2. OBJECTIVES
To familiarize and identify the different
sponges specimens.
To classify the different sponges
according to classes, body types and
chemical components of spicules.
To identify the different spicules in the
sponges.
3. Different Types of Poriferans
Class Calcarea
Class Hexactinellida
Class Demospongiae
4. Class Calcarea
Calcareous sponges (Class Calcarea) have
spicules composed of calcium carbonate.
Small, usually vase shaped.
Asconoid, syconoid, or leuconoid in structure.
5. Class Hexactinellida
Glass sponges (Class Hexactinellida) are mostly
deep sea forms.
Spicules are six-rayed and made of silica.
Hexactinellids lack a pinacoderm or gelatinous
mesohyll.
Chambers appear to correspond to both syconoid and
leuconoid types.
6. Class Hexactinellida
Some advocate placing
hexactinellids in a subphylum
separate from other sponges.
Trabecular reticulum made of a
fusion of archaeocyte
pseudopodia - forms the
chambers opening to spongocoel.
Trabecular reticulum is largest
continuous syncytial tissue
known in Metazoa.
Choanoblasts are associated with
flagellated chambers.
Collar bodies do not participate in
phagocytosis – this is the function
of the primary and secondary
reticula.
7. Class Demospongiae
Class Demospongiae
contains most of the
sponge species.
Spicules are siliceous,
but not six-rayed.
Spicules may be bound
together by spongin, or
absent.
All leuconoid, mostly
marine.
9. What are the bases of classifying
sponges?
Base on the shape and chemical
composition of the sponges
10. Give the ecological importance of
sponges.
Filter feeders
Algae are attached
Contains toxins that are of medical
importance
11. Phylum CNIDARIA
Cnidaria (Gr knide, nettle + L. aria; like
or connected with
With more than 9,000 species
Cnidocytes = which contain stinging
organelles (cnidae)
Cnidae come in several types including
the common nematocysts
Nematocysts are used only by
cnidarians
13. OBJECTIVES
To familiarize and identify the different
representatives of Cnidarians
To identify the parts of Cnidarians and
know its function.
To identify the corals based on their
morphological characteristics.
14. CNIDARIANS
BODY PLANS:
Have two body forms MEDUSA &
POLYPS
Have Radial Symmetry
Known for Cnidocytes – contain
stinging cells such as nematocyst
REPRODUCTION: Reproduce
Sexually & Asexually
Free-swimming larva -
planula
15. Classification of Cnidaria
Class Hydrozoa
Hydra
Obelia
Goneonemus
Class Scyphozoa
Jellyfishes
Class Anthozoa
Sea anemone
Stony corals
Class Cubozoa
The basis of classification is the adult forms whether polyp o
16. What are the bases of classifying
cnidarians?
Based on the composition of the
hydranths covering e.g. chitinous),
accumulation of calcium carbonate and
number of pinnate tentacles
17. Give the ecological importance
of Cnidarians
Hydras as food for mollusc and
flatworms
Live as commensals on shells and other
surface of host (sea anemones and
certain hydroids)
Economic value of reef
Reef provide substantial amounts of food for
human (fish and other animals associated
with reefs
18. Give the ecological importance
of Cnidarians
Includes:
branching, plantlike hydroids
Flowerlike sea anemones
Architects of the ocean floor- gorgonian
corals (sea whips, sea fans, etc)
Stony corals –whose thousand of years
of calcareous housebuilding great
reefs and coral islands.
19. Class Hydrozoa
Fresh water members of this class live
singly, but the marine forms live singly or
form polymorphic colony.
Though only polyp or medusa is found
but sometimes both polyp or medusa
may be found in the same animal.
Gastrovascular cavity is directly
connected with mouth.
20. Class Hydrozoa
Alternation of generation is found in the
life cycle.
Ciliated planula larva is found.
No stomodeum, velum present in
medusa.
Radial canals in medusa are not
branched.
Gametes develop from ectoderm.
22. Kingdom Animalia (animals)
Eumetazoa (metazoans)
Phylum Cnidaria (cnidarians)
Class Hydrozoa (hydralike animals, hydroids,
and hydrozoans)
Order Hydroida (medusae)
Suborder Hydrida
Family Hydridae
Genus Hydra
Species Hydra utahensis
23. Hydra Class Hydrozoa
Order Hydroida
Suborder Anthomedusae
Freshwater species
Hydranths lack a
chitinous covering
With no medusa stage
Length up to 25-30 mm
28. Obelia
Colonial or solitary
Colonial marine hydroid
that forms a minute
plantlike growth on rocks,
pilings, and other
substrates
Hydranths with chitinous
covering
32. Anthozoans include
corals, sea anemones,
sea pens, and sea
pansies.
These animals are either
solitary or colonial polyps
that live attached to a
substrate (surface).
Of the 6,000 known
anthozoan species, corals
comprise about 2,500
species.
33. Class Anthozoa
Sea anemones and corals have polyps
and no medusae
Corals are colonial and secrete calcium
carbonate skeletons. Coral reefs are the
accumulation of these skeletons.
34. Class Anthozoa
The Class Anthozoa is further divided into three subclasses:
Octocorallia, Zoantharia, and Tabulata (extinct colonial corals).
•Subclass Octocorallia. Polyps are characterized by having eight
pinnate (side- branching) tentacles. Octocorallians include
gorgonian corals, sea pens, sea pansies, organ- pipe corals, and
soft corals (order Alcyonacea). Most are colonial.
•Subclass Zoantharia. Polyps are characterized by having
tentacles in multiples of six. Zoantharian tentacles are rarely
pinnate. Black corals and reef-building corals (order Scleractinia)
are members of this subclass. Reef-building corals are also
known as "hard corals" or "stony corals". Zoantharians may be
either solitary or colonial.
36. Classification:
Kingdom Animalia (animals)
Phylum Coelenterata (corals, jellyfish, sea anemones
hydroids)
Class Anthozoa meaning "flower-like animals"
(corals and sea anemones)
Order Actiniaria.
Diadumene dia
37. Stony Corals
Class Anthozoa
Subclass Zoantharia (Hexacorallia)
Order Scleractinia
Genus Meandrina (Brain coral)
Genus Astrangia (Eyed coral)
Genus Fungia (Mushroom coral)
Genus Acropora (Staghorn, elkhorn, Antler coral)
Genus Porites (reef coral)
Genus Oculina
38.
39.
40.
41.
42.
43.
44.
45.
46. Class Scyphozoa
This Class contains the larger jellyfishes,
with some reaching two metres across the
bell and with tentacles 30 metres long.
They are mainly marine and free floating,
though they can "swim" by pulsations of the
bell. In this Class the polyp stage is either
reduced or absent. There are around 215
species.
48. Aurelia sp.
Aurelia sp. is a typical
example
The lappets come in pairs,
and between them is a
sense organ called a
rhopalium containing a
statocysts to give the
animal information on its
equilibrium and orientation,
sensory pits, and, in some
species, ocelli (simple eyes).
http://cas.bellarmine.edu/tietjen/AnimalDiversity
/Lab4%20Porifera%20and%20Cnidaria.htm
Aurelia rhopallium,
a multifunction sensory organ
49. Aurelia sp.
The oral arms capture prey.
The tentacles are armed
with nematocysts (see
illustration on the right), as
is the entire body surface.
Aurelia sp. has relatively
short tentacles, and feeds
on plankton. The plankton is
passed to the mouth by
cilia.
http://cas.bellarmine.edu/tietjen/AnimalDiversity
/Lab4%20Porifera%20and%20Cnidaria.htm
51. Sea Nettle scientific
classification:
Kingdom: Animalia
Phylum: Cnidaria
Class: Scyphozoa
Order: Semaeostomeae
Family: Pelagiidae
Genus: Chrysaora
Species: Chrysaora
fuscescens
Pacific Sea Nettle (Chrysaora fuscescens), Montery BayAquarium
Dec 2009, Photo by Mark Leavitt
52. Class Cubozoa
The cubozoan body is shaped like a square bell,
with the mouth suspended inside it on a tube (the
manubrium) that leads upward to the stomach,
which is inside the top part of the bell.
Box jellyfish have eyes that are surprisingly
complex, including regions with lenses, corneas,
and retinas; however, box jellyfish do not have a
brain, so how the images are interpreted remains
unknown.
possess stinging cells that can fire a barb and
transfer venom (Waggoner and Collins 2000).
54. Activity: ½ x.w. paper
Draw the flowchart taxonomic
classification of the classes of
Cnidarians
55. Acoelomate Bilateral Animals
The term worm is loosely employed in
biology and is applied to very different
animals including the segmented worms
(Annelids), roundworms
(pseudocolomates and a variety of
acoelomate bilateral animals.
56. Acoelomate Bilateral Animals
There are three phyla of acoelomate
bilateral animals:
Platyhelminthes: flatworms
Nemertea: ribbon worms
Gnathostomulida: jawed worms
57. Acoelomate Bilateral Animals
By far the most important in diversity and
economic importance is the phylum
Platyhelminthes, which includes a
variety of parasitic forms such as the
flukes and tapeworms.
58. Phylum Platyhelminthes
Members of the Platyhelminthes typically have
dorsoventrally flattened bodies that are usually
slender and leaflike or ribbonlike.
There are four classes in the Platyhelminthes.
The Turbellaria are free living whereas as
members of the Monogenea, Trematoda and
Cestoda are parasitic.
59. Classification of Platyhelminthes
There are four classes in the
Platyhelminthes:
Class Turbellaria: free-living flatworms.
Class Turbellaria: endoparasitic flukes
Class Monogenea: parasitic flukes that are
mainly ectoparasites
Class Cestoda: tapeworms
60. Class Turbellaria
Class Turbellaria contains about 3000 species.
There is considerable debate about the
classification of the class and it is likely that
the class is not monophyletic.
Most species are marine and benthic.
However, some are also found in fresh water
as well as in moist temperate and tropical
terrestrial habitats.
63. Class Turbellaria
Most Turbellarians are predators of
invertebrates smaller than themselves. Other
species are herbivores or scavengers.
Turbellarians move by swimming, creeping or
crawling. They combine muscular
contractions with ciliary movement to move.
64. Class Trematoda
There are about 9000 species of
trematodes all of which are parasitic.
Most parasitize vertebrates.
Adaptations for parasitism include
suckers and hooks for attachment,
glands to produce cyst material and
increased reproductive capacity.
66. Class Trematoda
Structurally trematodes are similar to
turbellarians having a well developed
digestive system and similar nervous,
excretory, and reproductive systems.
However, a major difference is the
tegument.
67. Digenean Trematodes
There are three subclasses of
Trematodes, but two are small, poorly
studied groups.
The third group, the Digenea, however is
a large group of major medical and
economic importance.
68. Digenean trematodes
The flukes have a complex life cycle in
which a snail is the first (or intermediate)
host and a vertebrate the final (or
definitive host).
The definitive host is one in which the
fluke reproduces sexually.
69. Digenean trematodes
In some species there may be 2 or 3
intermediate hosts before the definitive
host is reached.
Trematodes inhabit a variety of sites in
their hosts including the digestive tract,
respiratory tract, circulatory system,
urinary tract, and reproductive tract.
71. Clonorchis liver fluke
Clonorchis is the most important liver fluke to infect
humans. Common in much of Asia (including China,
Japan and southern Asia).
Adult flukes live in the bile passages and shelled
miricidia pass out in feces. The miricidia enter snails
eventually leave the snails as cercariae and find a fish
where they encyst.
If fish is eaten raw or poorly cooked the person
becomes infected
73. Schistosomiasis
Schsitosomiasis is an infection with
blood flukes and is one of the most
important major infectious diseases on
the planet.
More then 200 million people are
infected worldwide with these flukes
which they acquire swimming or walking
in water in which the intermediate snail
host lives
75. Schistosomiasis
When a schistosome cercaria swims it takes
care to avoid UV light which can damage it,
but is very sensitive to the scent of humans.
When it senses molecules from human skin it
swims rapidly and jerks around looking for the
person. When it makes contact it releases
chemicals that soften the skin and burrows in
shedding its tail at the same time.
77. Class Monogenea
The monogenetic flukes were previously
classified as on order of the Trematoda, but
recent work suggests they are more closely
related to cestodes (tapeworms).
Monogeneans are typically external parasites
of fish that clamp onto the gills using a hooked
organ called an opisthaptor. Some also
parasitize frogs and turtles.
79. Class Monogenea
Unlike the trematodes Monogeneans
have only a single host.
The egg hatches into a ciliated larva
which seeks out its host in the water.
80. Class Cestoda (tapeworms)
Tapeworms are parasites of the
vertebrate digestive tract and about
4000 species of are known.
Almost all tapeworms require at least
two hosts with the definitive host being a
vertebrate although intermediate hosts
can be invertebrates.
81. Class Cestoda
Members of the Class Cestoda (tapeworms)
are quite different in appearance from the
other members of the Platyhelminthes.
They have long, flat, tape-like bodies
composed of a scolex for attaching to their
host and a chain of many reproductive units or
proglottids called a strobila. New proglottids
form behind the scolex and the strobila may
become extremely long.
83. Tapeworm scolex
The scolex is equipped with a combination ofThe scolex is equipped with a combination of
suckers and hooks that enable it to grip onto itssuckers and hooks that enable it to grip onto its
host’s intestines.host’s intestines.
Hooks
Suckers
85. Human tapeworms
Humans are definitive hosts to several
tapeworms including the beef tapeworm
Taenia saginata, pork tapeworm T.
solium, and fish tapeworm
Diphyllobothrium latum.
89. Phylum Nematoda
From the Greek Nema for Thread and
Eidos for form.
only about 80 000 species have been
described
Nematodes live in a vast variety of
habitats,
ecologically they can be divided into free
living forms
and parasitic forms.
90. Characteristics of Nematoda
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.
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.
101. Phylum Annelida
This phylum is divided into three classes:
Oligochaeta: Earthworms - Most
earthworms and their equals are
inhabitants of damp soil and fresh waters.
Hirudinea: Leeches - The leeches are
found mainly in fresh water or on moist
ground.
Polychaeta: Bristle-worms - The marine
worms are found chiefly in close vicinity of
the shore.
101
105. Adult (sexually mature)
earthworms have a
distinct swelling called a
clitellum.
Adult (sexually mature)
earthworms have a
distinct swelling called a
clitellum.
• located about one-third of
the way down the
earthworm
• often white or orange in
colour
• It produces most of the
material secreted to form
earthworm cocoons.
• Forms a band that can be
flared, non-flared, saddle-
shaped, or annular. It is
generally found between
segments 26 and 33.
105
106. The shorter region
to one side of the
clitellum is the
anterior or head-
end of the animal
This end of the
worm is usually
more pointed than
the posterior end of
the animal.posterior
or
tail end
anterior
or
head-
end
106
The periproct is the last
segment of an earthworm.
109. Setae
• Each segment, except the first and last, have
tiny bristle-like structures called setae.
These structures help the earthworm to
move and act to sense the environment.
109
119. Reference:
Hickman Jr. C.P. and et al., 2007. Animal
Diversity 4th
edition. Boston: McGrawHill
http://www.naturewatch.ca/english/wormwat
ch/resources/anatomy.html
119
Editor's Notes
The male is easily recognized by its conspicuous copulatory bursa, an expanded posterior portion of the worm used for grasping the female during mating.
