymorphic
life cycle

44. Colonial hydrozoan

45. Class Scyphozoa – “cup animal”
A. genus Aurelia – common
jellyfish
B. Thick mesoglea
C. Tentacles can be up to 70 m
D. Dioecious, polymorphic life
cycle

46. Dimorphic Life Cycle and
Reproductive Modes
Asexual
Budding
 Medusa buds
 Polyp buds
Sexual
Gonadal tissue
Gametes
Fertilization,
embryogenesis
Planula larvae

48. Jelly Fish: Sting scars

50. THE FLAT WORMS

51. General Characteristics
• They exhibit bilateral symmetry: anterior and
posterior ends are different; so are the dorsal
(top) and ventral (bottom) surfaces
•The platyhelminths also exhibit some degree of
cephalization Commonly referred to as the
'flatworms' because their bodies are
dorsoventrally flattened.
•They are acoelomates
•This phylum (and all remaining phyla) possess
3 germ layers (=triploblastic)
•The mesoderm (third germ layer) gives rise to
muscles, various organ systems, and the
parenchyma, a form of solid tissue containing
cells and fibers

52. Outer Body Covering
• The body of some platyhelminthes (e.g.,
turbellarians) is covered by a ciliated
epidermis
• Epidermal cells contain rod-shaped
structures called rhabdites that when
released into the surrounding water,
expand and form a protective mucous
coat around the animal
• The outer body covering of other
platyhelminthes (e.g., parasitic forms) is a
non-ciliated tegument
• The tegument is referred to as a
syncytial epithelium

53. Organ Systems of the Platyhelminthes
Digestive System
• Some of the flatworms possess a digestive system, with a mouth, pharynx, and a
branching intestine from which the nutrients are absorbed
• The intestine, with only one opening, is a blind system

54. Excretory System (osmoregulation)
• A network of water collecting tubules adjacent to flame cells or a
protonephridia
• When cilia beat they move water into the tubules and out the body through
pores called nephridiopores

55. Taxonomic Summary
Phylum
Platyhelminthes
(Flatworms)
Class Turbellaria
Class Cestoda
Class Trematoda
Class Monogeneans
Phylum Platyhelminthes 55

56. Cestoda
The Tapeworms
Endoparasites
Body consists of proglottids and scolex
Proglottids snapshots of development
Scolex has structures for attachment
(Hooks, suckers and rostellum)
No digestive system

58. Class Cestoda
General Morphology
• Nonciliated tegument composed of glycoprotein
• The anterior region is called a scolex; often armed with suckers and hooks
• Extending from the neck is a
series of proglottids; contain the
sex organs and eggs; no digestive
system
• Mature eggs released through an
opening in the proglottid or leave
the host when the proglottids are
separated from the main body of the
worm.

59. Taenia scolex

61. TaeniaEntire – can get to 30+ feet long

63. Trematoda :The Flukes
Endoparasites
Cuticle covering body
Oral sucker surrounds mouth
Ventral sucker used for attachment
Complex life cycles

64. Fasciola hepatica
Fasciola hepatica, also known as the common
liver fluke or sheep liver fluke.
Is a parasitic flatworm of the class Trematoda,
phylum Platyhelminthes that infects liver of
various mammals, including humans.
The disease caused by the fluke is called
fascioliasis (also known as fasciolosis).
 F. hepatica is world-wide distributed and causes
great economic losses in sheep and cattle.
64

65. Fasciola hepatica
Fasciola hepatica

66. Trematoda Lifecycle
The lifecycle
is complex
with up to 4
different
hosts and
several larval
types
Phylum Platyhelminthes 66

67. 67

68. Sheep liver infected with Fasciola hepatica

69. HIGHLIGHTS OF PRESENTATION
• Helpful in understanding the trend of
evolution.
• For better understanding the living
conditions and behaviour of
animals,specially Jellyfish,Taenia and
Fasciola.
• Their economic status.

70. Dr Sameer Mishra