BIO 230 - Invertebrate Zoology

1. BIO 230 - Invertebrate Zoology aka: �Everything you ever wanted to know (and some stuff you didn�t) about the little things that run the Earth.�

2. Classification of Life �Kids Playing Chicken On Freeways Get Squished� What does this mean? Let�s start from the bottom�

3. Classification of Life 3 Domains are Bacteria, Archaea, Eukarya Bacteria/Archaea have prokaryotic cell types No nucleus No cytoskeleton No membrane-bound organelles Eukaryotes Both unicellular and multicellular Nuclei, cytoskeleton, and organelles present

5. Classification: Kingdoms of Eukarya Protozoa (often called Protista) Euglena, Amoeba, etc. Plantae Fungi Animalia

6. Fungi Unicellular or Multicellular Eukaryote Non-motile Heterotrophs � no photosynthesis Have a cell wall A subject of this class?

7. Plantae Multicellular Autotrophs Non-motile Eukaryotes Have a cell wall (cellulose) A subject of this class?

8. Animalia Multicellular Heterotrophs Eukaryotes Most are motile No cell wall A subject of this class?

9. Protozoa Mostly Unicellular Many are colonial, many motile Can be photosynthetic (autotrophs) Some have a cell wall A subject of this class?

10. So, what is an invertebrate? It definitely includes animals�

11. that simply lack vertebra (no true backbone)

12. But� Protists (amoeba, paramecium, euglena) blur the line between animal and plant So we will consider organisms in Kingdoms Animalia & Protozoa But mostly Animalia�

13. Who cares about inverts? You should. Comprise about 98% of animal life on Earth Vertebrates = ~40,000 species Inverts = 2 million described but as many as 8 million still undescribed Found in basically all environments

14. Inverts Incredibly diverse Most small but� Giant squid - 60 ft long & >4,000 lbs Ribbon worms (nemerteans) can grow up to 180 ft long At the other end, rotifers mostly <0.001 mm smaller than some bacteria

15. Inverts Form part of the foundation of most food webs Pollinate flowers & crops Cycle nutrients & waste materials Important food sources Basically form the �backbone� of most ecosystems

16. �If human beings were not so impressed by size alone, they would consider an ant more wonderful than a rhinoceros." "If invertebrates become extinct, the world as we know it would cease to exist." ��. the little things run the world.� -- E.O. Wilson Professor Emeritus Harvard University

17. Diversity of Invertebrates Major Invertebrate Environments Marine Estuaries Freshwater Terrestrial Host organisms

18. Diversity of Invertebrates Land = ca. 22% of surface area Water = ca. 78% Oceans - 97.3% Lakes, ponds, reservoirs (lentic) - 0.009% Rivers (lotic) So, not surprisingly most of invertebrate diversity is in the oceans Why else might this be?

19. Life on land is challenging! Water... allows simple gas exchange across body surface (simpler respiration systems) prevents dehydration (no need for systems to prevent this � e.g. worm mucus) provides movement of sperm and egg and allows for external fertilization flushes away waste is a versatile solvent � makes nutrients available is less dense than air � no need for rigid support and allows easy movement has high specific heat so temps are more stable

20. But� Light is in much shorter supply (extinguishes over a shorter distance) reduces primary productivity Air carries more oxygen than air Oxygen moves 30,000x faster in air Non-moving aquatic organisms need water flow! Water much more viscous so increases drag on larger animals Water sources collect wastes

21. Influences on Invert Diversity