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 O 2 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 survival E.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.

Metamorphosis Two Types: 1. Incomplete young look like mini adults egg →nymph (instar)→ adult E.g. grasshopper, arachnids, centipedes, millipedes

Metamorphosis 2. Complete young do NOT look like adults egg → larva → pupa (cocoon/chrysalis) → adult E.g. bees, butterflies, moths, beetles

Why So Successful? Why So Abundant? What are six reasons that Arthropods are so successful?