Invertebrate Animals by Phylum
Porifera
Cnidaria
Platyhelminthes
Nematoda
Mollusca
Annelida
Arthropoda
What’s a PHYLUM?
• Phylum: a taxonomic grouping of similar
classes of organisms
• Translation: a “phylum” is a GROUP of
organisms who have a lot in common
• Phyla are big, huge CLADES, just below
KINGDOMS in size and just above CLASSES in
size
What’s an INVERTEBRATE?
• Definition: an animal without a
backbone.
• None of the animals so far have had
backbones, but we’re not done yet!
On to the Phyla!
•
•
•
•
•
•
•
Porifera
Cnidaria
Platyhelminthes
Nematoda
Mollusca
Annelida
Arthropoda
 Already covered in detail.
Today’s Focus. But what do
you already know?
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
• The first animals: SPONGES!
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
• The first animals: SPONGES!
• Asymmetrical body plan
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
• The first animals: SPONGES!
• Asymmetrical body plan
• Sessile adults, mobile “babies”
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
•
•
•
•
The first animals: SPONGES!
Asymmetrical body plan
Sessile adults, mobile “babies”
Filter-feed to eat
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
•
•
•
•
•
The first animals: SPONGES!
Asymmetrical body plan
Sessile adults, mobile “babies”
Filter-feed to eat
Reproduce Sexually: pump sperm into water
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
•
•
•
•
•
•
The first animals: SPONGES!
Asymmetrical body plan
Sessile adults, mobile “babies”
Filter-feed to eat
Reproduce Sexually: pump sperm into water
Reproduce Asexually: by “budding”
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
•
•
•
•
•
•
Asymmetrical body plan
Sessile adults, mobile “babies”
Filter-feed to eat
Reproduce Sexually: pump sperm into water
Reproduce Asexually: by “budding”
No internal organs; acoelomate
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Porifera
• Asymmetrical body plan
• Sessile adults, mobile “babies”
•
•
•
•
•
•
Filter-feed to eat
Reproduce Sexually: pump sperm into water
Reproduce Asexually: by “budding”
No digestive tract
No internal organs; acoelomate
Key adaptations:
Have all general “animal” traits
• Special:
– held together by collagen, spicules for defense, complete
regeneration!!!!1!
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Cnidaria!
• The First MOVERS: Sea Anemones & Jellyfish!
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Cnidaria
2 radially symmetrical body plans: POLYP and MEDUSA
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Cnidaria
• Sea Anemones & Jellyfish!
• 2 radially symmetrical body plans: POLYP and MEDUSA
• Usually sessile polyps, mobile medusas
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Cnidaria
•
•
•
•
Sea Anemones & Jellyfish!
2 radially symmetrical body plans: POLYP and MEDUSA
Sessile polyps, Mobile medusas
Nutrition: actively capture prey
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Cnidaria
•
•
•
•
•
Sea Anemones & Jellyfish!
2 radially symmetrical body plans: POLYP and MEDUSA
Sessile polyps, Mobile medusas
Actively capture prey
Adults reproduce sexually
and are dioecious
• Moon jelly polyps reproduce
asexually by budding
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Cnidaria
•
•
•
•
Sea Anemones & Jellyfish!
2 radially symmetrical body plans: POLYP and MEDUSA
Sessile polyps, Mobile medusas
Actively capture prey
• Reproduction:
– mostly sexual (dioecious: 2 separate sexes)
– Moon Jelly polyps reproduce asexually (by budding)
PoriferaCnidariaPlatyhelminthesNematodaMolluscaAnnelidaArthropoda
Phylum Cnidaria
• 2 radially symmetrical body plans: POLYP and MEDUSA
• Sessile polyps, Mobile medusas
• Actively capture prey
• Reproduction:
– mostly sexual (dioecious: 2 separate sexes)
– Moon Jelly polyps reproduce asexually (by budding)
• Key adaptations:
– Movement (nerve net, 2 sets of muscles)
– Incomplete Digestive Tract (mouth, stomach, no anus)
– Behavior (capture prey, fight, mate)
• Special:
– Liquid Skeleton, nematocysts, tentacles
Porifera  Cnidaria  Platyhelminthes Nematoda  Mollusca  Annelida  Arthropoda
Phylum Platyhelminthes!
Planarian Flatworms
• Habitat: salt and freshwater
Parasitic Flatworms
• Habitat: inside other animals
Porifera  Cnidaria  Platyhelminthes Nematoda  Mollusca  Annelida  Arthropoda
Phylum Platyhelminthes
Planarian Flatworms
• Habitat: salt and freshwater
• Body plan: bilateral symmetry,
cephalization (has a head)
Parasitic Flatworms
• Habitat: inside other animals
• Body plan: bilateral symmetry,
cephalization (has a head)
Porifera  Cnidaria  Platyhelminthes Nematoda  Mollusca  Annelida  Arthropoda
Phylum Platyhelminthes
Planarian Flatworms
• Habitat: salt and freshwater
• Body plan: bilateral symmetry,
cephalization (has a head)
• Locomotion: ripple to swim
Parasitic Flatworms
• Habitat: inside other animals
• Body plan: bilateral symmetry,
cephalization (has a head)
• Locomotion: sessile inside host
Porifera  Cnidaria  Platyhelminthes Nematoda  Mollusca  Annelida  Arthropoda
Phylum Platyhelminthes
Planarian Flatworms
• Habitat: salt and freshwater
• Body plan: bilateral symmetry,
cephalization (has a head)
• Locomotion: ripple to swim
• Nutrition: hunts for food,
Parasitic Flatworms
• Habitat: inside other animals
• Body plan: bilateral symmetry,
cephalization (has a head)
• Locomotion: sessile inside host
• Nutrition: steals host’s food;
Porifera  Cnidaria  Platyhelminthes Nematoda  Mollusca  Annelida  Arthropoda
Phylum Platyhelminthes
Planarian Flatworms
•
•
•
•
•
Parasitic Flatworms
Habitat: salt and freshwater
• Habitat: inside other animals
Body plan: bilateral symmetry, • Body plan: bilateral symmetry,
cephalization (has a head)
cephalization (has a head)
Locomotion: ripple to swim
• Locomotion: sessile inside host
Nutrition: hunts for food, tube- • Nutrition: steals host’s food;
like “pharynx” for mouth
head is “scolex” with suckers
Reproduction: sexual
• Reproduction: sexual (complex
hermaphroditism, asexual
parasitic life cycle)
regeneration
Porifera  Cnidaria  Platyhelminthes Nematoda  Mollusca  Annelida  Arthropoda
Phylum Platyhelminthes
Planarian Flatworms
Parasitic Flatworms
• Habitat: salt and freshwater
• Body plan: bilateral symmetry,
cephalized
• Locomotion: ripple to swim
• Nutrition: hunts for food, tube-like
“pharynx” for mouth
• sexual hermaphrodites, asexual
regeneration
• Key adaptations:
• Habitat: inside other animals
• Body plan: bilateral symmetry,
cephalized
• Locomotion: sessile inside host
• Nutrition: steals host’s food; head is
a “scolex” with suckers
– bilateral symmetry, arrow-shaped
head, sense organs, ganglia
• Reproduction: sexual (complex
parasitic life cycle)
• Key adaptations:
– bilateral symmetry, arrow-shaped
head, sense organs, ganglia
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Nematoda!
• Common name: ROUNDWORMS
• Body plan: bilateral symmetry, cylindrical
body with tapered ends
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Nematoda
• Locomotion: twitching, flicking motion
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Nematoda
• Nutrition: carnivores, herbivores, and decomposers
Parasitic roundworms
Eat off of host
Free-living roundworms
Eat micro-organisms in soil
PoriferaCnidariaPlatyhelminthesNematodaMolluscaAnnelidaArthropoda
Phylum Nematoda
• Reproduction:
– Sexual; separate males and females; females bigger
PoriferaCnidariaPlatyhelminthesNematodaMolluscaAnnelidaArthropoda
Phylum Nematoda
• Coelom?
– Has some organs, just no COELOM to hold them!
– Psuedocoelomate.
PoriferaCnidariaPlatyhelminthesNematodaMolluscaAnnelidaArthropoda
Phylum Nematoda
• New adaptations
–Complete digestive tract (an anus!)
–Semi-terrestrial
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Mollusca!
• 3 Classes of Mollusks:
– Bivalves
• “two shelled”
• Clams & oysters
– Gastropods
• “stomache foot”
• Snails & slugs
– Cephalopods
• “head foot”
• Octopi, squids, and cuttlefish
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Mollusca
• Body Plan: Bilateral symmetry, soft body with
a hard shell (usually)
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Mollusca
• Nutrition:
– Active hunters
and grazers
– Scrape up
food w/ radula
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Mollusca
• Reproduction:
– Sexual
– Non-hermaphroditic (dioecious)
– Both internal and external fertilization
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Mollusca
• Key adaptations:
–COELOMATE!
–Advanced eyes
–Open circulatory
system
• Special:
–High intelligence, hard shell, beak,
jet propulsion
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Annelida!
• Representative species: earthworms,
leeches, polychaetes
• AKA “Segmented Worms”
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Annelida
• Body Plan:
–Bilaterally symmetrical
–Long, thin, segmented body
• New Adaptations:
–Segmentation
–Closed circulatory system
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Annelida
• Nutrition:
–Some filter-feed
–Some graze on plants
–Some parasites
–Some are vicious predators
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Annelida
• Reproduction:
– All kinds!
• Mostly sexual
– Some hermaphroditic
– Some dioecious
• Some asexual
– Cut in half, have two worms
• Mostly internal fertilization, some external
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Annelida
• New adaptations:
– Closed circulatory system
• More efficient delivery of blood/oxygen
– Segmentation
• allows better movement and sequential parts
• Locomotion:
– Peristaltic movement
– Parapodia
– Setae for traction
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Finally: Phylum Arthropoda
• The conquerors!
• Representatives:
– insects
– arachnids
– crustaceans
Probably more than ten million species.
Whoa.
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Arthropoda
• Body Plan:
– Bilateral symmetry
– Segmented
– Exoskeleton
– Jointed appendages
– Many internal organs
There MUST be a coelom to hold it all in place!
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Arthropoda
• Nutrition: Very diverse!
– Herbivores AND carnivores. . .
– Grazers, hunters, trappers, parasites. . .
• Locomotion: Very diverse!
• Some fly, some swim, some walk or dig
They’re everywhere, eating everything!
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Arthropoda
• Reproduction: Very diverse!
– Mostly dioecious
– Mostly internal fertilization
– Mostly have complex metamorphic life cycles.
• (lay eggs, larvae hatch, larvae grow and metamorphose
into adults)
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phylum Arthropoda
• New adaptations:
– Jointed appendages
• used for SO MANY THINGS
– Exoskeleton
• Protection, anchor muscles, keeps water in body
– Respiratory system
• For being totally terrestrial!
– Terrestrial
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phyla: where we’ve been.
Porifera - Sponges
Cnidaria - Jellyfish, Sea Anemones, Hydras
Platyhelminthes - Flatworms
Nematoda - Roundworms
Mollusca - Bivalves, Gastropods, Cephalopods
Annelida - Segmented Worms
Arthropoda - Insects, Arachnids, Crustaceans
Porifera  Cnidaria  Platyhelminthes  Nematoda  Mollusca  Annelida  Arthropoda
Phyla: where we’re going.
Echinodermata
?
Chordata
?
Any guesses about these guys?
Here they aaare:
Echinodermata
Chordata