Kingdom – Animalia Phylum Arthropoda – “jointed foot” Sub phyla: Crustacea – crabs, crawfish, shrimp ARTHROPODS

Kingdom – Animalia Phylum Arthropoda – “jointed foot” Sub phyla: Chelicerata – horseshoe crab, spiders ARTHROPODS

Kingdom – Animalia Phylum Arthropoda – “jointed foot” Sub phyla: Uniramia – insects, centipedes, millipedes ARTHROPODS

Kingdom – Animalia Phylum Arthropoda – “jointed foot” Sub phyla: Trilobita – ancestor of today’s arthropods extinct ARTHROPODS

Basic Characteristics 1.Segmented bodies divided into segments fused into 2 or 3 larger body regions

Basic Characteristics 1.Jointed appendages – for sensing, eating, reproduction, moving, defending

Basic Characteristics 1.Exoskeleton – outside skeleton 1.Made of chitin – type of carbohydrate 2.Hardened for protection 3.Limits the size because it has to molt to grow 2.Bilateral symmetry

BODY SYSTEMS Nervous system –Ventral nerve cord and brain –Has ganglia in each segment –Most have compound eyes Circulatory system –Open system – no vessels to enclose blood Respiratory system –Gills in aquatic animals –Tracheal tubes in terrestrial animals

CRUSTACEANS Body regions - –Cephalothorax – head and thorax are fused Most appendages are attached here Covered by a hardened shell of chitin (carapace) –Abdomen – long, narrow tail region Segmented Have swimmerets

CRUSTACEANS Body systems –Respiratory Feathery gills in the thorax – connected to walking legs to create water flow over the gills –Excretory Green gland located in the head extracts nitrogenous wastes from the blood and maintains proper water and ion amounts in the body –Reproductive Sexual Eggs are fertilized as they pass through the gonopore Swimmerets hold the fertilized eggs

CHELICERATES Body regions –Cephalothorax –Abdomen Do not have sensory antennae like other arthropods Most have simple eyes, not compound All have appendages called chelicerae –Modified pincers or fangs for killing prey Most are terrestrial except for the horseshoe crab Have simple and compound eyes Obtain oxygen through book gills Includes the Class Arachnida – spiders, mites & ticks

UNIRAMIANS Includes insects, centipedes and millipedes Have 3 body regions –Head –Thorax –Abdomen Have compound eyes Have malphigian tubules to excrete waste Have tracheal tubes for respiration

TRILOBITA Extinct ancestors to today’s arthropods