Transcript Muscular System - walker2013

Porifera and Cnidaria
Chapter 26.1 and 26.2
Animal Classification
Invertebrates
.Sponges
Cnidarians
Worms
Mollusks
Arthropods
Echinoderms
Phylum Porifera
Animals
(cold-blooded)
Fishes
Amphibians
Reptiles
Endotherms
Birds
Mammals
Ectotherms
Vertebrates
(warm-blooded)
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Kingdom: Animalia
Phylum: Porifera
More than 5000 species have been identified
Most are found in marine biomes (salt water)
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Around 150 species are found in freshwater
Characteristics
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Asymmetrical
The first multicellular
organism
Sponges are consisted
of groups of cells
No respiratory,
excretory or nervous
systems
Characteristics
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Filter feeders
Some species can be
torn apart and
reassemble itself
Anatomy of the Sponge
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Pore cell – allows water
carrying food and
oxygen into the sponge
Epithelial-like cells –
control what goes in the
sponge by closing
pores
Osculum – Water and
waste are expelled
through this structure
Pore cell
Collar cell
Epithelial-like
cells
Anatomy of the Sponge
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Collar cell – has a
flagellum that moves
water into the cell
Spicules – small,
needlelike structures
that give sponges
support
Ameobocytes – carry
nutrients, aid in
reproduction, and help
produce spicules
Collar cell
Anatomy of the Sponge
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Collar cell
Food is broken down at
the amebocyte
Asexual Reproduction in Sponges
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Budding – an external
growth forms on a
sponge
Sponge colonies are
formed by budding
Fragmentation – a part
of a sponge breaks off
and grows into a new
sponge
Sexual Reproduction of Sponges
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Some sponges have one sex
Most sponges are hermaphrodites – animals
that can produce both sperm and eggs
Fertilization can be external or internal
sperm
Fertilizes to
form larva
Larva
attaches to a
surface
Sponge releases sperm
egg
Sponge releases egg
A new
sponge
develops
Support and Defense Systems in Sponges
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Spicules gives sponges
support
Some sponges contain
chemicals that are toxic
to fishes
Animal Classification
Invertebrates
Sponges
Cnidarians
Worms
Mollusks
Arthropods
Enchinoderms
Phylum Cnidaria
Jellyfish
Hydra
Coral
Sea anemone
Animals
(cold-blooded)
Fishes
Amphibians
Reptiles
Endotherms
Birds
Mammals
Ectotherms
Vertebrates
(warm-blooded)
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Kingdom: Animalia
Phylum: Cnidaria
Cnidarians consist of 9000 species of
jellyfishes, corals, sea anemones, and hydras
Most cnidarians are found in marine biomes
Sea anemone
Corals
Hydra
Characteristics
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Radial symmetrical
One body opening
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The mouth is also the anus
Two Body Forms
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Polyps
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Familiar body form of
hydras
Sessile
Tentacles and
mouth/anus face up
Reproduces asexually
by budding
Two Body Forms
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Medusa
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Familiar body form of
jellyfishes
Mobile
Tentacles and
mouth/anus hang down
Reproduces sexually
using sperm and eggs
Reproduction in Cnidarians
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Cnidarians can reproduce sexually and
asexually
Sexual Reproduction
Blastula
Larva
Medusa
breaks away
Asexual
Reproduction
Reproduce by
budding
Polyp
Attach
to
surface
Digestion in Cnidarians
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Cnidocyte – stinging
cells located at the tips
of the tentacles
Digestion in Cnidarians
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Nematocyst – a small
barbed harpoon used
for defense and to
spear prey
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The nematocysts
discharge when prey
touches the tentacles
Nematocysts inject prey
smooth (like a knife) and
flare out (like barb wire)
Digestion in Cnidarians
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Gastrovascular cavity – digestive enzymes
are released over captured prey in this space
Undigested materials are ejected out of the
mouth
Nervous System in Cnidarians
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Nerve net – conducts impulses to and from
all parts of the body
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A simple nervous system