1. The document provides information about fish, beginning with their classification. It notes that there are three main groups: jawless fish, cartilaginous fish, and bony fish. 2. Details are given about lampreys, which are jawless fish that are parasites, attaching to other fish and sucking their tissues and fluids. 3. Information is also provided about hagfish, another jawless fish. Hagfish are worm-like with no eyes, jaws or fins, and use slime as a defense mechanism to create a slime cocoon.

1. Fish Notes
Class:Agnatha
Jawless Fish

2. General Fish Information
• Fish make up half of all vertebrates on Earth.
• 15, 300 marine species
• 9,000 freshwater species
• They first appeared more than 500 million years
ago.
• 3 groups of fish
1. Jawless – Class Agnatha
2. Cartilaginous – Class Chondrichthyes
3. Bony – Class Osteichthyes
• Fish – The term “fish” refers to a single
individual or more than one of the same species.
• Fishes – the term “fishes” refers to more than
one species of fish.

3. 3 Main Body Parts
• 1. Fins – movement

4. 3 Main Body Parts
2. Scales
• protection.
• Many species secrete a
protein-like “slime” that
contains natural antibiotics
to protect them from
disease.
• On many bony fish species
you can count the rings on
the scales to determine
age.

5. 3 Main Body Parts
3. Gills
• Oxygen exchange.
• in through the mouth
• out through the gills
• Oxygen passes out of
water into
bloodstream by
diffusion.

6. 1. Lamprey:
• Parasites
• Primarily freshwater fish –
breed in rivers and lakes and
some move to saltwater as
adults.
• Sucker-like mouth with horn-
like teeth
• Attach to fish and suck up
tissues and body fluids of host.
• Lampreys have an
anticoagulant in the saliva that
keeps the blood of the victim
fluid.
Jawless Fish – Class Agnatha
Lamprey
Lamprey Mouth

7. Jawless Fish – Class Agnatha
• Hagfish
• * no eyes, jaws, scales or
paired fins
• * worm-like body
• * 4-6 short tentacles around
the mouth
• * toothed tongue
• * scavengers or parasites of
slow moving fish
• * produce enormous amounts
of slime – 5 gal/min
• * The slime is a defense
mechanism. – slime cocoon
• * Uses a knot to get rid of
slime - also sneezes
Hagfish slime
Hagfish