kingdom animalia eukaryotic no cell wall multicellular heterotrophic most are capable of motion...

Kingdom Animalia

• Eukaryotic• No cell wall• Multicellular• Heterotrophic• Most are capable of motion• About 30 phyla

Characteristics for animal classification

• Symmetry-the arrangement of body parts around the main axis of the body1. Bilateral-two almost identical halves2.Radial symmetry around the axis

3. Asymmetrical-lack of symmetry• Digestive systems: sac or tube where food

breaks down into small particles1. Incomplete-one opening2. Complete-two openings

3. Absent

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Figure 23.3  Symmetry Is an Equivalence in Body Sections

Radial symmetry:Symmetry around a central point

Asymmetry:No planes of symmetry

Bilateral symmetry:

Characteristics for animal classification

• Body Segmentation-multiple repeating units• Skeletal systems: provide support for the

body1.Exoskeleton - a hard skeleton on the outside

of the body (calcium carbonate shells, chitin, silica)

2.Endoskeleton - a hard skeleton inside the body, usually composed of bone or cartilage

Characteristics for animal classification

• Circulatory systems-distribute nutrients to all parts of the body and removes waste products. [Not found in Cnidaria, Platyhelminthes, or Nematoda].1.Closed-the blood is always inside of blood vessels (all vertebrates, some molluscs).2.Open-the blood fills the body cavity (arthropods, some molluscs)

Classification system• domain • kingdom - a group of related phyla• phylum (plural = phyla) - a group of related classes. It is called a division in Botany. • class - a group of related orders• order - a group of related families• family - a group of related genera• genus (plural = genera) - a group of related species• species - a kind of living organism . All organisms who can potentially reproduce together under

natural conditions and produce fertile offspring.

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Figure 23.2  A Family Tree for Animals

ancestral protist

tissuessymmetry

Protostomes Deuterostomesbilateral symmetry

(sponges) (flatworms) (roundworms)

Porifera Cnidaria Platyhelminthes NematodaMolluscaAnnelida Arthropoda Echinodermata Chordata

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mouthanus

mouth anus

invagination

invagination

blastopore

blastopore

Protostomes

Early embryo

Deuterostomes

All animals pass through a blastula stage of development, the blastula being a hollow ball of cells. The blastula then invaginates to form a structure that develops into the animal’s gut. The opening to this invagination is called a blastopore. In protostomes, the blastopore becomes the mouth. In deuterostomes, by contrast, the blastopore becomes the anus.

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Table 23.1  Animal Phyla

Phylum Porifera ( pore-filled)

• Example: Sponges• Asymmetry or radial symmetry• Endoskeleton• Filter feeders (body with pores)• They are attached (cannot move)• marine

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Figure 23.6  Sponges: A Body Plan for a Simple Lifestyle

Inner cells withflagella createcurrents.

The currentscause water toflow into poresand out at top.

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Figure 23.7  Sponge Diversity

Phylum Cnidaria

• EX: coral, hydra, jellyfish, sea anemone• radial symmetry• incomplete digestive system (one opening)• no segmentation• no circulatory system • a circle of tentacles surrounds the mouth• have a cell structure called a nematocyst for

stinging prey

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Figure 23.8a  Jellyfish

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Figure 23.8b  Sea anemone

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Figure 23.8c  Coral polyps

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Figure 23.9  Two Stages of Life for Many Cnidarians

medusa

polyp

gastriccavity

gastriccavity

mouth

mouth

tentacles

tentacles

PHYLUM PLATYHELMINTHES = flatworms

• EX: planaria, flukes, tapeworms• bilateral symmetry• incomplete digestive system (one opening)• no segmentation• no circulatory system• concentration of sensory organs at anterior

“head” end

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Figure 23.12a  Flatworm anatomy

nerve cords

genitalpore

primitive eyes

cerebralganglia

penis testes ovaries

Flatworm anatomy

Nervous system includes primitive eyes and twocollections of nerve cells, the cerebral ganglia, that connect tonerve cords that run the length of the animal. In reproduction,Dugesia is hermaphroditic, meaning it possesses male sexorgans (testes and penis) as well as female sex organs (ovariesand other structures). When two Dugesia copulate, eachprojects its penis and inserts it in the genital pore of the other.

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Figure 23.11  Flatworms

PHYLUM NEMATODA = round worms

• Examples: Ascaris, Toxocara canis• bilateral symmetry• complete digestive system• no segmentation• no circulatory system• body is round in cross section• free living organisms or parasitic organisms

PHYLUM ANNELIDA = segmented worms

• EX: earthworm, clam worm, blood worm, leech

• bilateral symmetry• complete digestive system• segmentation - the body is composed of many

nearly identical segments • closed circulatory system

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Figure 23.13  The Body Plan of an Earthworm

anus

segments

coelomic space

muscular wallsbetween

segments

pairs of bristles

mouth “hearts”

intestine

brain

dorsalblood vessel

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Figure 23.14a  Hawaiian Christmas tree worm

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Figure 23.14b  Medicinal leech

PHYLUM MOLLUSCA - the mollusks

• bilateral symmetry• complete digestive system • no segmentation in adults• open circulatory system

PHYLUM MOLLUSCA - the mollusks

• EX: snails, slugs, clams, scallops, oysters, octopus, squid

• soft body. Some have a muscular foot used for movement

• a protective shell made of calcium carbonate sometimes covers the soft body. The shell does support the body somewhat, but is not a skeletal system

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Snail (Gastropod)

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Squid (Cephalopod)

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Scallop  (Bivalve)

PHYLUM ARTHROPODA arthropods

• EX: insects, spiders, ticks, scorpions, centipedes, millipedes, crustaceans (lobsters, crabs, etc.),

• the largest animal phylum• bilateral symmetry• complete digestive system• open circulatory system• exoskeleton

PHYLUM ARTHROPODA arthropods

• Segmentation – but many segments are fused into larger body regions (e.g., some of the 20 segments of an insect have fused together to form 3 body regions: head, thorax, and abdomen)

• many pairs of jointed appendages - arthropod means “jointed leg”

Class Insects

• Example: Beetles, flies, bees, grasshoppers

• largest group• 6 legs, 2 pair wings, 1 pair antennae

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 Insect Features

head thorax abdomen

segments

exoskeleton

muscles

joint

Class Crustaceans

• Example: Crabs, lobsters , shrimp, barnacles • 2 part body• gills• many appendages

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Crustacean Diversity

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Crustacean Diversity

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Crustacean Diversity

MANY BODY SEGMENTS AND APPENDAGE

Class Centipedes and Millipedes

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Class  Horseshoe crabs (most closely related to arachnids = spiders)

Class Arachnids

• Example: Spider, tick, scorpion• 8 legs, no wings, no antennae• Fang-like mouth parts

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Class Arachnid Diversity

PHYLUM ECHINODERMATA “spiny-skinned” animals

• EX: starfish, sea urchin, sea cucumber, sea lily, sand dollar

• radial symmetry in adults (the body is usually subdivided into five parts)

• complete digestive system • open circulatory system• no segmentation

PHYLUM ECHINODERMATA “spiny-skinned” animals

• endoskeleton made of calcified plates• tube feet use suction, to move and feed• rough skin has spines

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Figure 23.24a  Sea star

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Feather star. Related to sea lily. Has 10 arms, each of which branches many times.

PHYLUM CHORDATA - chordates

• EX: fish, birds, snakes, humans • bilateral symmetry• complete digestive system• modified segmentation - segmentation is

easily seen in the embryo but becomes somewhat hidden in the adult

• endoskeleton• closed circulatory system

PHYLUM CHORDATA - the chordates

Chordates have three unique characteristics:• notochord = hard supporting rod of the

skeleton along the back• nerve cord running with the notochord• pharyngeal gill slits - openings from inside the

pharynx to the environment. In fish, they contain gills which are respiratory organs.

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Three Universal Chordate Features

notochord

pharyngeal slits

dorsal nerve cord

The Vertebrate Classes:

• The Chordates are subdivided into three subphyla, but almost all species of chordate are within the Subphylum Vertebrata, the vertebrates.

• In the Vertebrata, the notochord is replaced during development by a new rod made of many pieces which is called the vertebral column or backbone.

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Subphylum Tunicates, a primitive chordate

3 CLASSES OF FISH

1. Jawless fish (e.g., lamprey) - 50 species2. Cartilaginous fish = fish with a skeleton of

cartilage (sharks, rays) - 800 species 3. Bony fish = fish with a skeleton of bone -

18,000 species

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Lamprey.  No Jaw, a Predator

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 Cartilaginous Fish. A ray

CLASS AMPHIBIA - amphibians

• EX: salamanders, frogs, toads • aquatic larvae with gills• adults with lungs• three chambered heart• Moist skin• no teeth, claws, or scales

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Figure 23.33  Amphibian Life Cycle

sperm

fertilizedegg

developing embryo

femalemale

immaturefrog

tadpole

maturefrog

egg

CLASS REPTILIA - reptiles

• EX: lizards, snakes, crocodiles, turtles • three chambered heart• dry skin covered with scales. (The shell of a

turtle is made of scales. The inner scales become bony and attach to the endoskeleton.)

• usually possess claws and teeth

CLASS AVES - birds

• Example: finch, blue bird• four chambered heart• warm blooded• skin covered with feathers• forelimbs adapted as wings• hollow bones - reduces the bird’s weight so

that flying is easier

CLASS MAMMALIA - mammals

• EX: kangaroo, mouse, bat, dog, cow, humans, fox, cat.• four chambered heart• warm blooded• skin covered with hair• modified sweat glands called mammary

glands to produce milk

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Mammal Diversity Plecental mammal, Bear

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Mammal Diversity Marsupial Kangaroo

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Mammal Diversity monotreme Duck-billed platypus