Kingdom Animalia,
Porifera& Cnidarians
How Are Animals Classified?

All are Multicellular Eukaryotes

All animals are consumers

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No producers or decomposers
Scientists generally look at several things:
1.
Absence or presence of backbone
2.
Symmetry
3.
Presence of organ systems
4.
Embryonic Development
#1 Presence or Absence of
Backbone.

The backbone is called the vertebrae
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Invertebrates lack vertebrae
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Vertebrates have a backbone
#2: Symmetry
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If an organism has no symmetry, it is asymmetrical
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Radial symmetry-Organism is arranged in a circle around a central
point
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Bilateral symmetry-2 sides that are mirror-images
#3: Presence of Organ Systems
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Some organisms are very simple
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Sponges do not have tissues or organs

Insects have some organ systems, but humans have more
No lungs!
Lungs!
#4: Embryonic Development
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Beyond level we are at
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Deals with what portion of the “tube” (mouth to anus) of the
body forms first as the organism develops from fertilization

Most animals form the mouth first

Vertebrates and sea stars form the anus first
Invertebrates
Animal Phyla We Will Study:

Porifera (Sponges)

Cnidarians (Jellyfish, coral, Portuguese Man-Of-War

Mollusca (Mollusks)
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Annelida (Worms)
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Arthropodq (Insects, Arachnids, Millipedes and NOT their creepy cousins)
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Tardigrada (Coolest organisms ever!)
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Echinodermata (Sea Stars)

Chordata (Vertibrates)
Phylum Porifera

The sponges

Yes, they are considered animals

Not plants

Invertebrates
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Usually asymmetrical

Lack tissues, organs, and organ systems

Sessile (does not move) except in larval form

Filter feeders

Collect tiny organisms and debris that flow through it

https://www.youtube.com/watch?v=RmPTM965-1c
Porifera Reproduction

Can be sexual or asexual

Sexual

Sponges are hermaphroditic as adults

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One sponge will release millions of sperm in the water

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It then lands on the ground nearby, and never moves again
Asexual
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Budding

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A “baby” sponge grows on the parent sponge, breaks off, then grows where it landed
Regeneration

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They reach another sponge and fertilize the egg
The “baby” (called a larva) grows a flagella and swims out of the parent sponge


Can produce both sperm and eggs
A part of the sponge breaks off and grows into a new sponge
https://www.youtube.com/watch?v=xj-C52c9qlI (audio quality not good; visuals are)
Phylum Cnidaria
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Invertibrates
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Can be radially or bilaterally symmetrical
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Jellyfish, hydras, Portuguese Man-of-War, and coral

Get their names from cnidocytes (stinging cells)

Have a Digestive system


No nervous system because no brain
Most live in salt water, few in freshwater
Two Body Forms in Cnidarians
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Cnidarians come in 2 different body types


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Some transition between these forms in their lifetime
Polyp form
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Sessile form (does not move)
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Radially symmetrical
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Tentacles on top
Medusa form
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Mobile (moves)

Radially or bilaterally symmetrical

Tentacles on bottom
Reproduction

Can be sexual or asexual
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Polyps can reproduce by budding

Sexual reproduction is similar to sponges

Release millions of sperm into water
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Also release eggs into water
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When the egg meets a sperm, it grows a polyp in that place
Medusa forms start from polyp form
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They break free as they develop, and become free-swimming
Jellyfish
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https://www.youtube.com/watch?v=-UZxEo8k894
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Come in many varieties

Can be bioluminescent
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Stings are painful, and can be deadly

One of the most venomous organisms on Earth is the Box Jellyfish

https://www.youtube.com/watch?v=-2KR8LypESI
Portuguese Man-Of-War
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Interestingly, not a single organism, but a floating colony of tiny organisms

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Tentacles can be 30 meters (nearly 100 feet) long
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Each of these organisms relies on the others, and cannot survive independently
Stings are very painful, but usually not deadly
https://www.youtube.com/watch?v=bPbQs4Zc85k
Coral

Sessile cnidarians

Form colonies

Coral reef

Have tiny tentacles around their “mouth”

https://www.youtube.com/watch?v=47vGQh4BGKM