InvertebratesInvertebrates

By:Stephen

THIS IS A LINK

THIS IS A LINK TO INFORMATION ONBURGESS SHALE FOSSILS OF INVERTEBRATES

INVERTEBRATES EVOLVED DURING THE CAMBRIAN PERIOD –

FOSSIL – PRESERVED REMAINS OR EVIDENCE OF ANCIENT ORGANISMS

THIS IS A SCIENTIST WHO STUDIES FOSSILS

CLICK PICTURES OFINVERTEBRATE FOSSILS

SpongesPHYLUM: PORIFERA

PORE BEARING

No mouth, stomachs, or other organs

Most live in oceans Cannot move They stink a lot

Invertebrates with Stinging Cells

PHYLUM: CNIDARIANSTINGING CELLS

They have tentacles They have a mouth They live on the

ocean floor They shoot poisonous

darts

jellyfish

Sea anemonecoral

Worms They can grow back

parts if they lose parts.

Some worms can grow to 30 METERS long

An earthworm has hairs on it to help it go through the dirt!!!

Flatworm

Segmented

Roundworms

                                                             

PLATYHELMINTHES – FLAT WORMSNEMATODA – ROUND WORMANNELIDA – SEGMENTED WORMS

Invertebrates with Spiny SkinsPHYLUM: ECHINODERMATA

SPINY SKINNED

They have bodies with at least 5 sections

They have suction cup feet to walk They use tubes to catch food to.

Invertebrates with Soft BodiesPHYLUM: MOLLUSC

SOFT BODIED; MAY HAVE HARD OUTER SHELL

They live on land and fresh water and ocean water.

They make shells from minerals in the water

Two shelled mollusks (Bivalved = 2 shells) has a big foot to pull itself along

squid

snail

octopus

Snails have 1Shell- univalve

ArthropodsThis is the phylum name:

it means jointed appendages,segmented body; may undergo metamorphis; open circulatory

systemThere are 4 groups

C ru s tace a ns A ra ch n ids In se c ts C e ntip ed esM illip e d es

A rtho po ds

Arthopods

They have keen sense organs They have exoskeletons made out of

a complex carbohydrate called CHITIN

They have two or more segments

Crustaceans

They have five pairs of legs

They live near or on the ocean floor

Live on land and water

They have antennae

Arachnids

Spiders mites and ticks.

4 pairs of legs Most live on land. Some live in fresh

water They are called

parasites.

Insects

Largest group of arthropods

3 pairs of legs 3 main body part

sections 2 pairs of eyes Have mouths

Millipedes & Centipedes

Many body segments Live under rocks & dark

places Really have less than 100

legs Protects itself by curling up Millipedes have 4 legs on

each segment Centipedes have 2 legs on

each segment

millipede

centipede

TERMS TERMS ASSOCIATED WITH ASSOCIATED WITH

CHAPTER 29CHAPTER 29INVERTEBRATESINVERTEBRATES

SEGMENTS – IF AN ANIMAL HAS BILATERALSYMMETRY, IT IS SEGMENTED

SEGMENTS CAN MEAN A TYPE OF GASTRO-INTESTINAL MOTILITY (THIS WOULD REFERTO ALL WORMS, CNIDARIANS, ARTHROPODSTHAT HAVE SPECIALIZED ORGANS THAT DIGEST FOOD

SEGEMENTS CAN ALSO MEAN DIVISIONS OFTHE BODY – LIKE THE EARTHWORM HAS LINES;INSECTS HAVE A HEAD, THORAX &ABDOMEN

TRENDS IN THE EVOLUTION OF THE NERVOUS SYSTEM

1. CNIDARIANS HAVE THE SIMPLEST SYSTEM – A NERVE NET

2. FLAT WORMS AND ROUND WORMS HAVE NVERVE CELLS THAT ARE CENTRALIZED IN SOME, SMALL CLUMPS OF NERVE TISSUE, OR GANGLIA ARE FOUND IN THE HEAD

3. IN CEHALOPOD MOLLUSKS CAND ARTHROPODS, GANGLIA ARE ORGANIZED INTO A BRAIN THAT CONTROLS AND COORDINATES THE NEVEVOUS SYSTEM. THIS CONCENTRATION OF NERVE TISSUE AND ORGANS IN ONE END OF THE BODY IS CALLED CEPHALIZATION.

4. SPECIALIZATION IS THE THIRD TREND. IT IS COMPLEX. FLATOWORMS (PLATYHELMINTHES) HAVE EYE SPOTS WHICH CAN DETECT LIGHT. INSECTS CAN DETECT LIGHT, MOTION, COLOR, ETC

CNIDARIAN NERVE NET

ARTHROPOD – GANGLIA

MOLLUSK – BRAIN

CEPHALIZATION

1. Animals that reproduce sexually begin as a zygote2.The zygote undergoes divisions to form a blastula3.A blastula is a hollow ball of cells4.The blastula has 3 germ layers: a. Ectoderm---sense organs, nerves and skin b. Mesoderm---see slide number 21 - coelom c. Endoderm----digestive and respiratory systems

1. A COELOM IS A FLUID FILLED BODY CAVITY2. THE COELOM IS LINED FROM TISSUE3.MESODERM IS ONE OF THE GERM LAYERSOF THE EMBRYO.4.THE MESODERM IS THE MIDDLE LAYER OF THE EMBRYO5.THE MESODERM GIVES RISE TO MUSCLES, AND MUCH OF THE CIRCULATORY, REPRODUCTIVEAND EXCRETORY SYSTEMS

1. Flatworms are acoelomates (no true body cavity)2. Flatworm coelom is lined with tissue from endoderm;Thus it is not a true coelom3. Pseudocoeloms have a body cavity between the Endoderm and mesoderm tissues and it is partially linedWith mesoderm tissue – example: the Nematodes4. True coeloms – the body cavity is entirely made withTissues derived from the mesoderm. Examples: Annelids,Mollusks, Arthoropods and Echinoderms

FOOD IS DIGESTED WITHIN THE CELLS

FOOD IS BROKEN DOWN OUTSIDE THE CELL IN A DIGESTIVE CAVITY AND THEN ABSORBED INTO THE BODY

A ONE WAY SYSTEM HAS TWO OPENINGS: MOUTH AND ANUSTHIS ANIMAL USUALLY HAS SPECIALIZED REGIONS LIKE STOMACH/INTESTINES

TWO WAY DIGESTIVE SYSTEM

ONE OPENING SERVES AS AN ENTRANCE TO FOOD AND AN EXIT FOR WASTES

--FOOD IS DIGESTED BOTH INTRACELLULARLY AND EXTRACELLULARLY.--SOME CELLS OF THE GASTROVASCULAR CAVITY SECRETE ENZYMES AND ABSORB THE DIGESTED FOOD--OTHER CELLS SURROUND THE FOOD PARTICLES AND DIGEST THEM IN VACUOLES

PHYLUM INTRACELLULAR

EXTRACELLULAR

BOTH INTRA AND EXTRA

PORIFERA X - -

CNIDARIAN - - X

NEMATODA - X -

PLATYHELMINTES

- - X

ANNELIDA - X -

MOLLUSCA - X --

ARTHROPODA

- X -

ECHINODERM

- X -

TERMS YOU SHOULD NOW KNOW

NAMES OF PHYLUMS AND EXAMPLES CHARACTERISTICS OF ANIMALS CAMBRIAN PERIOD FOSSIL BURGESS SHALE PALEONTOLOGIST BILATERAL SYMMETRY RADIAL SYMMETRY DEUTEROSOME PROTOSOME BLASTULA BLASTOPORE GERM LAYERS OF EMBRYO ECTODERM MESODERM ENDODERM ZYGOTE FOSSIL Germ layers Ectoderm Mesoderm endoderm

SEGMENTATION CEPHALIZATION NERVE NET BRAIN GANGLION INTRACELLULAR DIGESTION EXTRACELLULAR DIGESTION GASTROVASCULAR CAVITY SESSILE MOTILE ENDOSKELETON EXOSKELETON CHITIN VACUOLE INVERTEBRATE VERTEBRATE THORAX SEGMENTS Coelom Acoelomate True coelom Coelom

RESPIRATORY ORGANS HAVE LARGESURFACE AREAS THAT ARE IN CONTRACT WITH AIR OR WATER. ALSO, FOR DIFFUSIONTO OCCUR THE RESPIRATORY SYSTEM \MUST BE MOIST

AQUATIC INVERTEBRATES- SPONGES, JELLYFISH, STAR FISH, SOME MOLLUSKS RESPIRETHROUGH THEIR SKIN.

SOME MOLLUSKS, ARTHROPODS AND MANYANNELIDS HAVE GILLS – FEATHERY STRUCTURESTHAT EXPOSE A LARGE SURFACE AREA TO THE WATER. GILLS ARE RICH IN BLOOD VESSELSTHAT BRING BLOOD CLOSE TO THE SURFACE FORGAS EXCHANGE

THE RESPIRATORY SYSTEMS ARE COVERED WITH MUCOUS OR WATER. THIS WATER, MUCOUS,PREVENTS WATER LOSS

THERE ARE SEVERAL TYPES OF RESPIRATORY SURFACES: 1.The mantle cavity of the snail is moist and it has an Extensive area lined with blood vessels2.The spider has book lungs – lungs that contain bloodVessels3.Insects have openings in the abdomen called spiracles.These spiracles lead to tracheal tubes where gases diffuse inAnd out.

INVERTEBRATES HAVE ONE OF THREE KINDS OFSKELETAL SYSTEMS: HYDROSTATIC SKELETONS,

ENDOSKELETONS, EXOSKELETONS

1. Hydrostatic – Annelids and certain Cnidarians are Hydrostatic – muscles surround a fluid filled body cavityThat supports the muscles. When the muscles contract, theyPush the fluid in the body cavity causing the body cavity toChange shape.2. Exoskeleton – hard outer covering made out of chitin. Arthropods move by bending and straightening muscles.Mollusks shells could be considered an exoskeleton3. Endoskeleton – inner skeleton; sea stars and other Echinoderms have inner calcified plates. The plates Function in support and protections

1. Animals reproduce sexually or asexually(Cnidarians can be asexual)2. Most of the other invertebrates are sexual)3. Gametes are the sex cells4. Zygote is the fertilized egg

5. EXTERNAL FERTILIZATION: Eggs are fertilized outside the body of the female6.INTERNAL FERTILIZATION: Eggs are Fertilized within the body of the female

7.HERMAPHRODITE – having both male and femaleSex organs. Annelids are hermaphrodites

MOST multicellular organisms must maintain a waterBalance in their tissues.MOST animals have an excretory system that rids the Body of metabolic wastes while controlling the amount of Water in the body

AQUATIC INVERTEBRATES- ammonia diffuses fromTheir body to the water outside. Flatworms (Platyhelminthes)Use a network of flame cells to eliminate excess waterTERRESTRIAL INVERTEBRATES- must conserve water.They convert ammonia into a compound called urea. Urea is released in urine.ANNELIDS AND MOLLUSKS – have nephridia (openingsCalled nephrostomes) that fluid enters and urine leaves throughExcretory spores.INSECTS have Malphigian Tubes – convert ammonia intoUric acid. Uric acid is a pasty substance – released through rectum

TERMS TERMS

HYDROSTATIC ENDOSKELETON

EXOSKELETON CHITIN

CEPHALIC CENTRAL NERVOUS SYSTEM

SEXUAL REPRODUCTION ASEXUAL REPRODUCTION

INTERNAL FERTILATION EXTERNAL FERTILIZATION

EXCRETION CIRCULATION

OPEN CIRC. SYSTEM CLOSED CIRC. SYSTEM

RESPIRATION GILLS

SURFACE AREA SPIRACLES

TRACHEAL TUBES INTERACELLULAR DIGESTION

EXTRACELLULAR DIGESTION

ONE WAY DIGESTIVE SYSTEM

TWO WAY DIGESTIVE SYSTEM

COELOM