TOPIC 7

ANIMAL DIVERSITY

I. CHARACTERISTICS OF KINGDOM ANIMALIA

II. OVERVIEW OF ORIGINS & DIVERSITY

III. BODY PLANS & RELATIONSHIPS

A. PRESENCE OF TISSUES

B. BODY SYMMETRY

C. DEVELOPMENTAL PATTERNS &GERM LAYERS

D. PRESENCE & NATURE OF COELOM (BODY CAVITY)

IV. CHORDATE EVOLUTION

A. INVERTEBRATE CHORDATES

B. VERTEBRATES: ORIGINS OF MAJOR FEATURES

 

I. CHARACTERISTICS OF KINGDOM

A. MULTICELLULAR, DIPLOID ORGANISMS

B. HETEROTROPHS THAT FEED VIA INGESTION

C. NO CELL WALLS

D. STORE ENERGY AS GLYCOGEN

E. COLLAGEN

F. DISTINCTIVE INTERCELLULAR CONNECTIONS

G. EXCITABLE TISSUES

 

9 MAJOR ANIMAL PHYLA

PORIFERA: SPONGES

9,000 species

 

CNIDARIA: JELLYFISH, CORAL, ANEMONES

10,000 species

 

PLATYHELMINTHES: FLATWORMS, FLUKES, TAPEWORMS

20,000 species

 

NEMATODA: ROUNDWORMS

100,000 species

 

MOLLUSCA: SNAILS, CLAMS, SQUIDS

50,000 species

 

ANNELIDA: SEMENTED WORMS

15,000 species

 

ARTHROPODA: INSECTS, ARACHNIDS, CRUSTACEANS

1,000,000 species

 

ECHINODERMATA: SEA STARS, URCHINS, CUCUMBERS

7,000 species

 

CHORDATA: TUNICATES, LANCLETS, VERTEBRATES

40,000 species

 

(PLUS 25 TO 28 MINOR PHYLA)

III. BODY PLANS

A. PRESENCE OF TISSUES

1. TRUE TISSUE PRESENT:

EUMETAZOA

2. TRUE TISSUE ABSENT:

PARAZOA

= CELLULAR GRADE OF ORGANIZATION

PHYLUM PORIFERA

CHOANOCYTE CELLS

POROCYTE CELLS

AMOEBOCYTE CELLS

FILTER FEEDERS

INTERNAL "SKELETON" OFSPICULES OR FIBERS

(Si, Ca, or Proteins)

 

III. BODY PLANS

B. BODY SYMMETRY

1. RADIAL SYMMETRY: RADIATA

ORAL & ABORAL SURFACE

( = TOP & BOTTOM)

WHEEL - LIKE

USUALLY PLANKTONIC OR SESSILE

PHYLUM CNIDARIA

2. BILATERAL SYMMERTY: BILATERIA

DORSAL & VENTRAL SURFACE

( = TOP & BOTTOM)

LEFT & RIGHT

ANTERIOR & POSTERIOR END

CEPHALIZATION

USUALLY ACTIVE

REMAINING EUMETAZOA

 

III. BODY PLANS

C. DEVELOPMENT & GERM LAYERS

1. EMBRYO DEVELOPMENT

a. BLASTULA

HOLLOW BALL OF CELLS

b. GASTRULA

TWO-LAYERED, CUP-SHAPED EMBRYO

FORMED VIA GASTRULATION

INWARD MIGRATION OF CELLS

RESULTS IN 2 GERM LAYERS

c. ECTODERM

OUTER GERM LAYER

GENERALLY GIVES RISE TO "SKIN"

CAN GIVE RISE TO NERVOUS SYSTEM

d. ENDODERM

INNER GERM LAYER

LINES ARCHENTERON

= EMBRYONIC GUT

GIVES RISE TO DIGESTIVE TRACT

GIVES RISE TO ASSOCIATED ORGANS

LUNGS

LIVER & PANCREAS

 

III. BODY PLANS

C. DEVELOPMENT & GERM LAYERS

2. DIPLOBLASTIC ORGANISMS

2 BODY LAYERS

OUTER = EPIDERMIS

INNER = GASTRODERMIS

GUT = BLIND SAC

= GASTROVASCULAR CAVITY

RADIATA

3. TRIPLOBALSTIC ORGANISMS

3 GERM LAYERS

MESODERM = MIDDLE LAYER

GIVES RISE TO MUSCLE

ENDOSKELETON

CIRCULATORY SYSTEM

EXCRETORY ORGANS

BILATERIA

 

RADIATA

PHYLUM CNIDARIA

PHYLUM CTENOPHORA (COMB JELLIES)

 

FEATURES OF CNIDARIANS:

SINGLE GUT OPENING ENCIRCLED BY TENTACLES

MIDDLE ACELLULAR LAYER OF MESOGLEA

UNIQUE CELLS FOR FEEDING & DEFENSE

= CNIDOCYTES

MOVE USING CONTRACTILE FILAMENTS & A HYDROSTATIC SKELETON

POLYP (HYDROID) & MEDUSA (JELLYFISH) FORMS

 

3 CLASSES

HYDROZOA (ALTERNATE FORMS)

SCYPHOZOA (MAINLY MEDUSA)

ANTHOZOA (POLYP ONLY)

 

SOLITARY OR COLONIAL

MARINE OR FRESHWATER

 

III. BODY PLANS

D. PRESENCE & NATURE OF COELOM

1. COELOM

ENCLOSED BODY CAVITY

FLUID FILLED

BETWEEN GUT & BODY WALL

2. ACOELOMATES

MESODERM PRESENT

BODY CAVITY ABSENT

3. PSEUDOCOELOMATES

MESODERM PRESENT

BODY CAVITY PRESENT

BODY CAVITY NOT COMPLETELY LINED WITH MESODERM

4. [EU]COELOMATES

MESODERM PRESENT

BODY CAVITY PRESENT

BODY CAVITY LINED INSIDE & OUT WITH MESODERM

 

ACOELOMATES

PHYLUM PLATYHELMINTHES

BLIND GASTROVASCULAR CAVITY

DIVERSE MESODERMAL STRUCTURES

EXTENSIVE MUSCLE SYSTEM

SOLID BODY ACTS AS HYDROSTATIC SKELETON

PRIMITIVE EXCRETORY SYSTEM

LACK RESPIRATORY STRUCTURES

HERMAPHRODITES

 

4 CLASSES INCLUDE

TURBELLARIA: FREE-LIVING

EXAMPLE = PLANARIANS

TREMATODA: PARASITIC FLUKES

CESTODA: PARASITIC TAPEWORMS

 

PSEUDOCOELOMATES

PHYLUM NEMOTODA

PHYLUM ROTIFERA

3+ OTHER PHYLA

 

FEATURES OF NEMATODES

PSEUDOCOELOM USED AS HYDROSTATIC SKELETON

RIGID EXTERNAL CUTICLE

LONGITUDINAL MUSCLES ONLY

PSEUDOCOELOM USED FOR CIRCULATION

COMPLETE GUT

(MOUTH & ANUS)

SEPARATE SEXES

FREE-LIVING IN SOIL & SEDIMENTS

PARASITES OF PLANTS & ANIMALS

 

III. BODY PLANS

D. PRESENCE & NATURE OF COELOM

2 KINDS OF TRUE COELOMS

1. SCHIZOCOELOM

FORMS IN THE EMBRYO VIA SPLITTING OF A SOLID MASS OF MESODERM

FOUND IN PROTOSTOMES

2. ENTEROCOELOM

FORMS IN THE EMBRYO VIA OUTPOUCHING OF THE GUT

FOUND IN DEUTEROSTOMES

 

PROTOSTOMES

1. SPIRAL & DETERMINATE CLEAVAGE IN EMBRYO

2. MOUTH DEVELOPS FROM BLASTOPORE OF GASTRULA

3. SCHIZOCOELOUS BODY CAVITY

4. VENTRAL NERVE CORD

 

PHYLUM MOLLUSCA

PHYLUM ANNELIDA

PHYLUM ARTHROPODA

5+ MINOR PHYLA

 

DEUTEROSTOMES

1. RADIAL & INDETERMINATE CLEAVAGE IN EMBRYO

2. ANUS DEVELOPS FROM BLASTOPORE OF GASTRULA

3. ENTEROCOELOUS BODY CAVITY

4. DORSAL NERVE CORD

 

PHYLUM ECHINODERMATA

PHYLUM CHORDATA

2 MINOR PHYLA

 

PROTOSTOMES

PHYLUM MOLLUSCA CHARACTERISTICS

BODY UNSEGEMENTED

3 MAJOR BODY REGIONS

1. FOOT = LOCOMOTION

2. VISCERAL MASS = ORGANS

3. MANTLE = DORSAL TISSUE

SECRETES SHELL

ORIGINATED AS CREEPING, SCRAPING HERBIVORE WITH A RADULA

 

4 MAJOR CLASSES

POLYPLACOPHORA = CHITONS

GASTROPODA = SNAILS & SLUGS

BIVALVIA = CLAMS, OYSTERS, MUSSELS, SCALLOPS

CEPHALOPODA = SQUIDS, OCTOPUSES, NAUTILUS

 

PROTOSTOMES

PHYLUM ANNELIDA CHARACTERISTICS

BODY SEGEMENTED

REPEATED UNITS = METAMERES

USED AS HYDROSTATIC SKELETON FOR PERISTALTIC MOVEMENT

 

3 CLASSES

OLIGOCHAETA = "FEW SETAE"

TERRESTRIAL & FRESHWATER

POLYCHAETA = "MANY SETAE"

MARINE, BEAR PARAPODIA

HIRUDINEA = LEECHES

LACK SETAE, FRESHWATER

 

PROTOSTOMES

PHYLUM ARTHROPODA CHARACTERISTICS

BODY SEGEMENTED

SEGMENTS FORM FUNCTIONAL UNITS = TAGMATA

JOINTED APPENDAGES

SPECIALIZED IN FORM & FUNCTION

EXOSKELETON OF CHITIN

STRONG

FLEXIBLE

WATERPROOF

 

5 MAJOR CLASSES

ARACHNIDA = SPIDERS, SCORPIONS, MITES, TICKS

BODY UNITS = 1 OR 2 TAGMATA

MOUTH PARTS = CHELICERAE

4 PAIRS WALKING LEGS

LACK ANTENNAE

MAINLY TERRESTRIAL

 

DIPLOPODA = MILLIPEDES

HEAD PLUS MANY UNSPECIALIZED BODY UNITS

MOUTH PARTS = MANDIBLES

MANY WALKING LEGS (2 / SEGMENT)

1 PAIR ANTENNAE

TERRESTRIAL

 

CHILOPODA = CENTIPEDES

HEAD PLUS MANY UNSPECIALIZED BODY UNITS

MOUTH PARTS = MANDIBLES

MANY WALKING LEGS (1 / SEGMENT)

1 PAIR ANTENNAE

TERRESTRIAL

 

INSECTA = INSECTS

BODY UNITS = 3 TAGMATA

MOUTH PARTS = BASIC MANDIBLES OR MODIFIED FOR SUCKING, ETC.

3 PAIRS WALKING LEGS

1 PAIR ANTENNAE

WINGS ARE WIDESPREAD

TERRESTRIAL & FRESHWATER

 

CRUSTACEA = DECAPODS, COPEPODS, ISOPODS, AMPHIPODS, OSTRACODS, BARNACLES, CLADOCERANS

BODY UNITS = 2- 3 TAGMATA

MOUTH PARTS = MANDIBLES

3 OR MORE PAIRS OF LEGS

2 PAIRS OF ANTENNAE

MAINLY MARINE & FRESHWATER

 

PROTOSTOMES OR DEUTEROSTOMES?

LOPHORATE ANIMALS

3 PHYLA

5500 species

COLONIAL BRYOZOANS

PHORONID WORMS

BIVALVE-LIKE BRACHIOPODS

UNITED BY PRESENCE OF LOPHOPHORE ORGAN

= FEEDING STRUCTURE BEARING CILIATED TENTACLES

 

DEUTEROSTOMES

PHYLUM ECHINODERMATA

UNSEGMENTED

ANCESTORAL BILATERAL SYMMETRY REFLECTED IN LARVAE

SECONDARY RADIAL SYMMETRY IN ADULTS => FILTER FEEDERS

IN SOME BURROWING FORMS, ADULTS RETURNED TO BILATERAL SYMMETRY

UNIQUE WATER VASCULAR SYSTEM

= FLUID FILLED CANALS ENDING IN MUSCULAR TUBE FEET

USED IN FEEDING, GAS EXCHANGE & LOCOMOTION

ENDOSKELETON = PLATES OF CALCIUM CARBONATE

 

5 CLASSES (ALL MARINE)

CRINOIDEA = SEA LILIES

ASTEROIDEA = SEA STARS

OPHIUROIDEA = BRITTLE STARS

ECHINOIDEA = SEA URCHINS

HOLOTHUROIDEA = SEA CUCUMBERS

 

DEUTEROSTOMES

PHYLUM CHORDATA

4 MAJOR FEATURES OCCUR IN ALL CHORDATES AT SOME PHASE OF THE LIFE CYCLE

1. NOTOCHORD

1ST AXIAL ENDOSKELETON

DORSAL FLEXIBLE ROD

LOCOMOTION

 

2. DORSAL HOLLOW NERVE CORD

INFOLDING OF ECTODERM

PRECURSOR OF BRAIN & SPINAL CORD

COORDINATION

 

3. PHARYNGEAL SLITS

LATERAL OPENINGS IN THE FOREGUT

SUPPORTED BY CONNECTIVE TISSUE (ARCHES)

1ST FOR FILTER FEEDING, LATER FOR RESPIRATION

 

4. MUSCULAR POSTANAL TAIL

POSTERIOR EXTENSION OF NOTOCHORD & MUSCLE SEGMENTS

LOCOMOTION

 

DEUTEROSTOMES

PHYLUM CHORDATA

SUBPHYLUM UROCHORDATA

TUNICATES, SALPS, SEA SQUIRTS

MARINE

ADULTS SESSILE OR PLANKTONIC

FILTER FEEDERS WITH PHARYNGEAL BASKET

ACTIVE "TADPOLE" LARVAE DISPLAY CLASSIC CHORDATE FEATURES

LARVAE MAY HAVE GIVEN RISE TO OTHER CHORDATES THRU PAEDOGENESIS

 

DEUTEROSTOMES

PHYLUM CHORDATA

SUBPHYLUM CEPHALOCHORDATA

LANCELETS

MARINE

FILTER FEEDERS

BURROW IN SUBSTRATE

DISPLAY CLASSIC CHORDATE FEATURES IN ADULTS

NOTOCHORD EXTENDS INTO HEAD

 

DEUTEROSTOMES

PHYLUM CHORDATA

SUBPHYLUM VERTEBRATA

VERTEBRATES

APPEAR 520 mybp = MARINE

CLASSIC CHORDATE FEATURES SEEN ONLY IN EMBRYOS OF MANY SPECIES

CHARACTERIZED BY:

3-PART BRAIN

NEURAL CREST CELLS

CRANIUM (BRAIN CASE)

ENDOSKELETON OF BONE

VERTEBRAE (REPLACE NOTOCHORD)

 

MAJOR EVENTS IN VERTEBRATE EVOLUTION

520 mybp

1st KNOWN VERTEBRATES

= AGNATHA

 

460 mybp

EVOLUTION OF JAWS FROM ANTERIOR PHARYNGEAL ARCH = GNATHOSTOMATA

EVOLUTION OF PAIRED FINS

CHONDRICHTHYES

OSTEICHTHYES

RAY-FINNED FISHES

FLESHY-FINNED FISHES

 

MAJOR EVENTS IN VERTEBRATE EVOLUTION

360 mybp

INVASION OF LAND

EVOLUTION OF TERRESTRIAL LIMBS

LOSS OF GILLS & REFINEMENT OF LUNGS

= TETRAPODS (vs. PISCES)

AMPHIBIA

 

310 mybp

EVOLUTION OF TERRESTRIAL EGG WITH EXTRA-EMBRYONIC MEMBRANES

= AMNIOTES

SAUROPSIDS

ANAPSIDS

DIAPSIDS

SYNAPSIDS

GROUPS BASED ON SKULL FEATURES

 

TOPIC 7 - ANIMAL DIVERSITY

READINGS

INTRODUCTION TO CONCEPTS: PAGES 589 596

7 INVERTEBRATE PHYLA: PAGES 599 627

CHORDATES: PAGES 630 656

 

FIGURES:

32.1; 32.2; 32.3; 32.4; 32.5; 32.6; 32.7; 33.2; 33.3; 33.4; 33.5; 33.6; 33.7; 33.9;

33.10; 33.11; 33.12; 33.13; 33.15; 3.16; 33.17; 33.18; 33.21; 33.22; 33.23; 3.24;

33.25; 33.29; 33.30; 33.31; 33.23; 33.34; 33.35; 33.36; 33.37; 34.1; 34.2; 34.3;

34.5; 34.6; 34.8; 34.11; 34.13; 34.14; 34,17; 34.19; 41.9; 41.10; 42.2;

42.18; 42.21; 49.5, 49.23, 49.25

TABLES: 32.1; 33.1; 33.2; 33.3; 33.4; 33.5; 33.7; 34.1

 

GLOSSARY - TOPIC 7 - ANIMAL DIVERSITY, FORM & FUNCTION

Structure & Function:

Aboral, absorption, amniote, anterior, antennae, archenteron, bilateral symmetry, blastocoel, blastopore, blastula, cephalization, chelicerae, choanocyte, clevage, cnidocyte, coelom, complete gut, cranium, determinate clevage, diploblastic, dorsal, ectoderm, exoskeleton, endoderm, endoskeleton, enterocoelous, extracellular digestion, extra-embryonic membranea, filter feeder, foot, gastrovascular cavity, chitin, gas bladder, gastrula, gastrulation, germ layer, glycogen, hermaphrodite, hydrostatic skeleton, indeterminate clevage, ingestion, lophophore, mandibles, mantle, medusa, mesentery, mesoderm, nerve cord, neural crest cells, notochord, oral, paedogenesis, paired fins, peritoneum, pharyngeal slits, polyp, posterior, pseudocoelom, radial clevage, radial symmetry, radula, schizocoelous, segmentation, sessile, spicule, spiral clevage, tagmata, temporal fenestra, triploblastic, tube feet, ventral, vertebrae, visceral mass, water vascular system.

 

Taxonomic Terms:

Acoelomate, Agnatha, Amniote, Amphibia, Anapsid, Annelida, Anthozoa, Arachnida, Arthropoda, Asteroidea, Bilateria, Bivalvia, Cephalochordata, Cephalopoda, Cestoda, Chelicerata, Chilopoda, Chondrichthyes, Chordata, Cnidaria, Crustacea, Ctenophora, Coelomate, Deuterostome, Diapsid, Diplopoda, Echinodermata, Eumetazoa, Fleshy-finned Fish, Gastropoda, Gnathstomata, Hirudinea, Hydrozoa, Insecta, Mollusca, Nematoda, Oligochaeta, Osteichthyes, Parazoa, Pisces, Platyhelminthes, Polychaeta, Polyplacophora, Porifera, Protostome, Pseudocoelomate, Radiata, Ray-finned Fish, Rotifera, Sauropsids, Scyphozoa, Syanaspid, Trematoda, Trilobita, Turbellaria, Uniramia, Urochordata, Vertebrata.