1. Agnatha Hagfish & Lamprey
Vertebrate Zoology
Agnatha
Hagfish
& Lamprey

2. Key Features Jaws are absent. Paired fins are generally absent.
Early species had heavy bony scales and plates in their skin

3. Key features con’t
In most cases the skeleton is cartilaginous. The embryonic notochord persists in the adult.
Seven or more paired gill pouches are present.
Hagfish sheds slime layer

4. Key features con’t A light-sensitive pineal eye is present.
The digestive system lacks a stomach.
External fertilization; both ovaries and testes present in individual but gonads of only one sex functional in hagfishes, no larval stage; separate sexes and a long larval stage in lampreys.

5. Jawless, bony plated
Ostracoderm fish
Ordovocian Period
505 mya Paleozoic
Scavengers/
filter feeders

7. Lamprey Classification
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Cephalaspidomorphi
Order Petromyzontiformes
Family Petromyzontidae

11. Lamprey Structure Structure
Round, suckerlike jawless mouth filled with rows of horn-like teeth.
Internal ring of cartilage supports rim of mouth.
Single nostril on dorsal side of the head.
Skeleton doesn’t exist, only cartilage.

12. Lamprey Digestion Digestion
Pierces flesh of prey with numerous small horn-like teeth.
Tongue creates suction and tongue draws back body fluids.
Rasp into the flesh and feed on body fluids.

13. Lampreys
mouth
I luv you

15. External
Fertilization

16. Hagfish Classification
Kingdom Animalia
Phylum Chordata
Class Pteraspidomorphi
Order Myxiniformes
Family Myxinidae
Genus Myxine
Species glutinosa

19. Slime Glands

20. Hagfish secrete
slime when disturbed

22. Hagfish Structure Structure Body supported by heavy cartilage.
91 cm. Long
Continuous fin extending upper and lower body.
No bone structure
Mucous producing pores along body length.

23. Hagfish Hagfish can be found in chilly waters
They tend to live on and in muddy sea floors in very dense groups (up to 15,000 in an area).
Because females tend to produce large eggs in small numbers, their population sizes suggest a low death rate.

24. Hagfish
Diet is made up of marine worms and other invertebrates; dead and dying sea life (eats them from the inside out).
They have a ring of short sensitive tentacles around their mouths.
Large slime glands line their sides along the length of their bodies.
Can sneeze to clear slime from nostrils

25. No jaws. Instead they have two pairs of rasps on top of a tongue
No jaws. Instead they have two pairs of rasps on top of a tongue. They pull meat into their mouths with the tongue, then tear it off the prey with the rasps.

26. Hagfish have a very low metabolism
Hagfish have a very low metabolism. Once they eat, they may not have to again for up to seven months.
Although hagfish have a partial skull, they have no back bone, so are not true vertebrates. What skeleton they do have is made of cartilage.

29. Hagfish Anatomy