characteristics that differentiate animals: levels of organization (cells, tissues, organs, organ...

Characteristics that differentiate animals:

• Levels of organization (cells, tissues, organs, organ systems)

• Body symmetry (none, radial or bilateral)

• Germ layers (endoderm, mesoderm, ectoderm)

• Body cavity (acoelom, pseudocoelom, coelom)

• Type of body: Segmentation (repeating parts), cephalization (getting a head), limb formation (legs, flippers, wings)

• Systems (digestive, circulatory), Reproduction (asexual or sexual), Homeostasis (body temperature)

• Type of skeleton (endo- or exoskeleton)

• Incomplete digestive system – filter feeders

• Invertebrates

• Asexual and sexual reproduction

• Examples: sponges

Levels of Organization Specialized cells

Body Symmetry Asymmetrical (none)

Germ Layers Absent

Body Cavity ----

Embryological Development

----

Segmentation Absent

Cephalization Absent

• Invertebrates

• Examples: jellyfish, hydra, sea anemones, coral

Levels of Organization Specialized cells, tissues

Body Symmetry Radial

Germ Layers Two

Body Cavity Acoelom (gastrovascular cavity digests and circulates nutrients)

Embryological Development

----

Segmentation Absent

Cephalization Absent

• Invertebrates

• Flattened body

• Includes many parasites

• Examples: planaria, tapeworms, many parasites

Levels of Organization Specialized cells, tissues, organs

Body Symmetry Bilateral

Germ Layers Three

Body Cavity Acoelom (Gastrovascular cavity digests and circulates nutrients)

Embryological Development Protostome

Segmentation Absent

Cephalization Present! Can you see the head of these flatworms?

• Have a mouth and anus

• Sexual reproduction

• Ex: Ascaris is a parasitic roundwormthat lives in intestines ofpigs and humans

Levels of Organization Specialized cells, tissues, organs

Body Symmetry Bilateral

Germ Layers 3 germ layers

Body Cavity Pseudocoelom

Embryological Development Protostome

Segmentation Absent

Cephalization Present (look for the mouth)

• Primitive circulatory system

• Reproductive openings

• Ex: earthworms, leeches

Levels of Organization Specialized cells, tissues, organs

Body Symmetry Bilateral

Germ Layers Three

Body Cavity True coelom (complete digestive system)

Embryological Development

Protostome

Segmentation Present (ring-like segments)

Cephalization Present

• Some can move with a muscular foot

Squids and octopiClams and oystersSnails, slugsChitons

Levels of Organization Specialized cells, tissues, organs

Body Symmetry Bilateral

Germ Layers Three

Body Cavity True coelom

Embryological Development Protostome

Segmentation No segmentation

Cephalization Present

• Most successful animal phylum based on species diversity and distribution

• Invertebrates

• Jointed appendages

• Exoskeleton

• Examples: insects, spiders, butterflies,crustaceans (lobster, crab), grasshoppers

Levels of Organization Specialized cells, tissues, organs

Body Symmetry Bilateral

Germ Layers Three

Body Cavity True coelom

Embryological Development

Protostome

Segmentation Segmented body – head, thorax, abdomen

Cephalization Present

• Invertebrates

• Arms, and tube feet

• Complete digestive tract

• Closed circulatory system

• Ex: Starfish, sea urchin, sand dollar, sea cucumber

Levels of Organization Specialized cells, tissues, organs

Body Symmetry Radial (as adults)

Germ Layers Three

Body Cavity True coelom

Embryological Development

Deuterostome

Segmentation Absent

Cephalization Absent (as adults)

• Mostly vertebrates (includes invertebrate chordates too)

• Animals in this phylum have a dorsal hollow nerve cord (eventually becomes spinal cord)

• Don’t necessarily have a bony vertebral column

• Simple circulatory system

• Examples of some invertebratechordates: sea squirts, tunicates

• Ex. of vertebrate chordates in upcoming stations (10-17)

Tunicates

Sea squirts

(Vertebrates) Key Characteristics:

- Notochord replaced by cartilage or bony vertebral column

- 7 Major Classes within Vertebrata:

1. Agnatha (jawless fish)

2. Chondrichthyes (cartilaginous fish)

3. Osteichthyes (bony fish)

4. Amphibia (amphibians)

5. Reptilia (reptiles)

6. Aves (birds)

7. Mammalia (mammals)

• No jaws

• No scales – have SKIN!

• 7 or 12 gill slits

• Continuous median fin

• Examples: Hagfish (body made of collagen - rare)Lamprey (has vertebrae)

The hagfish is black

• Flexible skeleton of cartilage

• Jaws and paired appendages

• Lateral line sensory system

• Scales

• 5 gill slits

• Ex: sharks, rays

• Bony skeleton

• Operculum (flap) protecting gills and allows fish to breathe without swimming

• Scales

• Different position of fins and mouth

• Swim bladder (derivative of lung)

• Ex: Eels, salmon, carp, catfish, walleye, cod

• Larva with functional gills

• Eggs deposited in water

• Undergo metamorphosis

• Develop lungs

• Four limbs

•Ex: frogs, toads,

salamanders, newts

Tadpole

• Internal fertilization

• Amniotic egg

• No larval stage

• Breathe air (lungs)

• Ectothermic (cold blooded)

• Epidermal scales

• Ex: turtles, crocodiles, snakes, lizards

• Forelimbs modified to wings

• Feathers

• Hollow bones

• Lay shelled eggs

• Endothermic (warm blooded)

• Ex: eagles, blue jays, pelicans, etc.

• Mammary glands (produce milk)

• Hair or fur

• Endothermic (warm blooded)

• Examples: humans, cats, dogs, squirrels, horses, etc.