Intro. to Animals

1. Intro. to Animals Ch 32-34

2. Characteristics of animals • multicellular, heterotrophic, eukaryotes • No cell wall • Dominant generation is diploid • Most are motile for some of their life • Also… have embryonic development that forms layers of tissues

3. Embryonic development • 1)Zygote forms and starts cleavage= mitosis of the cell • 2)blastula is formed (a hollow ball) • inside cells are called the blastocoel • 3)Gastrulation occurs in which the tissues start to differentiate – gastrula is formed • Then further development occurs (stem cells)

4. Characteristics and Phylogeny 1) tissue complexity - parazoans – no “true tissues”, when tissues formed = eumetazoa 2) body symmetry • radial = have a top/bottom, no sides/back • bilateral= 2 sides, cut in “identical halves”, top = dorsal, bottom = ventral, front = anterior, back = posterior • cephalization = concentration of senses toward the anterior

5. 3) body cavity = fluid lined space, separates digestive system from the rest of the body • acoelomates – no cavity, solid body • pseudocoelomate = not completely lined cavity • coelomates = true coelom = tissue lined cavity from mesoderm 4) cleavage - early cell divisions of the zygote • protostome – spiral, determinate, first infold forms the mouth • deuterostome – radial, indeterminate, first infold makes anus

8. 5 Points of Agreement, p.662 • 1) All animals share a common ancestor • 2) Sponges are basal animals • 3) Eumetazoa is an animal clade with true tissues • 4) Most animals showcase bilateral symmetry • 5) Chordates and other phyla are deuterostomes

9. Invertebrates (ch 33)

10. (beetles; 350,000 species)

11. The titan beetle of the Amazon

12. Inverts are diverse and account for 95% of all animals

13. Invertebrates Parazoa – closest to protist, non-eumetazoa • 1/1) Phylum “Porifera”- marine, filter feeders, uses pores (spongocoel) and large opening (osculum), lack true tissues, unorganized cells, immobile, hermaphrodites, ex. sponge

14. Radiata – true tissues, radial symmetry 1/2) Phylum Cnidaria - marine, sac with 1 opening for digestion • 2 body forms 1) Medusa = umbrella-like body, dangling tentacles with stinging threads = nematocystsvideo 2) Polyp = sessile, cylinder shaped, rising tentacle 2/2) Phylum Ctenophora – marine, cilia to move, ex. comb jelly

16. Lophotrochozoans, non-deuterostomes with either a crown of ciliated tentacles (lopho) or a distinct larval stage (trocho) 1/6) Phylum Platyhelminthes– Acoelomates – bilateral symmetry, no coelom,most marine, parasites parasite videos, some have digestive "system", have nerve cords, 1 gut opening, ex. Flatworms (planarians), tapeworms, flukes

18. 2/6) Phylum Rotifera – Psuedocoelomates – fake coelom, bilateral, have jaws with cilia, complete digestive track = alimentary canal, first with 2 gut openings, ex. Rotifers Other (less prominent) Lophotrochozoan phyla include: Ectoprocta, Brachiopoda, Acanthocephala, Cyliophora and Nemertea (proboscis worms); see pgs.667-668

19. 3/6) Phylum Mollusca– Protostomes, Coelomates, bilateral Most secrete a hard calcium carbonate shell b/c of soft body • 3 parts: • muscular foot (movement) • visceral mass (organs) • mantle (shell) • ex. snails, bivalves, slugs, octopus, squid, p677-678

20. How many parts can you label?

21. Figure 33.20 Coelom Hinge area Mantle Heart Gut Adductor muscle (one or two) Digestive gland Anus Mouth Excurrent siphon Shell Water flow Palp Foot Incurrent siphon Mantle cavity Gonad Gill

22. cephalopods Squid Octopus Chambered nautilus

24. 4/6) Phylum Annelida– protostomes, coelomates, segmented worms, some parasitic or decomposers, brain like ganglia at the front, pumping vessels for blood flow, hermaphrodites, ex. leeches, earthworms • Why is coelom and segmentation important? • cushion and specialization; hydrostatic skeleton

26. The last two lophophores • 5/6 Ectoprocta: The Bryozoa, also known as Ectoprocta or commonly as moss animalsare a phylum of aquatic invertebrate animals • 6/6 brachiopods

27. Ecdysozoans, secrete exoskeletons 1/2) Phylum Nematoda - roundworms, unsegmented, pseudocoelomates, live in soil, decomposers, periodically shed cuticle, sexual repro., ex. C.elegans

28. 2/2) Phylum Arthropoda- segmented, jointed appendages, exoskeleton of chitin, developed N.S, different life cycles (metamorphosis- eggs, larvae, pupa, adult), open circulatory system, heart, more complex gas exchange, most in numbers, ex. insects, spiders, crustaceans

29. Figure 33.32b 50 m Dust mite

30. Figure 33.30 Cephalothorax Abdomen Thorax Antennae (sensory reception) Head Swimming appen- dages (one pair per abdominal segment Walking legs Mouthparts (feeding) Pincer (defense)

31. Figure 33.37 (a) Larva (caterpillar) (b) Pupa (c) Later-stage pupa (d) Emerging adult (e) Adult

33. Deuterostomes, “second mouth” 1/2) Phylum Chordata (non-invert, next chapter) 2/2) Phylum Echinodermata - radial, water vascular system, tube feet that aid in movement, feeding and gas exchange, marine, complete digestive track, ex. sea star, sea urchin

34. Figure 33.42

36. Invertebrate quick check… Invertebrates: Porifera, Cnidaria, Platyhelminthes, Nematoda, Annelida, Mollusca, Arthropoda, Echinodermata • Which group includes snails, clams, and squid? • Which group is the sponges? • Which are the flatworms? • …segmented worms? • …roundworms? • Which group has jointed appendages & an exoskeleton? • Which two groups have radial symmetry? • What is the adaptive advantage of bilateral symmetry? • Which group has no symmetry?

37. Phylum Chordata (ch 34)

38. 2) Phylum Chordata – bilateral, coelomates with segmented bodies; includes 2 invertebrate groups → lancelets, tunicates (closest invertebrate to human) and then the vertebrates

39. Common features 1) Notochord - dorsal flexible fluid filled rod, support, usually replaced by bone during development 2) Dorsal hollow nerve cord - basis for nervous system, brain/spine 3) Pharyngeal gill slits – can become gills for O2 exchange or filter feeding 4) Muscular tail – postanal, muscles/bones for movement - also have neural crest (specialization cells), cephalization, vert. column and closed circulatory system

41. Phylogeny – p699

42. Vertebrates • More complex nervous system • More elaborate skeleton (have bones that enclose the spinal cord) • Have the 4 common features at some point in development, may disappear • More efficient at • Capturing food • Avoiding being eaten • ** p.704

43. Class Myxini - jawless fishlike animals, no appendages, in water, p.703, ex. Hagfish • Class Petromyzontida – p.704, ex. lampreys 3) Class Chondrichthyes – jaws , cartilaginous fish, fins, gills, lay eggs (oviparous), or hatch in uterus (ovoviparous), (humans are viviparous – nourish in womb), p.706, ex. sharks, skates, rays 4) Class Osteichthyes - bony fish, most lay eggs, gills, swim bladder (air sac= buoyancy), ex. tuna, bass, trout, p.708 basic structure, ray-finned vs. lobe-finned

44. Figure 34.9 Hagfishes Slime glands

45. Figure 34.10 Lampreys

46. Figure 34.11 Conodonts were the first vertebrates with mineralized skeletal elements Dental elements(within head)

47. Figure 34.13 Gill slits Cranium Mouth Skeletal rods

48. Figure 34.15 Chondrichthyans (Sharks, Rays, and Their Relatives) Dorsal fins Pectoralfins Pelvic fins (a) Blacktip reef shark (Carcharhinus melanopterus) (b) Southern stingray (Dasyatis americana) (c) Spotted ratfish (Hydrolagus colliei)

49. Figure 34.17 Yellowfin tuna (Thunnus albacares) Redlionfish(Pteroisvolitans) Commonsea horse(Hippocampusramulosus) Fine-spotted moray eel(Gymnothorax dovii)

50. 5) Class Amphibia – “both ways of life” appendages to walk on land (tetrapods), aquatic larval stage then terrestrial adult, lay eggs (amniotic sac) or live birth, respire via lungs or skin, p.712, ex. frog, salamander