About Marine Invertebrate

1. Introduction to Animals
Invertebrate Evolution and Diversity
Chapter 25
Chapter 26.1

2. Introduction to Animals
Chapter 25

3. Characteristics of Animals
• Kingdom – Animalia
• Multicellular
• Heterotrophic
• Eukaryotic
• Lack cell wall

4. Types of Animals
• Invertebrates
–Lack backbone or vertebral column
–95% of animals
–Sea stars, worms, jellyfish, insects

5. •Chordates
Exhibit four characteristics during at least one
stage of life
–Dorsal, hollow nerve cord
–Notochord
–Tail that extends beyond anus
–Pharyngeal pouches
Lancelet

6. • Chordates with backbones = Vertebrates
–Fishes, amphibians, reptiles, birds,
mammals

7. What Animals Do to Survive
1. Maintain homeostasis by gathering and
responding to information
– Feedback inhibition

8. 2. Obtain and distribute oxygen and nutrients
3. Collect and eliminate CO2 and waste
4. Reproduce

9. Animal Development
Animals have a wide variety of forms.
The following developmental factors determine the body plan:
 Levels of organization : cells, tissue, organ, organ systems
 Arrangement of Germ layers:
 differentiate into different tissue types:
• Endoderm (inner): digestive tract
• mesoderm (middle): muscles, blood
• ectoderm (outer): skin, nervous system

10. Development, cont.
 Overall Patterns of
Embryological
Development
– Protostomes
• Blastopore becomes mouth
• Most invertebrates
– Deuterostomes
• Blastopore becomes anus
• Chordates, Echinoderms
(sea stars)

11. Development, cont.
Body Cavity Formation
Coelom – completely lined with tissue derived
from mesoderm
Acoelom – lack a body cavity
Pseudocoelom – partially lined with mesoderm

12. Development, cont.
 Body symmetry:
• Radial
–body parts extend from a central point
–Divides into equal halves
• Bilateral
–Right and left sides are mirror images of each
other
–Distinct anterior and posterior ends and dorsal
and ventral sides

14.  Segmentation
– Repeating Parts
– Worms, insects, vertebrates
 Cephalization
– concentration of sense organs and nerve cells at
anterior end (head)
 Limb Formation
– Legs, Flippers, Wings

16. Cladogram of Animals
• Phyla defined by:
– Adult body plans
– Patterns of embryological development
• Ex. Phylum Arthropoda
– Body plan bilateral symmetry
– Segmentation
– Cephalization
– External skeleton
– Jointed legs

18. Invertebrate Evolution and Diversity
• Cladogram of invertebrates determined by
– evolutionary relationships among major groups
– sequence of evolution of important features

19. • Sponges
– Phylum: Porifera (“pore bearers”)
– Most ancient member of kingdom Animalia
– Multicellular, heterotrophic, lack cell walls, contain
few specialized cells
– Clade Metazoa

20. • Cnidarians
– jellyfishes, sea fans, sea anemones, hydras, corals
– Aquatic, soft-bodied, carnivorous, radially
symmetrical, stinging tentacles around mouths
– Simplest animals with body symmetry and
specialized tissues

21. • Nematoda (Roundworms)
– Unsegmented worms
– Pseudocoeloms
– Specialized tissues and organs
– Digestive tract with two openings

22. • Platyhelminthes
– Flatworms
– Soft
– Unsegmented
– Have tissues and internal organ systems
– Bilateral symmetry
– Cephalization
– Do not have coeloms

23. • Annelids
– earthworms, some marine worms, leeches
– Segmented bodies
– True coelom lined with tissue derived from
mesoderm

24. • Arthropods
– Phylum: Arthropoda – spiders, centipedes, insects,
crustaceans
– Bodies divided into segments
– Exoskeleton
– Cephalization
– Jointed appendages

25. • Mollusks
– Phylum: Mollusca – snails, slugs, clams, squids, octopi
– Soft-bodied
– Internal or external shell
– True coeloms surrounded by mesoderm and complex
organ systems
– Free-swimming larva

26. • Echinoderms
– Phylum: Echinodermata – sea stars, sea urchins, sand
dollars
– Spiny skin
– Internal skeleton
– Water vascular system – used for walking and gripping
prey
– Five-part radial symmetry

29. Animals
Chordates Invertebrates
Cnidaria
Hexacorallia
R. daphneae
Other invert.
Other Cnidaria
Other Hexacorallia
Kingdom:
Sub-kingdom:
Phylum:
Class:
Order: