Transcript Sponges, Cnidarians, and Worms

Sponges, Cnidarians, and Worms
Table of Contents
What Is an Animal?
Animal Symmetry
Sponges and Cnidarians
Worms
Sponges, Cnidarians, and Worms
The Animal Kingdom
Chapter 1 Sponges,
Cnidarians and Worms
Sponges, Cnidarians, and Worms - What Is an Animal?
The Animal Kingdom
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the animal kingdom.
Sponges, Cnidarians, and Worms - What Is an Animal?
Animal Characteristics
Animals are many-celled, eukaryotic
organisms that must find and digest food.
Most can move from place to place.
Sponges, Cnidarians, and Worms - What Is an Animal?
Structure of Animals
The cells of most animals are
organized into higher levels of
structure, including tissues,
organs, and systems.
Sponges, Cnidarians, and Worms - What Is an Animal?
Animal Symmetry
All animals have body symmetry.
Symmetry is the balanced arrangement of body
parts.
Three types:
Bilateral Symmetry —just one line that divides an
animal into two halves that are mirror images.
Radial Symmetry —many lines that pass through
a central point: like spokes on a wheel.
Asymmetrical —no symmetry
Sponges, Cnidarians, and Worms - What Is an Animal?
Animal Symmetry
Bilateral
Radial
Asymmetrical
Sponges, Cnidarians, and Worms - What Is an Animal?
Animal Classification
There are 9 animal phyla:
Phylum Porifera —sponges
Phylum Cnidaria —jellyfish, corals, sea
anemones
Phylum Platyhelminthes —flatworms
Phylum Nematoda —roundworms
Phylum Annelida —segmented worms
Sponges, Cnidarians, and Worms - What Is an Animal?
Animal Classification
Phylum Mollusca —snails, clams,
octopus, squid
Phylum Echinodermata —starfish,
sea urchin
Phylum Arthropoda —insects, crabs,
spiders
Phylum Chordata —vertebrates
Sponges, Cnidarians, and Worms - What Is an Animal?
This branching tree shows how the major
animal groups
are related.
Sponges, Cnidarians, and Worms - What Is an Animal?
Vertebrates and Invertebrates
The first eight phyla in
the animal kingdom are
invertebrates—animals
without backbones.
95% of all animals are
invertebrates.
Sponges, Cnidarians, and Worms - What Is an Animal?
Invertebrates
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Sponges, Cnidarians, and Worms - What Is an Animal?
The chordate phylum
represents the only
group of vertebrates—
animals with a
backbone and inside
skeleton
(endoskeleton).
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Phylum Porifera: Sponges
Characteristics:
Simplest animals.
Porifera means “porebearer” in Latin.
Bodies covered with
pores and are made of
different types of cells
but no tissues.
Sponges don’t wear
square pants!!!!
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Phylum Porifera: Sponges
Over 5000 species of all shapes and colors.
All live in water—mostly salt water.
Asymmetrical—no definite shape.
Evolved over 600 million years ago.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Body structure
Hollow, sac-like body with a large
opening at the top called an osculum
and many small openings on the side
called pores.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Sponges are filter-feeders
Water enters through the pores and
leaves through the osculum.
Collar cells filter and digest bacteria,
algae and protists.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Structure of a Sponge Activity
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access Active Art about the structure of a sponge.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Phylum Porifera: Sponges
Sponges reproduce in two ways:
Asexually —budding or regeneration
Sexually —produce sperm and egg
cells.
Sponges are hermaphrodites
(produce both sperm and egg cells):
However, they cannot fertilize their
own eggs.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Phylum Porifera: Sponges
Sperm cells from one sponge enter
another and are taken to the egg
cells. A fertilized egg develops into
a free-swimming larva. The larva
attaches to a rock and becomes an
adult sponge.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
The sexual reproduction of sponges
involves a larval stage that moves. Adult
sponges stay in one place.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Phylum Cnidaria: Jellyfish, Corals, Sea
Anemones and Hydra
Characteristics:
Tentacles with stinging cells called,
cnidocysts.
“Cnidos” is Greek for “stinging nettle”.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Over 9,000 species ranging in size
from microscopic to 70m long.
Live in water—mostly salt water.
Radial symmetry.
Bodies have tissues but no organs.
Evolved 600 million years ago.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
The stinging cells (cnidocysts) come
equipped with harpoon-like stingers called
nematocysts.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
The stings of some
jellyfish can be quite
painful, causing
reactions ranging
from a mild rash to
death.
The Australian Box
Jelly is the most
poisonous—killing
victims in under 5
min.
Wounds from the
sting of a box jelly
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Australian Box Jellyfish
Close-up showing eye spot
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Cnidarians come in two shapes:
Polyp—vase-shaped, sessile
cnidarians.
Medusa—umbrella-shaped mobile
cnidarians.
Medusa
Polyp
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Cnidarians
Cnidarians have two basic body plans, the
vase-shaped polyp and the bowl-shaped
medusa.
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Examples of Cnidarians:
Jellyfish —live as both a polyp and medusa
(mostly as a free-swimming medusa).
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Reproduction in Jellyfish
Sperm and egg cells are released into the
water where they unite.
Fertilized eggs develop into a larva that
attaches to a rock.
A larva becomes a sessile planula, which
grows a mouth and tentacles and is now
called a polyp.
The polyp divides into a stack of saucer-like
structures that swim away as adult medusas.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Cnidarians
The life cycle
of a moon jelly
has both a
polyp and a
medusa
stage.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Hydra —small polyps attached to rocks in
freshwater streams and ponds. Can
reproduce asexually by budding.
Adult hydra with bud
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Corals and Sea Anemones —polyps that
live attached to rocks on the ocean floor or
in large colonies called reefs.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Coral Reefs
Coral Reefs
A coral reef is made of
billions of skeletons of
dead corals that are
covered by a layer of
living coral polyps.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Largest = Great Barrier
Reef of Australia (1200
miles long and 48 miles
wide).
Very diverse habitats
(home to 35,000 to 60,000
different species).
All are located between 300
N and 300 S latitude.
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Types of Coral Reefs
Fringing reef—forms close to the shoreline of
islands or continents.
Barrier reef—located farther out. Separated
from land by a lagoon.
Atoll—formed when fringing reef shrinks—
sometimes at the top of a mid-ocean volcano.
Fringing reef
Barrier reef
Atoll
Sponges, Cnidarians, and Worms - Sponges and Cnidarians
Importance of the Coral Reef:
Help protect the shoreline from storms.
Important source of food and shelter
for many other marine organisms.
Easily damaged by pollution, careless
boaters and careless divers.
Reef balls are used to repair damage
reefs.
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Phylum Platyhelminthes:
Flatworms
All have flat, legless bodies with no
internal body cavity.
Some are free-living, some are
parasites.
All have bilateral symmetry.
Three examples: tapeworms,
flukes, and turbellarians.
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Tapeworms —parasitic flatworms
that live in the intestines of a host
animal.
Feed on the host’s digested
food.
Size: 6-12 meters.
Humans can catch a
tapeworm from eating
undercooked beef, pork or
fish.
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Flukes —parasitic flatworms that live inside
the bodies of humans and animals.
Shistosoma is a blood fluke found
in polluted water. It kills 200 million
people a year by blocking arteries of
infected people.
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Turbellarians —free-living flatworms.
Most live in the ocean.
Ocean turbellarian
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The planarian is a fresh-water
turbellarian. It swims using cilia and
can reproduce both asexually, by
regeneration, and sexually. It has two
eyespots on the anterior end that
respond to light.
Sponges, Cnidarians, and Worms - Worms
Phylum Nematoda: Roundworms
Long, tapered bodies with a true body cavity
between their layers of tissue.
All have a complete, one-way digestive
tract.
Most are free-living, however, some are
serious human parasites.
Sponges, Cnidarians, and Worms - Worms
Parasitic roundworms
include:
Hookworms—caught
by walking barefoot
in tropical soil. Larva
travel to the intestines,
lungs or brain.
Hookworm
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Trichina—caught by
eating undercooked
pork. Causes
muscle pain and
breathing problems.
Trichina
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Ascaris—caught by eating ascaris
eggs found in contaminated food.
Worms live in intestines of host.
Common in puppies and kittens.
Ascaris
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Pinworms—caught by ingesting
pinworm eggs. Causes an “itchy
bum”. It is the most common human
intestinal parasite.
Pinworm
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Heartworm—
roundworm parasite
of dogs only.
Transmitted by
mosquitoes.
Easily prevented
but difficult to treat
once diagnosed.
Heartworm
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Phylum Annelida: Segmented
Worms
Tube-shaped bodies with
segments.
“Annelid” means “little
rings”.
Some are free-living in soil,
saltwater or freshwater.
Others are parasites.
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Three classes: marine worms,
earthworms, and leeches.
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Segmented Worms
Earthworms and other segmented worms
have bodies made up of many linked
sections called segments.
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Marine Worms —over 6,000 species of
segmented worms that live in the ocean.
Move using parapodia
Include: giant tube worms, sand worms,
bristle worms, and feather-dusters.
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Leeches —external parasites that feed
on the blood of a host.
Formerly used in blood-letting.
Currently used in microsurgery.
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Earthworms —free-living annelids found in
the soil.
Have complete body systems:
circulatory, respiratory, digestive,
nervous, and reproductive.