Arthropods 7 th Grade Life Science

3 Characteristics of all Arthropods Body Segments Jointed Legs Exoskeleton

Exoskeleton– hard outer covering that protects, covers and allows for muscle attachment.

4 Classes of Arthropods Insects Arachnids Centipedes and Millipedes Crustaceans

Insects Three Body Regions = Head, Thorax & Abdomen 3 pairs of legs on the thorax Breath through spiracles on the abdomen

Metamorphosis—change in shape (meta= change/ morph = shape) Incomplete metamorphosis—nymphs look more and more like adults Complete metamorphosis – larva undergo complete change to become an adult

Complete or Incomplete Metamorphosis??

4 Classes of Arthropods Insects Arachnids Centipedes and Millipedes Crustaceans

Arachnids Spiders Scorpions Mites and Ticks

4 Classes of Arthropods Insects Arachnids Centipedes and Millipedes Crustaceans

Centipedes and Millipedes Centipedes = predators Millipedes = herbivores

4 Classes of Arthropods Insects Arachnids Centipedes and Millipedes Crustaceans

Crayfish Crabs Shrimp Pill bugs

Crabs

Shrimp

Pill Bugs

Crayfish Kingdom –Animal Phylum – Arthropoda Class – Malacostraca Order – Decapoda Family – Cambaridae Genus -- Cambarus

Crayfish Anatomy Form = Function

Crayfish Circulatory System Open Circulatory System – Blood is carried from the heart in Arteries. Used blood pools and returns to the heart through ostia (no veins to return blood)

Crayfish Circulatory System Ostia -- Holes in the heart where blood re-enters to be pumped

Crayfish Respiratory System Gills-- are located at the side of the body Gills function to exchange Oxygen and Carbon Dioxide for Cellular Respiration.

Crayfish Respiratory System Gills-- are located at the side of the body Gills function to exchange Oxygen and Carbon Dioxide for Cellular Respiration.

Crayfish Digestive System 1.Mandible 2.Esophagus 3.2 Part Stomach 4.Intestine 5.Anus

Crayfish Digestive System Two-- Part Stomach

Crayfish Digestive System Cardiac Stomach – Stores Food

Teeth in stomach help to grind food

Crayfish Digestive System Pyloric Stomach – Digestion Occurs (digestive enzymes from digestive gland break down food )

Crayfish Digestive System Pyloric Stomach – pyloric muscles on the side of the pyloric stomach help grind food

Crayfish Digestive Glands – Produce digestive enzymes similar to our liver

Crayfish – Excretory System Anus-- excretes waste from intestine Green Glands – Filter waste out of the crayfish – work similar to our kidneys –Green glands secrete uric acid near the antennae.

Green Glands

The End