Arthropods

Characteristics

Segmentation

More obvious in larval forms, adults have fused segments -----> Head | Thorax | Abdomen

Some have a fused head and thorax -- the cephalothorax

Taxonomy

taxonomy

Subphylum Chelicerata

spider

Subphylum Crustacea

 

Crayfish Dissection covers more on the Crayfish Anatomy

Subphylum Uniramia

- Insects and their Relatives

Includes 3 classes --- Chilopoda (centipedes), Diplopoda (millipedes), & Insecta

Class Chilopoda

millipede

Class Diplopoda

Class Insecta

 

Insect Life Cycle

Metamorphosis - dramatic physical change

Complete metamorphosis: Larva --> pupa ---> adult (example: butterflies)
Incomplete metamorphosis: Egg --> nymph --> adult (example: crickets)

grasshopper

metamorphosis

 

Social Insects: Honeybees (workers, queen, drones). Termites, some wasps

Queen: Lays eggs (1 queen per hive)
Drones: a few males to fertilize eggs
Workers: all infertile females