Invertebrate Overview: Kingdom Animalia

1
Invertebrate OverviewKingdom Animalia

• Phylum Porifera -sponges
• Phylum Cnidaria -jellyfish, sea anemones
• Phylum Platyhelminthes -tapeworms, flukes
• Phylum Nematoda -pinworms, Ascaris
• Phylum Mollusca -clams, squid, octopi
• Phylum Annelida -earthworms, leeches
• Phylum Arthropoda -insects, crayfish
• Phylum Echinodermata -starfish, sand dollars

2
Phylum Porifera

• Ex. Sponges
• Multicellular WITHOUT TISSUES
• Heterotrophic filter feeders
• Asymmetrical
• No cephalization present
• No coelom
• Basic body parts ostia, spongocoel, osculum,
  choanocytes with flagella

3
Figure 33.2 Sponges
4
Figure 33.3 Anatomy of a sponge
5
Phylum Cnidaria

• Ex. Jellyfish
• Two germ layers ectoderm and endoderm
• No cephalization
• No coelom
• Soft, sac-like body plan, two way digestion (with
  one opening mouth)
• Two body forms sessile polyp and free-swimming
  medusa
• Basic body parts bell, cnidocytes with
  nematocysts, tentacles, gastrovascular cavity,
  gonads

6
Figure 33.4bx Jelly medusa
7
Table 33.1 Classes of Phylum Cnidaria
8
Figure 33.4 Polyp and medusa forms of cnidarians
9
Figure 33.5 A cnidocyte of a hydra
10
Phylum Platyhelminthes

• Ex tapeworms
• Three germ layers ectoderm, mesoderm, endoderm
• Bilateral symmetry
• Cephalization is present
• No coelom acoelomates!!!!
• Use diffusion to transport materials through body
• Mouth forms first protostomes
• Basic body parts mouth, pharynx, intestine,
  ganglia, flame cells

11
Figure 33.9x A flatworm
12
Figure 33.10 Anatomy of a planarian
13
Figure 33.12 Anatomy of a tapeworm
14
Phylum Nematoda

• Ex. Pinworms
• Three germ layers present ectoderm, mesoderm,
  endoderm
• unsegmented
• Bilateral symmetry
• Cephalization present
• Pseudocoelom present
• Mouth forms first protostome
• Basic body parts mouth, anus, intestines

15
Figure 33.25a Free-living nematode
16
Figure 33.25ax Nematode, C. elegans
17
Phylum Mollusca

• Ex. Clam, squid
• Three germ layers present ectoderm, mesoderm,
  endoderm
• Have an external or internal shell for support
• Bilateral symmetry
• Cephalization present
• Has a TRUE COELOM
• Mouth develops first protostome
• Basic body parts gills, specialized foot

18
Table 33.3 Major Classes of Phylum Mollusca
19
Figure 33.18x Garden snail
20
Figure 33.20 A bivalve Scallop
21
Figure 33.22 Cephalopods Squid (top left and
bottom left), nautilus (top right), octopus
(bottom right)
22
Phylum Annelida

• Ex earthworm
• Three germ layers present
• Bilateral symmetry present
• Cephalization present
• True coelom present
• Mouth develops first protostome
• Basic body parts mouth, anus, specialized
  intestine, segments

23
Figure 33.23x External anatomy of an earthworm
24
Figure 33.23 Anatomy of an earthworm
25
Phylum Arthropoda

• Ex. Insects, spiders, crayfish, millipedes,
  centipedes
• Three germ layers present
• Exoskeleton present that requires molting
  (shedding)
• Jointed appendages
• Bilateral symmetry
• Cephalization present
• True coelom present
• Mouth forms first
• Basic body parts head, thorax, abdomen, (or
  cephalothorax and abdomen), spiracles and
  tracheae, open circulatory system

26
Table 33.5 Some Major Arthropod Classes
27
Figure 33.26 External anatomy of an arthropod
28
Figure 33.30b Spider anatomy
29
Figure 33.33 Anatomy of a grasshopper, an insect
30
Phylum Echinodermata

• Ex starfish
• 3 germ layers present
• Biradial symmetry in adults
• No cephalization in adults
• True coelom present
• Anus forms first deuterostome!!!
• Basic body parts spiny skin, endoskeleton,
  water vascular system, tube feet

31
Figure 33.37 Echinoderms Sea star (top left),
brittle star (top right), sea urchin (bottom
left), sea lily (bottom right),
32
Figure 33.38 Anatomy of a sea star
33
Figure 32.1 Early embryonic development (Layer 3)
34
Figure 32.7 A comparison of early development in
protostomes and deuterostomes