Vertebrates

Question 1

what are the features of vertebrates?

Answer 1

they have a backbone called the vertebral column which replaces the function of a notochord and they have a more complex nervous system
- provides rigidity and attachment sites for muscles and other skeletal elements like ribs

Question 2

What is the most basal/ancestral group of vertebrates and what are its characteristics?

Answer 2

the lamprey (petromyzontida)
- it has a skeleton made of cartilage and it has a notochord surrounded by a cartilaginous tube and its cartilaginous tube has little spines (this is the primitive vertebral column)
it has no jaws but it has eyes with lenses
- its larvae resemble lancelets (suspension feeders)

Question 3

What is the habitat/ecology of lampreys?

Answer 3

they are parasites of fish (ectoparasite) –> adults live in lakes and oceans
- they clamp onto the side of fish and rasp away with keratin spine tongue

• they hold onto rocks with their oral suckers when they’re not eating