Fishes

Question 0

What are the two classes of jawless fishes?

Answer 0

Hagfish: myxini

Lampreys: cephalaspidomorphi

Question 1

Who were the earliest vertebrates?

Answer 1

Jawless fishes or Agnathans

Question 2

What vertebrae characteristics do jawless fishes have and lack?

Answer 2

Lack:
vertebrae or rudimentary vertebrae
No paired appendages or swim bladders.

Have: cranium & other vertebrae characteristics

Question 3

Lampreys

Answer 3

• Live in marine or fresh waters
• spawn in fresh water (Anadromous)
• ammocoetes larva that suspension feed & grow in 3-7 years b4 becoming adults
• adults attach themselves to fish & suck out body fluids problem
• notochord & rudimentary vertebra
• 7 pairs of gills
• well developed eyes & sense organs

Question 4

Hagfish

Answer 4

• Marine fish that feeds on annelids,molluscs, crustaceans, & dead or dying fishes.
• scavengers & predators.
• blind w/ keen sense of smell & touch.
• 2 keratinized teeth/plates
• generate quantities of slime.