Arthropods Most successful phyla 1,000,000 species named Most diverse phyla 2/3 of all named species are arthropods. 80% of arthropods are insects. ½ of named insects are beetles.1,000,000 named species.

Arthropod Diversity Crusteacea-1st appendage is antennae, 2nd is madibles for mouth parts, basically they are biramous. They have gills for respiration.

Arthropod Diversity Uniramia-1st appendages are antennae, 2nd are mandibles for mouthparts. Tracheal respiratory system. Malpighian tubules, uniramous legs. myriapods and insects. ½ of all named insects are beetles. 80% of all named arthropods are insects.

Arthropod Diversity Chelicerata-1st appendage are Chelicerae-pincerlike mouthparts. Book lungs, trachaea.

Characteristics of Arthropods Coelomates Mesoderm lining gut and Ectoderm Bilateral Symmetry Protostomes Blastopore becomes the mouth These are characteristics that we have seen in Annelids (earthworms and leeches), Mollusca(clams, snails, octopi.

Characteristics of Arthropods Segmentation Some fused into tagmata Cephalization Open Circulation Ventral Nerve Cord These are characteristics that we have seen in Annelids (with the exception of the closed circulatory system) Go back to the pictures and have students pick out characteristics that are new that they observe.

Characteristics of Arthropods Jointed Appendages Arthropod means “jointed feet” Antennae, Mouthparts, Legs, Wings One reason they are so successful Exoskeleton Made of chitin, lipids, and proteins Sometimes calcium carbonate Provides protection Another reason they are so successful Compound Eye Molting These are new characteristics that we have seen. What advantages to they serve? In other words, why did they develop?

Jointed Appendages Grasping Sensory Feeding Crawling Swimming Reproduction Defense What would we do without our jointed appendages(knuckles, elbows, knees, etc.?

Exoskeleton Protects from drying out Protects from water pressure Protects from predators Protects from injury Chitin and Protein Strong and Flexible Limits Size Talk about molting.

Compound Eyes Most arthropods have them Individual light sensors Individual lenses Not every arthropod has compound eyes. Simple eyes are for distinguishing between darkness and light. It helps stabilize the insect during flight by identifying the horizon.

Compound Eyes

Arthropod Classification Arthropods Trilobita Chelicerata Crustacea Uniramia EXTINCT We are going to revisit the pictures we saw earlier and identify them as one of these phyla.

Prediction Activity Groups

Chelicerata Include turantulas, spiders, mites, ticks, and horshoe crabs

Crustacea Includes lobsters, crabs, shrimp, hermit crabs, scorpions, crayfish

Uniramia Includes millipedes, centipedes, and all insects

Characteristics of Chelicerates 1st Appendage is the Chelicera Book Lungs Malpighian tubules Trachea Spiders, turantulas, mites, ticks, horshoe crabs

Characteristics of Crustacea 1st appendage is the antennae 2nd appendage is the mandible Gills for respiration Biramous legs Includes lobsters, crabs, shrimp, hermit crabs, scorpions, crayfish

Characteristics of Uniramia 1st Appendages are antennae 2nd Appendages are mandible Tracheal respiratory system Malpighian tubules Uniramous legs Includes millipedes, centipedes, and all insects

Comparison of the Subphyla Chelicerata Crustacea Uniramia Mouthparts Chelicera Mandible Mandibles and Maxillae Antennae None 2 pair 1 pair Sensory Organs Pedipalps Antennules and Antennae Body Regions Cephalothorax Abdomen Head, Thorax, The characteristics that Chelicera, Crustacea, and Uniramia that they have in common are what make them all arthropods. Here are the characteristics that make them different.

Where Do I Belong?

Where Do I Belong?

Where Do I Belong?

Where Do I Belong?

Where Do I Belong?

Where Do I Belong?