Classifying animals

Classifying organisms, from the Animal Kingdom according to the

principals of taxonomy

Thinker…

• Why is it thought that prokaryotic cells are more primitive than eukaryotic cells?

What Kingdom do I belong to?

• I am Prokaryotic.• I can live almost

anywhere.• I reproduce asexually.• I usually have a cell

wall.• I am heterotrophic

(eat food) or autotrophic (make my own food.)

Eubacteria

Plantae

• I am multicellular• I have a cell wall• I make my own food

(autotroph)

Protista

• I might be prokaryotic or eukaryotic

• I live in moist habitats • I can make my own

food but some of my friends have to consume their food

• I can be plant-like or animal-like

• I can make you sick

Fungi

• I am a heterotroph• I am sometimes

confused with a plant• I am usually

multicellular• I reproduce using

spores

Archaebacteria

• I am prokaryotic• I live in harsh

conditions (salt lakes, hot springs and animal guts)

• I am a heterotroph• I do have a cell wall,

but it is different from my cousins the Eubacteria

Animalia

• I am multicellular• I usually reproduce

sexually• My cells don’t have

walls• I can fly, swim, walk

or run

Classifying animals•There are six commonly recognized Kingdoms

– Eubacteria, Archaebacteria, Protista, Fungi, Plantae and Animalia

The animal kingdom can be split, further, into two main groups:

• animals with backbones (vertebrates)• animals without backbones (invertebrates).

8Da

Phylum

• There are about 30 phyla in the animal kingdom.

• All but one of these phyla are invertebrates

• We belong to the one phyla that has vertebrates (Phylum Chordata)

Characteristics of all Animals

• Heterotrophic, multicellular eukaryotes.

• Cells lack cell walls.

• Specialized tissue: nervous & muscle tissue.

• Primarily sexual reproduction.

The Invertebrates…

• Can you think of what organisms might be included in the invertebrate group???

• Of the approximately 30 phylum of invertebrates there are 5 you should know…

Invertebrates(5 main phylum)

molluscsarthropods

Annelida (segmented worms

echinodermscnidarians

jellyfish

8Da

Phylum Cnidaria

• Exhibits radial symmetry.

• Cells organized into tissues.

• E.g., hydrozoans, jellyfish, sea anemones, sea fans and corals.

Phylum Cnidaria

Two Main Cell Layers

1. • Covers outer body surfaces.• Some have muscle fibers or nerve nets.

2. • Covers inner body surfaces.

** Mesoglea:• A jelly-like layer between ectoderm and

gastroderm.

Ectoderm

Endoderm

Phylum Cnidaria

• All cnidarians have stinging structures within their tentacles.• Toxic substances paralyze prey.

• Mouth/anus leads to gastrovascular cavity.• Where digestion, circulation and gas

exchange occur.

Phylum Cnidaria

• Lifecycle alternates between asexual sessile polyps and sexual free-swimming medusas.

Phylum Cnidaria

Portuguese Man-of-War

• Tentacles may be up to 55 m in length.

Annelida and Mollusca

Body Plan• Exhibits bilateral symmetry.

• Each half is a mirror image of the other.• Dorsal: • Ventral: FRONT

BACK

Body Plan• Cephalization (Position of nervous

structures).• Sense organs and nerve cells concentrate at

anterior end.• Bilaterally symmetrical animals move through

environment with anterior end forward.

• Coelom (fluid-filled body

cavity).

EctodermMesodermCoelom

Endoderm

Phylum Annelida“Segmented Worms”

• Live in marine, freshwater and terrestrial environments.

• Segmented bodies and a coelom.

• Segmentation allows for larger growth and enhanced locomotion.

•

•

Phylum Mollusca

“Animals with a Shell”

• Includes snails, slugs, clams, squids and octopuses.

• Moist, muscular body without a skeleton.

All Mollusks

• Have a…– Complete digestive tract– Body cavity (coelom)– Bilateral symmetry for at least part

of their lives

• They have primitive brains and can sense their environment using sense organs located on top of their head.

Phylum MolluscaBody Plan

1. • Locomotion and feeding.

2. • Tissue that covers gills and secretes

shell.

3. • Internal Organs.

Muscular Foot

Mantle

Visceral mass

Phylum Mollusca

Class Bivalva

• Includes clams, oysters, scallops, mussels and other shellfish.

• Flexible hinge connects two shells.

• Have no head

• They don’t move much

• Filter feed

Phylum Mollusca

Class Gastropoda

• Includes snails and slugs.

• Use foot for locomotion.

• Respiration through gills and moist skin.

•

          

                    

          

                    

                              

Name means “stomach footed”

Phylum Mollusca

Class Cephalopoda• Includes squids, octopuses and

nautilus.• Shell reduced to an internal rod.

– Improves movement.• Cephalopoda means ‘head

footed’• Most complex mollusks• Arms with suckers• Sexual reproduction

Phylum Echinodermata

“Radially Symmetrical Marine Animals”• Includes sea stars, sea urchins, sand dollars

and sea cucumbers.• Larvae:• Adults:

• Have an endoskeleton (internal skeleton) with spiny projections.

• Water vascular system:

Bilateral Symmetry

Radial Symmetry (5 similar body segments = pentamerous)

Phylum Echinodermata

Phylum Arthropoda

“Animals with an Exoskeleton”

• 1, 170, 000 species (mostly insects).

• Segmented bodies, exoskeleton (external skeleton), jointed legs and blood cavity.

• Exoskeleton composed of chitin:• • •

Non-Living Material

Jointed AppendagesOutside skeleton protects muscles, organs and blood vessels.

Joint-Legged Animals

Phylum Arthropoda

• As arthropods grow, they molt or shed exoskeleton and grow a new one.

• • Gills evolved in aquatic arthropods.• Tracheae developed in terrestrial arthropods.

• • Open circulatory system.• Blood cavity directly bathes internal organs.

Respiration

Circulation

• Nervous System: Simple to complex

• Digestive System made of three parts:– Foregut – mouth to esophagus– Midgut - stomach– Hindgut – intestine to anus

• Reproduction:Sexual

Phylum Arthropoda

Class Arachnida

• Includes scorpions, spiders, mites and ticks.

• Cephalothorax: head fuses to thorax.

• 6 pairs of legs

Phylum ArthropodaClass Crustacea• Includes shrimp, lobsters, crayfish and

crabs.• Three body segments:

• Head, Thorax and Abdomen

• Paired appendages attach to each segment.• Two pair of antennae• Three pair of feeding appendages

• Respiration: Gills

Phylum Arthropoda

Class Insecta• 1.5 million species.• Three body segments:

• Head, Thorax and Abdomen

• Antennae on head sense environment.• Three pairs of walking legs on thorax.• May be one or two pairs of wings• Respiration:

• Air sacs and trachea that extend from external openings to tissues.

Phylum Arthropoda

• Flying Insects: Two pairs of stiff wings attached to thorax.

• Flies: One pair of wings.

• Beetles: Front wings form hardened wing covers.

Phylum Arthropoda

Your Work…• For each phylum we have learnt about,

describe how there structure is adapted to its habitat (Hint: pg 416, 427, 441)

• What main characteristics are used to classify animals into different phyla?

• Turn to pg 441. Do the classifying Invertebrates activity.

• Turn to pg 445. Do question 25

• Tomorrow we will be in RM 514