Diversity of Life B - Week 13 - JAWLESS FISH

There are 4 apomorphines that you see in the chordates: hollow dorsal nerve chord, postanal tail, notochord and ….?

Pharyngeal pouches

There are 3 steps to becoming a vertebrate, what are they?

1. Muscularization of the pharynx

2. Cephalization

3. Evolution of vertebrae

What are hox genes?

Group of related genes that specify the anterior-posterior axes of metazoans

Fill in the gap: hagfish have blood that is …… with seawater

iso-osmotic

What structure to hagfish have instead of jaws?

Tooth plates on a protrudable tongue

How do hagfish create leverage to tear flesh from another organism?

Create a knot

How do hagfish defend themselves?

Produce slime

What is the main central part of the vertebrae called?

Centrum

What do the lampreys represent?

The oldest living lineage of vertebrates

Lampreys are diadromous. What does this mean?

Lives in seawater and freshwater in its life cycle

Lampreys are anadromous. What does this mean?

They breed in freshwater

What do lampreys have instead of a jaw?

Buccal funnel