Phylum Arthropoda

Characteristics

• Most diverse and successful
• Have segmentation
• Exoskeleton of chitin
• Joined appendages
• Advanced nervous system
• Respiratory structures
• Complex muscular system

• Both segmented
• Specialized body regions
• Brain and central nerve cord
• Phylum Onicophora-velvet worms

Classification

Phylum Arthropoda

Subphylum Trilobita

Subphylum Chelicerata

Class Merostomata-Arachinda-Pycnogonida

Subphylum Mandibilata

Class Diplopoda-Crustacea-Insecta-Chilpoda

• Horseshoe crab-(g) Limulus polyphemus
• Carapace- unjointed exoskeleton
• Simple and compound eyes
• Telson- tail
• Book gills
• Most are extinct

• Spiders, scorpions, ticks, mites
• Chelicerae modified into fangs in spiders

Class Arachnida

Spiders

• Book lungs
• Predators-venom
• Silk glands- spinnerets
• Local fatal spiders--Black Widow/Brown Recluse

Class Arachnida

Mites

• Eat crops
• Infest animals
• Transmit disease
• Scabies-tunnel in skin
• Mange-Demodox, follicle mite

Class Arachnida

Ticks

•  Dermacenter(g)- Rocky Mountain Spotted Fever
• Zxodes-Lyme disease

Subphylum Mandibulata

Class Crustacea

• Crab, shrimp, lobster
• Daphnia-zooplankton
• Biramous appendages-primitive
• 2 pairs or antenni
• 5 pairs of walking legs
• Swimmerets for swimming/reproduction
• Uropod- tail

Subphylum Mandibiulata

Other Classes

• Unirmous appendages
• 1 pair of antennae

Subphylum Mandibulata

Class Insecta

• Entomology- study of insects
• Head, thorax, abdomen
• Spiracles and trachael tubes
• Malphigian tubes
• Heart with ostia
• Dioecious

Class Insecta

Development

• Direct- Juveniles like parent, typically wingless (silverfish)
• Incomplete- Nymph stages, wings (cicadas, mantids)
• Complete- holometabolous- complete change, pupa stage, 88% of insects

• Millipedes
• 2 legs per segment
• herbivorous
• Repungratorial glands- secrete toxin

• 1 leg per segment
• Carnivorous
• Venom in jaws

Phylum Echinodermata

Characteristics

• Pentaradial symmetry-evolved form biradial symmetry
• Endoskeleton amde of CaCO3-tests or ossicles
• Water vascular system
• Tube feet for feeding