Animal Diversity BSC 2011L

1. Animal DiversityBSC 2011L

2. Major Divisions of Life Eukaryotes * Bacteria Archaea Microsporidia Flagellata Animalia Fungi Ciliata Plantae *membrane bound nucleus

3. Major Divisions of Life Bacteria Archaea Microsporidia Flagellata Animalia Fungi Ciliata Plantae Multicellular

4. Major Divisions of Life These multicellular groups were divided based on feeding mode & fundamental organizational differences. Animalia Fungi Plantae • heterotrophic • (ingest and digest food) • no cell walls • heterotrophic • (absorb food) • cell walls made of chitin • autotrophic • (photosynthesis) • cell walls made of cellulose

5. Diversity of Animal Life

6. What is an animal? • multicellular (Branch Metazoa) • eukaryote • heterotrophic • blastula stage • generally motile

7. How are these animals grouped? • Complexity • level of organization • Morphology • general body plan • symmetry • comparative biochemistry • Development • type of developmental patterns

8. Level of Organization Cell • no tissues, no organs • individual cells accomplish physiological functions Tissue • cells are organized into tissues and work together to accomplish physiological functions Organ • tissues are organized into organs that accomplish physiological functions

9. General Body Plan • presence of different body structures • does it have a head? • does it have a backbone? • does it have tentacles? etc… • solutions to different body functions • how do they move? • how do they feed? • how do they reproduce? etc…

10. Types of Symmetry • the arrangement of body structures relative to some axis of the body Asymmetrical Radial Bilaterial

11. Comparative Biochemistry • comparing DNA and amino acid sequences among animals

12. Developmental Patterns • type of cell cleavage • type of embryo development • presence, type, and formation of a body cavity • etc… sea urchin

13. Taxonomic Hierarchy Linnaen system of binomial nomenclature example - Humans Kingdom Animalia Phylum Chordata Class Mammalia Order Primates Family Hominidae Genus Homo Species sapiens * the plural of Phylum = Phyla *

14. Phylum Porifera the sponges

15. Phylum Porifera Branch Parazoa – “beside + animal” Sponges are at the cellular level of organization and have no tissues or organs. Sponges are assemblages of cells embedded in a protein matrix and supported by a skeleton of needle-like structures.

16. External Morphology

17. General Body Plan osculum (plural=oscula) spongocoel ostia (singular=ostium) water

18. 3 Body Types Based on the complexity of the water canals: • Asconoid • Syconoid • Leuconoid Increasing size Increasing SA:V

19. Asconoid Body Type osculum spongocoel ostium * spongocoel is lined with choanocytes *

20. Asconoid Body Type osculum spongocoel water ostium

21. incurrent canal osculum ostium spongocoel prosopyle apopyle radial canal Syconoid Body Type * radial canals are lined with choanocytes *

22. incurrent canal osculum ostium spongocoel prosopyle apopyle radial canal Syconoid Body Type water

23. Leuconoid Body Type osculum spongocoel apopyle ostium incurrent canal flagellated chambers prosopyle * flagellated chambers are lined with choanocytes *

24. Leuconoid Body Type osculum spongocoel water apopyle ostium incurrent canal flagellated chambers prosopyle

25. Microscopic Morphology archaeocyte (amoebocyte) porocyte choanocyte pinacocyte mesohyl spicules

26. Skeletal Elements • Mesohyl • proteinaceous matrix that contains skeletal material and certain cell types • equivalent to the connective tissue in other organisms • made of collagen • and spongin

27. Skeletal Elements • Spicules • made of calcium carbonate or silica • often used in taxonomic identification

28. Cell Types • Choanocytes • collar cells • diagnostic of phylum Porifera • consist of a long flagellum surrounded by a “collar” of microvilli • functions: • obtaining food • creating water currents • reproduction

29. Cell Types • Archaeocytes • also called “amoebocytes” • found throughout mesohyl • totipotent  can differentiate into any other type of cell • functions: • digestion through phagocytosis • make spicules • reproduction

30. Cell Types • Pinacocytes • line the exterior surface of the sponge • functions: • some can regulate water flow by moving (open/close ostia) outside of sponge inside of sponge

31. Cell Types • Porocytes • found in asconoid sponges • form tubes in the body wall where water can pass through • functions: • allow water flow outside of sponge inside of sponge

32. Physiology Feeding • Sessile filter-feeders Digestion • Intracellular Gas exchange • Simple diffusion Excretion (nitrogenous waste removal) • Simple diffusion

33. Physiology Reproduction Asexual • fragmentation • budding • regeneration • gemmules - in freshwater sponges only - resistant mass of archaeocytes that are produced in unfavorable conditions - when the environment is nice again, they will develop into sponges

34. Physiology Reproduction Sexual • usually monoecious (a single individual can produce both male and female gametes; both sexes are within one individual) • sperm are released into the water and eggs are retained within the sponge • motile larvae are produced (some swim, some crawl), metamorphose, and become juvenile sponges

35. Ecology • most sponges are marine (~5000 species) but there are ~150 freshwater sponge species • Sponges are found at all depths but certain species are restricted to particular depths due to how their spicules are formed • There are few sponge predators because they usually contain distasteful toxins • Some predators (e.g. sea slugs) sequester these sponge toxins which in turn deters their own predators

36. Ecology Symbiosis – the living together of 2 different species in an intimate relationship Types of symbiotic relationships: • Mutualism= both partners benefit • Commensalism= 1 partner benefits, 1 partner is unaffected • Parasitism= 1 partner benefits, 1 partner is harmed There are examples of all 3 of these types of symbiotic relationships occurring in Sponges

37. Ecology Mutualism – • certain ‘endosymbiotic’ bacteria and algae living within the sponge provide additional food for the sponge while the sponge provides a place for the bacteria and algae to grow • some crabs will attach a piece of sponge to their body to use as camouflage and to deter predators while the sponge gets to move around

38. Ecology Commensalism – • many different species live within sponges and receive food and shelter benefits but do nothing for the sponge e.g. 15cm² piece of sponge in California was found to house 100 different species of plants + animals e.g.Venus’s Flower basket a pair of shrimp live their entire lives within 1 sponge

39. Ecology Parasitism – • boring sponges are parasites on certain corals because they bore into the calcium carbonate base of the coral for protection and kill part of the coral in the process

40. Current Sponge Research Chemical defenses – • the compounds that sponges use to defend themselves from predators are being researched for potential biomedical applications Cell-cell communication – • although sponges have no nervous system, cells are capable of communicating with one another • Sponges can also recognize foreign cells and particles and mount an immune response Animal Evolution – • relationship between sponges and all other Metazoans remains unclear