Lecture 31 invertebrates Mollusca, Annelida, and Ecdysozoans-Arthropoda

Phylum Mollusca includes?

• Snails and slugs

• Osyters and clams

• Octopuses and squids

Describe the shells of Mollusca

• many have a protective calcium carbonate shell

• Some, like slugs, squids, and octupusese, have a smaller ore reduced internal —- that helps them move quickly by compressing their body

What are the three man body plans of Mollusca?

• Muscular foot

• Visceral mass

• Mantle

In Mollusca this is used for movement?

Muscular foot

In Mollusca this contains most of the internal organs?

Visceral mass

In Mollusca this uses tissue fold that covers the visceral man and forms the shell?

Mantle

What are Annelids?

• Segmented worms

• Live in marine,. freshwater, and damp soil habitats

What are the body features of Annelids?

• Have a coulomb (a body cavity)

• Size varies from less than 1 nm to over 3 meters long

What is another name of Ecdysozoans?

Arthropoda

• Animals with a cuticle (tough outer layer)

• The cuticle is made of chitin and forms the exoskeleton

• The exoskeleton is shed during ecdysis (molting)

Ecdysozoans (Arthropoda)

Arthropod has a body plan that divided into sections which is called?

Segmented body

Arthropod has a body plan made of chitin which is called?

Exoskeleton

Arthropod has a body plan that is made for movement and other functions called?

Jointed appendages

Arthropods have existed since the?

Cambrian explosion

In Arthropod how did the body plan change?

• Over time, body segments joined to form specialized regions for feeding, walking and swimming

• Changes in How genes (genes that control development) likely caused diversity in body plans

Arthropod have modified appendages used for?

Walking, feeding, sensory functions, reproduction, and defense

Arthropod have an exoskeleton used for?

• Making of protein and chitin

• provides protection and muscle attachment

• Allowed arthropods to colonize land, protecting them from drying out

What are the sensory features of Arthropod?

Eyes, antennae, and olfactory receptors (used for touch and smell)

What are the circulatory system Arthropod?

• Open circulatory system where hemolymph (circulatory fluid) flows around tissues in a body cavity called the hemocoel

• The hear pumps the hemolymph to nourish the body