Animalia

Animals Animals are spilt into two major groups: Invertebrates

Invertebrates These are animals without a backbone There are eight invertebrate phyla Porifera Cnidaria Platyhelminthes Nematoda Mollusca Annelida Echinodermata Arthropoda

Radial symmetry

Phylum Porifera Have bodies made of loosely joined cells No organs Some specialised cells Are a link between unicellularity and multicellularity Are sessile Asymmetrical

Phylum Cnidaria Have thin sack like bodies Have tentacles and nematocysts Can excrete a chitinous or calcium carbonate skeleton Exist in two forms: Medusa Polyp Includes: Corals Jellyfish

Phylum Platyhelminthes Have flat worm-like bodies Have a blind gut Many are parasites Includes: Planaria Liver flukes Tape worms

Phylum Nematoda Have long thin round worm like bodies Have bodies with no segments True guts Complex protective cuticle Are ubiquitous Many are parasitic

Phylum Mollusca Crawl on a single fleshy pad. Can have an internal or external shell Have a complete digestive system Includes: Snails & slugs Octopus & squid Scallops, clams and mussels Tusk & conch shells Limpets & chitons

Phylum Annelida Have round worm-like bodies Have bodies divided into segments Have true guts Include: Earthworms Beach/sand worms Spiny/bristle worms leeches

Phylum Echinodermata Have bodies divided into five parts Have spiny outer covering Have a true gut Often possess tubular feet system Are all marine Include: Starfish Sea urchins Brittle stars Feather stars Sand dollars Sea lillies Sea cucumbers

Phylum Arthropoda Have multiple pairs of legs and segmented bodies. Mostly bilaterally symmetrical Complete gut External chitinous skeleton Bodies divided into two or three segments Are ubiquitous There are three subphyla of arthropods: Chelicerata Crustacea Uniramia

Arthropods - chelicerata Usually have four pairs of legs. Have bodies divided into two sections May have fangs but are not for chewing, only injecting venom Includes: Horseshoe crabs Spiders, mites, ticks and scorpions (arachnids) Sea spiders

Arthropods - Crustacea Two pairs of antennae Have five-seven pairs of legs Biramous limbs (two parts) First pair often used as pincers Bodies covered in shell Mostly aquatic Includes: Lobsters, Crabs, Prawns, Shrimp Woodlice, sea lice Barnacles

Arthropods – Uniramia Includes insects, centipedes and millipedes Have three body parts Centipedes and millipedes have long thin bodies and pairs of legs on each of their many body sections

Arthropods - Insects Have three pairs of legs Bodies divided into three sections Often have wings