Lesson 24b (the Chordates p1)

Question 1

What is class Agnatha?

Answer 1

The Jawless Fish

Question 2

What are 4 characteristics of class Agnatha (subphylum Vertabrata, phylum Chordata)

Answer 2

1. Jawless fish
2. Do not have paired fins
3. Have a slight tailfin
4. Do not have scales

Question 3

What are the two types of jawless fish (in existence currently)?

Answer 3

1. Hagfish

2. Lampreys

Question 4

What is up with the Hagfish, tell me all about them…

Answer 4

a) Keep notochord into adulthood
b) Have a rudimentary vertebrae, and do not have a vertebral column
c) Usually a foot and a half long
d) Feed on dead and dying animals in the ocean

e) Slime glands: release mucous that allows them to escape the
grip of predators more easily

file:///C:/Users/trgan/Sync/LisA%20school/hagfish.png

Question 5

What is up with the Lampreys, tell me all about them…

(4 things ish)

Answer 5

(((in class Agnathan: Jawless fish)))

e) Have a full vertebral column
f) Range from a few inches to three feet long
g) Skeleton made of cartilage

h) Anadromous: the animal is hatched in fresh water and then migrates to salt water as an adult
(1) Adults spend most of their time in salt water until they are ready to reproduce
(2) After reproduction, the adults die within days.
(3) Some lampreys live in fresh water.

i) Toothed funnel-shaped mouths designed for sucking
(1) Some species are parasitic and use this unique feature to latch onto the bodies of their prey to feed on blood.
(2) AQUATIC VAMPIRES!!

Question 6

What is class Chondrichthyes?

Answer 6

Cartilaginous Fish

Question 7

What are 2 characteristics of Cartilaginous Fish?

Answer 7

1. Skeleton made of cartilage
2. Well-developed skeleton and jaw
   a) Jaw of hard bone
   b) Allows the animal to grasp and rip into food

Question 8

What are the two groups Cartilaginous Fish can be separated into?

Answer 8

Skates and rays

Sharks

Question 9

What are 2 characteristics of skates and rays (a group of Cartilaginous Fish)?

Answer 9

a) Most are marine, and a few freshwater rays
b) Have thin, flat bodies
c) Have large pectoral fins fused to their heads

Question 10

What are 3 differences between skates and rays (a group of Cartilaginous Fish)?

Answer 10

a) Skates lay eggs, whereas rays birth live young
b) Rays have a thin tail with stinging spines, which skates lack
c) Rays are typically much larger than skates

Question 11

Name 2 characteristics of sharks (a group of Cartilaginous Fish)…

Answer 11

a) Predators that feed on living prey

b) Electroreception: sense electrical signals underwater; used to locate prey

Question 12

Explain the structure of sharks (a group of Cartilaginous Fish)…

Answer 12

a) Torpedo-shaped body plan
b) Covered with tiny scales
c) Fins: typically have two medial dorsal fins, caudal fin, anal fin, a pair of pelvic fins, a pair of pectoral fins
d) Five to seven pairs of gill slits
e) Eyes are positioned above the mouth
f) Most have many rows of very sharp teeth

Question 13

Explain the reproduction of sharks (a group of Cartilaginous Fish)…

Answer 13

a) Males have claspers that extend from their pelvic fins that are used for internal fertilization
b) Most females lay their fertilized eggs
c) A few sharks give birth to live young

Question 14

What is class Osteichthyes?

Answer 14

Bony Fish

Question 15

What are 5 characteristics of class Osteichthyes (Bony Fish)?

Answer 15

1. Largest class of vertebrates
2. Found in salt water and fresh water
3. Have bony, calcified, vertebral columns and skulls that give structure and support to their bodies
4. Fins
   a) Typically have: tail fin, (side) pectoral fins, dorsal fins, pelvic fins, and an anal fin
   b) Fins provide motion, maneuverability, and stability in the water
5. Most bony fish have scales and skin
   a) Most have overlapping scales made of small bony plates
   b) Secrete a layer of mucous over their scales that waterproofs them
   c) Scales shield the fish’s body from its environment, protect it from predators, and provide for more efficient movement

Question 16

How do bony fish (class Osteicthyes) obtain oxygen?

Answer 16

They have a respiratory system

1. Gills are the primary respiratory structure of the fish, located at the back of the head
2. Operculum: Large flat gill covers that protect the gills
   a) Fish take water in through the mouth, then open the operculum and pump water over the gills and out the opening.
   b) Carbon dioxide is released and dissolved oxygen is picked up as water moves over the gill filaments.

Question 17

How do bony fish (class Osteicthyes) reproduce?

Answer 17

1. Reproductive organs are located to the rear of their anus
2. Sperm and egg cells are released from the urogenital opening
3. Fertilization:
   a) Most bony fish reproduce via external fertilization (((when sperm and egg cells meet up in the water.)))

               b) Some fish have eggs which hatch inside the mother.
               c) Some fish give birth to live young.

Question 18

Lesson 24b some of the classes in subphylum vertebrata

Answer 18

file:///C:/Users/trgan/Sync/LisA%20school/Lesson%2024b%20Phylum%20Chordata%20Part%201%20summary%20video.mp4