Phylum arthropoda characteristics
- 2. PHYLUM ARTHROPODA • Ex. Insects, crustaceans (crabs), arachnids (spiders), etc • Over 900 000 species • Found in every habitat on earth • Arthropods make up over 82% of all living things • 1018 arthropods living right now!
- 3. ARTHROPOD CHARACTERISTICS • Segmented body = Specialization • Head – Contains mouth parts, sense organs, antenna • Thorax – Attachment of appendages • Cephalothorax = head & thorax fused • Abdomen – Organs, few appendages
- 4. ARTHROPOD CHARACTERISTICS • Exoskeleton = Protection • Hard covering outside of ectoderm • Made from chitin (protein) • Protects organs • Prevents water loss (waxy cuticle) • Site of muscle attachment • Limits the size an arthropod can grow (heavy!) • Exoskeleton does not grow once it has formed – organism must molt and regrow skeleton to increase size
- 5. ARTHROPOD CHARACTERISTICS Jointed Appendages = Locomotion, feeding, reproduction • Uniramous (single branch) eg. Insects • Biramous (two branches) eg. Crustaceans
- 6. ARTHROPOD CHARACTERISTICS • Body Type: Bilateral Symmetry • Body Organization: Triploblastic (3 layers) • Body Cavity: Coelom (fluid filled cavity fully lined by mesoderm)
- 7. ARTHROPOD CHARACTERISTICS • Digestive System • Complete – Mouth and anus separate • Specialized by segmentation • Specialized mouthparts • Chelicera – Piercing, sucking or Mandible – Biting, chewing
- 9. ARTHROPOD CHARACTERISTICS • Excretory System • Anus • Malpighian Tubules (terrestrial) • Nitrogenous wastes crystalized and combined with feces • Conserve water • Green Gland (aquatic) • Concentrates nitrogenous wastes • Excreted nead base of antennae
- 11. ARTHROPOD CHARACTERISTICS Reproduction • Sexual – Dioecious • Internal fertilization (terrestrial, some aquatic) or external fertilization (some aquatic) • Asexual – Some species are able to regenerate lost limbs • Undergo metamorphosis • Complete: egg – larva – pupa – adult • Incomplete: egg – juvenile - adult
- 14. ARTHROPOD CHARACTERISTICS • Nervous System • Brain • Ventral nerve cord • Specialized sensory organs • Antenna • Compound eyes & ocelli • Olfactory organs
- 15. ARTHROPOD CHARACTERISTICS • Respiration • Aquatic - Gills • Terrestrial – Book lungs (arachnids) – Trachea/Spiracles (insects)
- 16. ARTHROPOD CHARACTERISTICS • Circulatory System • Open circulation – Blood pumped by heart to sinuses around tissues • Blue colour due to copper http://www.iflscience.com/plants-and-animals/how-horseshoe-crab- blood-saves-millions-lives
- 18. ARTHROPOD CHARACTERISTICS • Ecological Roles • Predators/Prey • Parasites/Vectors (lice, ticks, mosquitos) • Food source • Agricultural pests (locusts, catepillars, beetles, ) • Pollinators (bees, butterflies) • Produce honey, silk • Medical uses (bee pollen, crab blood)