Transcript Arthropods

PHYLUM ARTHROPODA
“JOINTED LEGS”
General Characteristics
• Largest phylum (75%
all animals)
• Terrestrial, Freshwater,
Saltwater
General Morphology
Exoskeleton: outside; made of chitin (protein, sequence of
amino acids)
1. Protection, attachment of muscles, support
2. Molt: Sheds exoskeleton as grows
3. Body segmented; bilateral symmetry
4. Jointed appendages
5. Dioecious – males are separate from females
Female
Male
6. Eyes – 2 types
Compound – image forming (mainly insects) many
eyes
Simple – detect movement
TYPES (Classes)
Insects - 750,000+ sp
• Rare in salt water; LOVE salt marshes (flies, mosquitoes)
Chelicerates – spiders, ticks, scorpions
• Horseshoe Crab- most primitive animal on Earth
• Soft bottom; shallow water; E. coast of N.
America only 1 species
Crustaceans – crab, shrimp, lobster
• Mostly saltwater
• Gills to get oxygen
• Appendages specialized for crawling, swimming,
mating, feeding
• 2 pairs sensory antennae