Phylum Arthropoda

General Characteristics Arthropod = _______________ Largest group of animals 80% of described species 30-50 million species Most varied

General Characteristics Con’t Metamerism (body divided into segments) _____________________________ Paired, jointed appendages Ecdysis-molting (growth) Open Circulatory System Complete digestion tract

Metamerism (Body Segments)

General Characteristics Con’t Ventral Nervous System __________________ Metamorphosis 5 Subphylum Trilobitomorpha, Myriapoda, Chelicerata, Crustacea, Hexapoda

Functions of exoskeleton _______________ Minimize H2O loss Muscle attachment

Exoskeleton Structure Composed of _________________ Epicuticle: outer layer Water proof Procuticle: inner layer Made of chitin

Ecdysis (molting) _____________________________ 1. Enzymes digest old exoskeleton 2. New exoskeleton secreted New exoskeleton is soft 3. Scleratization (hardening)

Ecdysis (molting) Molting is important for arthropod growth Can’t grow in a suit of armor Is also a dangerous time for arthropods Typically animals about to molt, will go into hiding just before the process begins

_________________________ Changes in body form from larval to adult Ex. Butterfly, Dragonfly Reduces competition for food and living space

Subphylum Trilobitomorpha ___________________! All extinct and marine Body with 3 sections

Myriapoda- “many legs” Millipedes, centipedes Paired legs Subphylum Myriapoda Myriapoda- “many legs” Millipedes, centipedes Paired legs _______________________

Millipedes vs. Centipedes Herbivorous Appear to have 2 legs per segment _____________ Non-venomous

Have only 1 pair of legs per segment Faster Venomous Centipedes ____________ Have only 1 pair of legs per segment Faster Venomous

Subphylum Chelicerata Spiders, mites, ticks, scorpions, horseshoe crabs, Have chelicera- fangs ________________ Cephalothorax Abdommen

_______________ Appendages: 1st pair- chelicera: feeding (often fang-like) 2nd pair- Pedipalps: feeding, locomotion, reproduction

Subphylum Hexapoda INSECTS

General Characteristics Hexapoda = “____________” Includes the class Insecta 30 million species 27 Major orders We will only learn 8

General Characteristics Con’t 3 pairs of legs 6 total 1 pair of antennae Most have 2 pairs of wings ______________________ 3 part body plan Head, Thorax, Abdomen

Is a unique trait to the insects Insect Flight Is a unique trait to the insects Different insects have wing modifications for specific functions

Economic Importance Parasites Ticks, fleas Are considered agricultural pests. 1949-European corn borer caused $349 million in damage to the US corn crop

Economic Importance Con’t Provide goods Honey Beeswax Yummy (to certain cultures) Silk Dyes

Economic Importance Con’t Also are vectors for many diseases Bubonic plague (flea) Malaria (mosquito) _________________(mosquito) African Sleeping Sickness (Tsetse fly)

Subphylum Crustacea

General Characteristics Includes crabs, lobsters, crayfish, shrimp, and barnacles _____________________________ Biramous Appendage: branched Y-shaped appendages

General Characteristics Con’t ___________________ Marine and Freshwater 2 or 3 body segments Head, Thorax, and Abdomen OR Cephalothorax and Abdomen

Reproduction ______________ Few monoecious (hermaphroditc)

Females retain eggs until hatching

Tasty—people like to consume them _____________ Economic Importance Tasty—people like to consume them _____________

Ecological Importance Scavengers-eat dead material _______________(shrimps, barnacles)