Invertebrates By:Stephen THIS IS A LINK

THIS IS A LINK TO INFORMATION ON BURGESS 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 OF INVERTEBRATE FOSSILS

Sponges PHYLUM: PORIFERA PORE BEARING  No mouth, stomachs, or other organs  Most live in oceans  Cannot move  They stink a lot

Invertebrates with Stinging Cells PHYLUM: CNIDARIAN STINGING CELLS  They have tentacles  They have a mouth  They live on the ocean floor  They shoot poisonous darts jellyfish Sea anemone coral

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 WORMS NEMATODA – ROUND WORM ANNELIDA – SEGMENTED WORMS

Invertebrates with Spiny Skins PHYLUM: 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 Bodies PHYLUM: 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 1 Shell- univalve

Arthropods This is the phylum name: it means jointed appendages, segmented body; may undergo metamorphis; open circulatory system There are 4 groups

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 ASSOCIATED WITH CHAPTER 29 INVERTEBRATES

SEGMENTS – IF AN ANIMAL HAS BILATERAL SYMMETRY, IT IS SEGMENTED SEGMENTS CAN MEAN A TYPE OF GASTRO- INTESTINAL MOTILITY (THIS WOULD REFER TO ALL WORMS, CNIDARIANS, ARTHROPODS THAT HAVE SPECIALIZED ORGANS THAT DIGEST FOOD SEGEMENTS CAN ALSO MEAN DIVISIONS OF THE 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 zygote 2.The zygote undergoes divisions to form a blastula 3.A blastula is a hollow ball of cells 4.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 CAVITY 2. THE COELOM IS LINED FROM TISSUE 3.MESODERM IS ONE OF THE GERM LAYERS OF THE EMBRYO. 4.THE MESODERM IS THE MIDDLE LAYER OF THE EMBRYO 5.THE MESODERM GIVES RISE TO MUSCLES, AND MUCH OF THE CIRCULATORY, REPRODUCTIVE AND 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 coelom 3.Pseudocoeloms have a body cavity between the Endoderm and mesoderm tissues and it is partially lined With mesoderm tissue – example: the Nematodes 4.True coeloms – the body cavity is entirely made with Tissues 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 ANUS THIS 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

PHYLUMINTRA CELLULAR EXTRA CELLULAR BOTH INTRA AND EXTRA PORIFERAX-- CNIDARIAN--X NEMATODA-X- PLATYHELMIN TES --X ANNELIDA-X- MOLLUSCA-X-- ARTHROPO DA -X- ECHINODER M -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 LARGE SURFACE AREAS THAT ARE IN CONTRACT WITH AIR OR WATER. ALSO, FOR DIFFUSION TO OCCUR THE RESPIRATORY SYSTEM \ MUST BE MOIST

AQUATIC INVERTEBRATES- SPONGES, JELLY FISH, STAR FISH, SOME MOLLUSKS RESPIRE THROUGH THEIR SKIN. SOME MOLLUSKS, ARTHROPODS AND MANY ANNELIDS HAVE GILLS – FEATHERY STRUCTURES THAT EXPOSE A LARGE SURFACE AREA TO THE WATER. GILLS ARE RICH IN BLOOD VESSELS THAT BRING BLOOD CLOSE TO THE SURFACE FOR GAS 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 vessels 2.The spider has book lungs – lungs that contain blood Vessels 3.Insects have openings in the abdomen called spiracles. These spiracles lead to tracheal tubes where gases diffuse in And out.

INVERTEBRATES HAVE ONE OF THREE KINDS OF SKELETAL SYSTEMS: HYDROSTATIC SKELETONS, ENDOSKELETONS, EXOSKELETONS 1.Hydrostatic – Annelids and certain Cnidarians are Hydrostatic – muscles surround a fluid filled body cavity That supports the muscles. When the muscles contract, they Push the fluid in the body cavity causing the body cavity to Change shape. 2.Exoskeleton – hard outer covering made out of chitin. Arthropods move by bending and straightening muscles. Mollusks shells could be considered an exoskeleton 3.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 cells 4. Zygote is the fertilized egg 5. EXTERNAL FERTILIZATION: Eggs are fertilized outside the body of the female 6.INTERNAL FERTILIZATION: Eggs are Fertilized within the body of the female 7.HERMAPHRODITE – having both male and female Sex organs. Annelids are hermaphrodites

MOST multicellular organisms must maintain a water Balance 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 from Their body to the water outside. Flatworms (Platyhelminthes) Use a network of flame cells to eliminate excess water TERRESTRIAL INVERTEBRATES- must conserve water. They convert ammonia into a compound called urea. Urea is released in urine. ANNELIDS AND MOLLUSKS – have nephridia (openings Called nephrostomes) that fluid enters and urine leaves through Excretory spores. INSECTS have Malphigian Tubes – convert ammonia into Uric acid. Uric acid is a pasty substance – released through rectum

TERMS HYDROSTATICENDOSKELETON EXOSKELETONCHITIN CEPHALICCENTRAL NERVOUS SYSTEM SEXUAL REPRODUCTIONASEXUAL REPRODUCTION INTERNAL FERTILATIONEXTERNAL FERTILIZATION EXCRETIONCIRCULATION OPEN CIRC. SYSTEMCLOSED CIRC. SYSTEM RESPIRATIONGILLS SURFACE AREASPIRACLES TRACHEAL TUBESINTERACELLULAR DIGESTION EXTRACELLULAR DIGESTION ONE WAY DIGESTIVE SYSTEM TWO WAY DIGESTIVE SYSTEM COELOM