Arthropods

Why So Successful?Why So Abundant?

Why So Successful?Why So Abundant?

Fact: There are more than 1 million different species of arthropod

Fact: for every one human, there are 1 million arthropods on Earth

Exoskeleton

Strong Protective Flexible at the joints

Segmentation & Appendages

Variety of appendages ► efficient locomotion

Legs (walking, hopping, swimming)Wings (flying)

Segmentation & Appendages

Variety of mouth parts ►many feeding patterns

Respiration:Air Piped Directly to Cells

O2 direct to muscles ► spiracles to tracheae

permits rapid movement

Highly Developed Senses

Touch E.g. antennae, sensilla Smell / chemosensors Hearing / Vibration E.g. tympanae (# 11) Balance

Complex Behaviors

1. Insect Societies (division of labor)

2. Many innate behaviors (genetically programmed) permit survivalE.g. * weaving of

spider webs,* building of bee hives, * bee dances

Bee dances

Dance performed in hive Pattern indicates distance &

direction of food source

Bee Dance- Round Dance

This is used when the source of food (nectar or pollen) is less than 100 meters away

Bee Dances- Waggle Dance

For food supplies more than 100 meters the waggle dance is used.

MetamorphosisTwo Types:1. Incomplete

young look like mini adults

egg →nymph (instar)→ adult

E.g. grasshopper, arachnids, centipedes, millipedes

Metamorphosis2. Complete

young do NOT look like adults

egg → larva

→ pupa (cocoon/chrysalis)

→ adultE.g. bees, butterflies,

moths, beetles

Why So Successful?Why So Abundant?

What are six reasons that Arthropods are so successful?