Introduction to Animal Phyla Phyla Calcarea and Silicea

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Introduction to Animal Phyla

Introduction to Animal Phyla

Phyla Calcarea and Silicea • Sponges used to be classified in one Phylum =

Phyla Calcarea and Silicea • Sponges used to be classified in one Phylum = Porifera Pore-bearing • All aquatic • Have pores (ostia) that water flows through • Vary in size and shape – radial or asymmetrical

 • Cellular level of organization – no tissues • Multicellular: body a loose

• Cellular level of organization – no tissues • Multicellular: body a loose aggregation of cells • Intracellular digestion • Excretion and respiration by diffusion • Sessile adults • Asexual reproduction by buds or gemmules • Sexual reproduction – eggs and sperm • Free-swimming larvae

Phylum Cnidaria nettles • Includes: hydra, jellyfish, coral, sea anemones • All aquatic •

Phylum Cnidaria nettles • Includes: hydra, jellyfish, coral, sea anemones • All aquatic • Radial symmetry • Two body forms • Polyp: sessile (cannot move) • Medusa: free swimming • Tentacles with cnidocytes that contain stinging organelles called nematocytes

 • Diploblastic – two germ layers (endo- and ectoderm) with mesoglea • Gastrovascular

• Diploblastic – two germ layers (endo- and ectoderm) with mesoglea • Gastrovascular cavity; extracellular digestion • Nerve net and primitive muscular system • Asexual reproduction by budding • Sexual forms either monoecious or dioecious – planula larva

Phylum Platyhelminthes flat-worms • Cell-tissue level of organization – most systems incomplete or lacking

Phylum Platyhelminthes flat-worms • Cell-tissue level of organization – most systems incomplete or lacking • Body flattened dorsoventrally • Bilateral symmetry • Classes Monogenea Trematoda and Cestoda are entirely parasitic • Class Tubellaria – free-living

 • Triploblastic – three germ layers • Acoelomate – no body cavity between

• Triploblastic – three germ layers • Acoelomate – no body cavity between the mesoderm and endoderm • Sexual reproduction by gametes – most forms monoecious (separate sexes) • No asexual reproduction • Complex life cycles with multiple hosts in parasitic forms

Phylum Nematoda Thread • Roundworms • Organ-system level of organization • Body round slender

Phylum Nematoda Thread • Roundworms • Organ-system level of organization • Body round slender tubelike, tapered at both ends • Bilateral symmetry • Mostly free-living in soil or water; some parasitic forms (Ascaris)

 • Triploblastic – three germ layers • Pseudocoelomate – body cavity in between

• Triploblastic – three germ layers • Pseudocoelomate – body cavity in between the mesoderm and endoderm • Body covered with a secreted, flexible, nonliving cuticle • Sexual reproduction with gametes – dioecious (male and female forms) • No asexual reproduction

Phylum Annelida Little rings • • Segmented worms Bilateral symmetry • Two major classes

Phylum Annelida Little rings • • Segmented worms Bilateral symmetry • Two major classes 1. 2. Oligochaeta (earthworm) Hirudinea – – – Includes leeches Freshwater parasites Secrete enzyme to prevent blood clotting in host

Mollusks • • • Phylum = Mollusca Includes oysters, clams, snails and octopus Three

Mollusks • • • Phylum = Mollusca Includes oysters, clams, snails and octopus Three classes 1. Bivalvia – clams, two shells 2. Gastropoda – snails, single shell – Largest group – – Most advanced Mouth surrounded by tentacles 3. Cephalopoda – octopus, no shell

Echinoderms – spiny skin • Phylum Echinodermata includes starfish, sea urchins, sea cucumbers and

Echinoderms – spiny skin • Phylum Echinodermata includes starfish, sea urchins, sea cucumbers and sand dollars • Have internal skeletons that consists of calcified plates embedded in body wall • Radial symmetry • Spiny projections on plates stick through skin. • Have an oral and aboral surface

Phylum: Arthropoda • Most successful and abundant phylum of animals • 1 million known

Phylum: Arthropoda • Most successful and abundant phylum of animals • 1 million known species (400, 000 plants, 200, 000 all other animals)

5 classes of arthropods 1. 2. 3. 4. 5. Crustacea – lobsters etc. Chilopoda

5 classes of arthropods 1. 2. 3. 4. 5. Crustacea – lobsters etc. Chilopoda - centipedes Diplopoda - millipedes Arachnida - spiders Insecta - bugs

Common Features of all Arthropods 1. Jointed legs 2. Exoskeletons made of protein and

Common Features of all Arthropods 1. Jointed legs 2. Exoskeletons made of protein and chitin (hard and lightweight but must molt) 3. Segmented, most have: 1. Head 2. Thorax 3. Abdomen 4. Well developed nervous system 5. Open circulatory system

Centipedes • Class: Chilopoda • Poison claws on first segment • Body segments have

Centipedes • Class: Chilopoda • Poison claws on first segment • Body segments have one pair of legs • Feed on insects

Millipedes • Class: Diplopoda • Body segments have two pairs of legs • No

Millipedes • Class: Diplopoda • Body segments have two pairs of legs • No poison claws • Feed on decaying plants • May roll into ball or use “stink” glands when disturbed

Spiders, ticks, mites, scorpions • Class Arachnida • Most live on land resemble insects

Spiders, ticks, mites, scorpions • Class Arachnida • Most live on land resemble insects • Book lungs for gas exchange • Some have spinnerets for spinning silk (web) • 8 legs

Insects are successful because: • Only invertebrate that can fly • Tremendous variation and

Insects are successful because: • Only invertebrate that can fly • Tremendous variation and adaptations for feeding and reproduction, such as: • Mouthparts • Body form • Legs • High rate of reproduction and a short life cycle • Small

Metamorphosis • Distinct changes as an animal develops from an egg to an adult

Metamorphosis • Distinct changes as an animal develops from an egg to an adult • Incomplete (grasshoppers and crickets) eggs nymphs adult • Complete (moths, butterflies, beetles, bees) eggs larva pupa adult

Entomology – the study of insects • Bad: • Billions of dollars in damage

Entomology – the study of insects • Bad: • Billions of dollars in damage to crops • Transmit animal and plant diseases • Insecticide poisons the environment • Sting and bite • Good • Pollinate crops • Destroy harmful insects • Make honey and other products

Clam Dissection (pg 739) 1. 2. Find the valve adductor muscles. To open the

Clam Dissection (pg 739) 1. 2. Find the valve adductor muscles. To open the shell, you must CAREFULLY cut these muscles. Once open – make two drawings 1. 2. 3. Internal anatomy Draw before you cut it open Label 10 items total.

Crayfish Dissection 1. External anatomy – draw and label ten items 2. To open

Crayfish Dissection 1. External anatomy – draw and label ten items 2. To open crayfish you must remove the carapace: Most of the body organs are located in the cephalothorax, the abdomen is mostly muscle. Make cuts 1 cm on each side of the midline toward the eyes. Snip between the two cuts and remove the strip of carapace. 3. Internal anatomy – draw and label five to ten items 4. Look at any part of the crayfish with the dissection scope. Make a drawing and label what it is.

Grasshopper Dissection 1. 2. External Anatomy – draw and label 10 items To open

Grasshopper Dissection 1. 2. External Anatomy – draw and label 10 items To open grasshopper up: • 3. 4. Cut off the wings and legs. Carefully open the exoskeleton. Internal Anatomy – draw and label 5 items, is it male or female? Make third drawing using the dissection scope. Label what it is.