Chapter 17

Remember….DKPCOFGS

Kingdom Animalia

General characteristics:– Heterotrophic– Locomotion– Multicellular – Life cycle where adult is diploid– Undergoes sexual reproduction and produce an

embryo

Animal DiversityInvertebrates– Lack an

endoskeleton of bone or cartilage

– All but one animal phylum are invertebrates

Vertebrates– Have an

endoskeleton of bone or cartilage

Type of Body Plan Sac-Plan– Incomplete digestive

system – Gastrovascular cavity

Tube-Within-a-Tube Plan– Complete digestive

system– Inner tube is digestive

system, outer tube is body wall

– Two openings

Digestive TractsIncomplete

One openingsame opening used to take in food and get

rid of wastesGVC

CompleteTwo openingsfood is ingested at one end wastes from digestion passed out of the

tract at the other end

Level of OrganizationCellular

Only composed of cellsSponges

TissueComposed of cells and tissuesJellyfish

OrganComposed of cells, tissues, and organsUs!

Type of Body CavityAcoelomate

– Lacks a body cavity– Tissues packed closely together

Pseudocoelomate– Body cavity incompletely lined

with mesoderm– fluid-filled cavity that contains

their organs– Organs are free within the cavity

and will move around easily when you manipulate them

Coelomate– Cavity that contains organs– Lined with mesoderm

Type of Symmetry Asymmetrical

– No particular symmetryRadial Symmetry

– Circular organization– can be bisected in any plane to produce mirror images– Sessile

Bilateral Symmetry– Definite right and left halves– only a cut down the midline will produce mirror images

Animal skeletonsCan be:

HydrostaticExternalInternal

ReproductionSexual reproduction

egg of one individual is fertilized by the sperm of anotherHermaphroditic animals

possess both male and female sex organsAsexual reproduction

single parent gives rise to an offspring that will be genetically identical to the parent

Asexual reproduction of a body part!!Fertilization /Copulation

Internal fertilizationExternal fertilization

Development of a fetus Internal External

Sponges

SpongesPhylum PoriferaSaclike body with many poresMainly aquatic animals Filter feedersAsexual and Sexual Reproduction– Hermaphroditic– Usually not self-fertilizing

Spicules– For internal support (endoskeleton)

Cnidarians

Cnidarians: True Tissues

Phylum Cnidaria

Tubular or bell-shaped with radial symmetry

All aquatic, mostly marine

Cnidarians

Cnidocytes– Stinging cells unique

to cnidariansTwo body types– Polyps and medusan

Gastrovascular cavity– Sac-like body plan

Cnidarians

Hydra – Freshwater– sac-like body plan with a

single opening– Digestion begins in

gastrovascular cavity, completed in cells

– Can reproduce sexually and asexually (budding)

Flatworms

Flatworms

Phylum Platyhelminthes

Planarians

– Found in lakes, ponds, and streams

– Reproduce both asexually and sexually Regeneration (asexual) Hermaphroditic (sexual)

– Reciprocal transfer – simultaneous transfer of the sperm to the genital orifice of the partner

Flatworms

Parasitic Flatworms– Tapeworms

Endoparasites Range in length from several millimeters to 20

meters Tough integument to protect from host’s enzymes Scolex

Roundworms

Roundworms: Phylum Nematoda– Tube within a tube body plan

Mouth and anus

– Hydrostatic skeleton

– Nonsegmented

– Some roundworms are free-living, others are parasitic

Roundworms: PseudocoelomatesAscaris– Move with whip-like motion– Females are much longer than males and

highly prolific– Eggs enter host in uncooked vegetables, soil,

or feces

CoelomatesThe rest of the species that we will study

are Coelomates

– Bilateral symmetry

– Organ level of organization

– Tube-within-a-tube body plan

Molluscs

MolluscsSecond largest animal phylum

Unique characteristics of molluscs

– Three distinct parts Visceral mass Foot Mantle

– Radula Grasping organ for feeding

Molluscs

Gastropods– Nudibranchs, conchs, and snails

Foot is flattened ventrally Aquatic gastropods have gills Terrestrial gastropods

– Mantle has lung-like function

MolluscsCephalopods

– Squid, octopus, chambered nautilus Foot has evolved into

tentacles Built for speed!!

Extremely well-developed eyes– Complex behaviors

Ink glands– Secrete “ink” as defense

mechanism

MolluscsBivalves– Clams, oysters, scallops

Two-part shells (valves) Filter-feeders

– Water enters through incurrent siphon

Annelids

Annelids: Segmented Worms

Phylum Annelida– Segmentation– Hydrostatic

skeleton– Tube-within-a-tube

body plan

Annelids: Segmented Worms

Oligochetes (Earthworms)– Locomotion

Contraction of longitudinal and circular muscles

Few setae per segment

– Gas exchange is across the body wall

Annelids: Segmented Worms

Oligochetes (Earthworms)– Reproduction

Hermaphroditic Worms lie parallel in opposite

directions– Clitellum produces mucus to keep

sperm moist After separation, produces a

slime tube Moves eggs and sperm together

for fertilization Slime tube then produces a

cocoon

Annelids: Segmented WormsLeeches

– Most live in freshwater

– Most are ectoparasites - have suckers for

feeding

– Have same general body plan as other annelids Lack setae

Each body ring has transverse grooves

Arthropods

Arthropods: Jointed AppendagesPhylum Arthropoda– Over 1 million species have been described

30 million may exist (mostly insects)

– Appendages are for: Walking, swimming, reproduction, eating, sensory

reception

– Exoskeleton of chitin (must molt to grow)– Well-developed nervous system

Brain and ventral nerve cord Sense organs

Arthropods: Jointed Appendages

Crustaceans– Barnacles, shrimps,

lobsters, and crabs (marine)– Crayfish (freshwater)– Sowbugs (terrestrial)– Known for their hard shells– Usual anatomy is a pair of

compound eyes and five pairs of appendages Front two pairs have sensory

functions Other three pairs are used in

feeding

Arthropods: Jointed AppendagesInsects– Three body regions

Head– Sensory antennae, eyes– Mouthparts are adapted to

each insect’s way of life Thorax

– Three pairs of legs and the wings

Abdomen– Contains most internal

organs

Comparison of Crayfish and Grasshopper Crayfish– Gills– Excrete liquid

nitrogenous wastes (ammonia)

– No reception of sound– Utilize uropods when

swimming

Grasshoppers– Spiracles and trachae– Grasshoppers excrete

solid wastes (uric acid)– Tympanum for

reception of sound– Have legs for hopping

and wings for flying

Arachnids: 6 pairs of appendagesScorpions

– Oldest terrestrial arthropods

– Abdomen ends with a venomous stingerTicks and Mites

– Parasites Transmit diseases such as Rocky Mountain spotted

fever or Lyme diseaseSpiders

– Spiders have a narrow waist that separates cephalothorax from abdomen Chelicerae have fangs that deliver poison to prey Silk glands for web-spinning

http://www.youtube.com/watch?v=0LmyyXcE6rw

http://www.youtube.com/watch?v=kdVvoSP8QtY

Millipedes and CentipedesMillipedes:

Eat decaying plant matter two pairs of short legs per body

segmentCentipedes:

terrestrial carnivores with poison claws

Have one pair of short legs per body segment

Echinoderms

EchinodermsCharacteristics of

Echinoderms– Marine animals– Endoskeleton

made of calcium-rich plates

– Spines stick out of their skin

– Adults exhibit radial symmetry

EchinodermsSea Stars– Found along shorelines on rocky surfaces– Five-rayed body with mouth on underside and

anus on upper side– Structures project through skin

Spines for protection Skin gills

– Extensions of skin for gas exchange

Chordates

Chordates Must exhibit these

characteristics:– Notochord– Dorsal tubular nerve

cord– Pharyngeal pouches– Postanal tail

The Chordates………Invertebrate chordates– Tunicates and lancelets

Vertebrate chordates– Fishes

– Amphibians

– Reptiles

– Birds

– Mammals

Nonvertebrate Chordates Tunicates (sea squirts)

– Squirt water when their siphons are disturbed

Live in ocean and are filter-feeders

Larva is bilaterally symmetrical and has four chordate characteristics

Adults are sessile, thick-walled, sac-like organisms

– The only chordate characteristics in the adults are pharynx and gill slits

Vertebrates Characteristics – Have four chordate

characteristics at some point in life

– Distinguishing features Strong, jointed endoskeleton Vertebral column composed

of vertebrae Efficient respiration and

excretion

Fishes Fishes: First Jaws, Then Lungs

Adapted to life in water– Sperm and eggs released into water– Fertilization external– Zygote develops into swimming

larval form

Fish vs Fishes???2 chambered heartEctothermicWhat are fish?– Jellyfish?– Starfish?– Crayfish?– Shellfish?

FishesThree main groups/Classes

of fishes– Jawless fishes– Cartilaginous fishes– Bony fishes

http://www.youtube.com/watch?v=O2FInaOCqoo

Amphibians Jointed appendages Class Amphibia– “two lives”– Tetrapods – Eyelids keep eyes moist– Have ears – Larynx for vocalization– Small lungs present in

adults Gas exchange also occurs

across moist skin– Three-chambered heartEctothermicLarge mouths and

consume prey whole

AmphibiansHave either internal or external fertilizationMetamorphic life cycle– Aquatic larva (gills) - water– Terrestrial adult (lungs) - land

Class AmphibiaOrder: Gymnophiona

Caecilians Order: Caudata

Salamanders and Newts

Order: AnuraFrogs and toads

http://www.youtube.com/watch?v=wXqK5QulbJ8

ReptilesAmniotic eggClass Reptilia– Body is covered with

scales– EctothermicEctothermic– Three chambered Three chambered

heart****heart****– EyelidsEyelids

ReptilesAmniotes

Tetrapods that have a terrestrially adapted eggAmniotic egg usually buried in substrate Contains membranes that protect the embryoIn reptiles, internal fertilization

http://www.youtube.com/watch?v=q7CQInAXoqY&feature=related

Class Reptilia – 4 OrdersOrder: Testudines– Turtles and tortoises

Order: Crocodilia– Crocodilians

Order: Rhynchocephalia– Tuataras

http://dsc.discovery.com/videos/crocodile-feeding-frenzy-alligator-egg-hunt.html

http://www.metacafe.com/watch/198880/weird_nature/

Class Reptilia – 4 OrdersOrder: Squamata – SO: Lacertilia

Lizards 4 limbs and tail

– SO: Serpentes Snakes Limbless

– SO: Amphisbaenia Amphisbaenians Short tails Scales in rings Limbless Subterranean

http://www.youtube.com/watch?v=rwRdqkEcmbs

http://www.youtube.com/watch?v=Unzg7C1KJo0

BirdsClass: AvesAmniote egg with a hard

shellInternal fertilization,

external incubation– Forelimbs are modified as wings– Bones are laced with air cavities– A beak has replaced jaws– Large sternum for attachment of

flight muscles– Air sacs to increase the efficiency

of breathing– Endothermic– Four-chambered heart– Cloaca

Mammals Class: Mammaliabody hair and milk-

producing mammary glands

Adapted for active life on land

Limbs that allow rapid movement

Four-chambered heartEndothermicHigh level of care for the

youngInternal development

(most)

Mammals Monotremes– Have a cloaca – Egg-laying mammals – Spiny anteater and

duck-billed platypus Both found in Australia

– Both males and females have modified sweat glands and secrete milk onto body surface

MammalsMarsupials– Begin development

within female’s body born very immature development is completed

within a pouch Attach to nipples of

mammary glands within the pouch

– Virginia opposum is the only marsupial species north of Mexico

– Mainly found in Australia

Mammals Placental Mammals–Extraembryonic membranes are modified for internal development

How primates differ from most mammals :

Most are adapted for living in treesLimbs are mobile, hands and feet have digitsOpposable thumbs (sometimes big toes)Eyes in the front of the headLarge, complex brainGenerally give birth to one offspring at a time– Extended period of juvenile dependency