12/4/2013
BI 101: Invertebrate Animals
Announcements
• Lab tomorrow: Invertebrates ( lab worksheet provided) – 8 am start – No prelab
• Holiday: No class Friday!
1 12/4/2013
Classification
The three-domains Bacteria Archaea Eukarya
The six-kingdom system Bacteria Archaea Protista Plantae Fungi Animalia
The traditional five-kingdom system Monera Protista Plantae Fungi Animalia
(Forams and Radiolarians) Rhizarians Alveolates Rhodophyta Stramenopile
CHLOROPHYTA Euglenozoa AMOEBOZOANS
2 12/4/2013
What are some characteristics animals share? List as many as you can think of. Discuss this in your groups
Animal Cell
Fungus Cell
3 12/4/2013
Evidence indicates that animals evolved from choanoflagellates (protists) ~ 570 mya
• Single cells • Often clonal • Heterotroph • No specialization or coodination between cells
Animal Classification
1. DNA sequencing
2. Body Symmetry
3. Presence or absence of body cavity
4. Embyonic Development
4 12/4/2013
Symmetry
Body Cavity
Most bilateral animals have body cavities – Body cavities are fluid-filled cavities between the digestive tube and the outer body wall – Functions: • skeleton, providing support for the body and a framework against which muscles can act • protective buffer between the internal organs and the outside world • They can allow organs to move independently of the body wall
5 12/4/2013
Body Cavity?
epidermis gut cavity
organs packed between A No coelom gut and body wall (acoelomate animal)
Fig. 25-4a, p. 405
Body Cavity?
epidermis gut cavity
B Pseudocoel (pseudocoelomate animal) unlined body cavity around gut
Fig. 25-4b, p. 405
6 12/4/2013
Body Cavity?
gut epidermis cavity
C Coelom body cavity with a lining (dark (coelomate animal) blue) derived from mesoderm
Fig. 25-4c, p. 405
Embryonic Development Blastopore forms Protostomes mouth first
Deuterostomes
Blastopore forms anus first
7 12/4/2013
What is the difference between vertebrates and invertebrates?
8 12/4/2013
Porifora - sponges
• Sessile (Larva motile) • No true tissues or organs • Exhibit asymmetry or radial symmetry • Filter feeders
(water flow out Sponge Anatomy of the sponge)
epithelial cell pore
spicules (water flow into the sponge)
amoeboid cell
pore cell
collar cell
(water flow) Fig. 23-5
9 12/4/2013
Sponge filtration/feeding
Collar Cell
Collar Cell http://www.youtube.com/ watch?v=T7E1rq7zHLc&feat ure=player_embedded http://www.youtube.com/watch?v =29W77870BgE&list=PLVN5247pO BYcE1Mn_pWHIL9l0sMIx19TI
Sponges for Breast Cancer Research! • The artificial component called eribulin mesylate imitates an element found in sponges.
• It can check cell division, which is a reason of cells to self-damage.
• http://www.topnews.com.sg/content/22106-marine- sponge-probable-treatment-breast-cancer
10 12/4/2013
Cnidaria – Sea Anemone
• Radial symmetry • Two tissue layers • Filled with water– supports body • Nerve net • Nematocysts -stinging organelles that release toxins
11 12/4/2013
Cnidarian Weaponry: The Cnidocyte
trigger filament
trigger
nuclei
(b) Cnidocytes Fig. 23-8
Cnidaria: Symbiosis
Coral is a mutualism between photosynthetic dinoflagellates (protist) and a cniderian (animal) • Algae in coral called zooxanthelle
12 12/4/2013
In many coral species polyps form colonies
Cnideria video
Colonial polyps secrete a hard external skeleton of calcium carbonate The skeleton remains after the polyp dies New polyps build on the skeletal remnants of earlier generations
13 12/4/2013
Platyhelminthes - flatworms
• Bilateral symmetry • 3 tissue layers • Cephalization (nerve mass) • True organs and organ systems • Aceolomate (no body cavity) • Parasitic forms but some free living
14 12/4/2013
Announcements
• Quiz 7 today
• Final exam next Monday • 8-10am (longer if needed) • Study both Midterm & Final study guide • Study groups encouraged!
Evolved ~500 mya
15 12/4/2013
Mollusca Characteristics:
• bilateral symmetry • Coelomates- true body cavity • Unsegmented • aquatic & terrestrial • possess all organ systems
Mollusca Diversity 2nd most diverse animal group: 93,000 species
Gastropods Cephalopods Bivalves 80% of mollusk Most neurologically Aquatic species advanced • Clams • Snails Marine predators • Mussels • Slugs • Octopus • Nudibranchs • Squid • Cuttlefish
16 12/4/2013
Nudibranchs • 3,000 described species • Snails without a shell • Unique lifestyle and defense mechanisms Elysia– the photosynthetic animal (video)
Glaucus atlanticus consumes ‘man of war’ jellyfish and puts the nematocytes on its own back!
Nudibranchs
The Blue Dragon, Pteraeolidia ianthina, has a symbiosis with dinoflagellates. It also steals the armed tentacles of a sea anemone, a Cniderian, for defense and combat!
17 12/4/2013
Annelida - segmented worms
Fig. 32-8 Coelom Body covering • Segmented body (from ectoderm)
• Bilateral symmetry Tissue layer lining coelom • 3 tissue layers Digestive tract and suspending (from endoderm) internal organs • Coelom (fully enclosed (from mesoderm) body cavity) (a) Coelomate Body covering • Organ systems are more (from ectoderm)
fully developed Pseudocoelom Muscle layer (from mesoderm) • Decomposers and Digestive tract (from endoderm) Parasites (b) Pseudocoelomate
Body covering (from ectoderm) Tissue- filled region (from mesoderm)
Wall of digestive cavity (from endoderm) 18 (c) Acoelomate 12/4/2013
Annelida - segmented worms • Class: Polychaetes – Each segment with many hairlike chetae – 12,000 species – Mostly marine
• Class: Clitellata – Earthworms - Oligochaete 10,000 species Terrestrial Decomposers
– Leeches – Hirudinea 700 species Predators or parasites Most freshwater
Discussion questions
1. How do earthworms differ from tapeworms and planarians?
19 12/4/2013
Fig. 32-8 Nematoda - Round worms Coelom Body covering • Exoskeleton (molts)– 25,000 (fromspecies ectoderm) body coved in a thick Tissue layer cuticle lining coelom Digestive tract and suspending • Psuedocoelom (false (from endoderm) internal organs (from mesoderm) body cavity) • Bilateral worms (a) Coelomate
• 3 tissue layers Body covering • Unsegmented (from ectoderm) Pseudocoelom Muscle layer • Parasitic (50%) (from and free-living (50%) mesoderm) Digestive tract (from endoderm) (b) Pseudocoelomate
Body covering (from ectoderm) Tissue- filled region (from 20 mesoderm)
Wall of digestive cavity (from endoderm)
(c) Acoelomate 12/4/2013
A Freshwater Nematode
posterior end intestine
anterior end
ovary vagina eggs mouth cuticle Fig. 23-25
Discussion questions
1. How do earthworms differ from tapeworms and planarians?
2. How do earthworms differ from nematodes?
21 12/4/2013
Arthropoda– Earth’s most diverse phylum Billions of species!
Major groups: • Crustaceans • Myriopods • Arachnids • Hexapods
22 12/4/2013
Arthropoda Characteristics
1. Exoskeleton= External skeleton 2. Specialized body segments 3. Jointed appendages 4. Bilateral symmetry 5. True coelom (body cavity)
Arthropoda respiratory system: Trachea
23 12/4/2013
Arthropoda respiratory system: Example: Grasshopper • Spiracles: pores in exoskeleton • Trachea: connect to spiracles, carry oxygen to the body cells
Arthropoda respiratory system
24 12/4/2013
Arthropod Phylogeny
Chelicerata
8 legs • Arachnids – spiders, – Mites – Ticks – scorpions • Horseshoe crabs • Pseudoscorpians
25 12/4/2013
Arthropod Phylogeny
Crustaceans
Rolly pollies– Isopods Lobsters Crayfish Crabs Shrimp Krill Baracles
26 12/4/2013
Arthropod Phylogeny
Myripoda
• Class: Symphyta
• Class: Chilopoda (centipedes)
• Class: Diplopoda (millipeds)
27 12/4/2013
Arthropod Phylogeny
Diplura Insecta
Protura Collembola
Hexapoda: Reduction in body segments to 3
Reduction in legs to 6
Arthropod Phylogeny
Thysanaura
: :
Slverfish
Archaegnatha
Diplura
Protura Collembola
Wings!
Insecta: mouthparts outside head capsule Hexapoda: Reduction in body segments to 3 Reduction in legs to 6
28 12/4/2013
Figure 23-19 Segments are fused and specialized in insects
antennae head thorax abdomen compound eye mouth parts
wing
Specializations for Feeding
Grasshoppers (a) – mouth has numerous manipulating and shearing parts for eating vegetation. Flies (b) – has a labium mouth part that has a sponge like end for absorbing nutrients from moist foods. Butterflies & Moths (c) – mouth part is a tube like maxilla for sucking up nectar from flowers. Mosquitoes (d) – have a stylus for piercing their prey to draw blood like a hypodermic needle.
29 12/4/2013
Insect Development
Discussion
Why might it be advantageous for insects to have complete metamorphosis?
30 12/4/2013
31 12/4/2013
Phylum Echinodermata 6,000 species Includes sand dollars, sea urchins, sea stars, sea cucumbers, and sea lilies
Three tissue layers True coelom
Echinodermata characteristics 1. Deuterostomes
32 12/4/2013
Echinodermata characteristics 2. Larvae exhibit bilateral symmetry; adults show radial symmetry
Echinodermata characteristics 3. Endoskeleton (internal skeleton) that sends projections through the skin Composed of calcareous plates or ossicles
33 12/4/2013
Echinodermata characteristics
4. Water vascular system: Food and waste transport Respiration Locomotion
Discussion question
• How do sea urchins and sea stars differ from sea anemones and coral?
VS
34 12/4/2013
Animal Diversity Ancestral Derived
Radial Symmetry Bilateral
0, 2 # of tissue layers 3
1 # gut openings 2
Acoelomate, Type of coelom Eucoelomate Pseudocoelomate Type of development Protostome Deuterostome
35