Lecture 32 - Chordates

Question 1

4 major physical characteristics of chordates

Answer 1

1. notochord
2. dorsal hollow nerve chord
3. pharyngeal slits
4. post-anal tail

Question 2

Subphylum Cephalochordata

Answer 2

(lancelets)

Question 3

Subphylum Cephalochordata (characteristic/env./nutr.)

Answer 3

• basal chordates
• environment: marine
• nutrition: suspension feeders

Question 4

Subphylum Urochordata

Answer 4

tunicate, sea squirts

Question 5

Subphylum Urochordata (env./nutr.)

Answer 5

environment: marine
nutrition: suspension feeders

Question 6

2 characcteristics of Subphylum Urochordata

Answer 6

1. two siphons, adult animals without backbones

2. “tadpole” larva

Question 7

What are the Peter Pan of tunicates?

Answer 7

Larvaceans, they never grow up

Question 8

What are pelagic tunicates? importance?

Answer 8

• salps

- important component of some pelagic ecosystems

Question 9

Subphylum Myxini

Answer 9

hagfish

Question 10

Subphylum Myxini (env./nutr.)

Answer 10

environment: aquatic
nutrition: scavengers

Question 11

3 characteristics of Myxini

Answer 11

2. 3.

Question 12

Subphylum Petromyzontida

Answer 12

lampreys

Question 13

Subphylum Petromyzontida (env./nutr.)

Answer 13

environment: aquatic
nutrition: parasitic (ecoparasite)
- uses rasping tongue to penetrate skin of prey + inject blood/other tissues

Question 14

3 characteristics of Subphylum Petromyzontida

Answer 14

1. jawless
2. vertebrates
3. cephalization

Question 15

Subphylum Chondrichtyes

Answer 15

sharks + rays

Question 16

Subphylum Chondrichtyes (env./nutr.)

Answer 16

environment: aquatic
nutrition: carnivores + filter feeders
- spiral valve increases SA

Question 17

Subphylum Chondrichtyes (body)

Answer 17

haw + paired fins + cartilage endoskeleton

Question 18

Subphylum Chondrichtyes (reproducition)

Answer 18

internal fertilization

Question 19

Subphylum Chondrichtyes (3 major senses)

Answer 19

1. sharp vision
2. olfaction
3. lateral line detects low freq. vibrations

Question 20

What are rays?

Answer 20

• Flattened bottom dwellers

- related to sharks

Question 21

Subphylum Actinoptergii

Answer 21

ray-finned fishes

Question 22

Subphylum Actinoptergii (class)

Answer 22

Osteichthyes (bony fish)

Question 23

Subphylum Actinoptergii (body, 4)

Answer 23

1. ossified endoskeleton
2. maneuverable swimmers
3. swim bladder
4. operculum (gill-breathers)

Question 24

Subphylum Actinoptergii (reproduction)

Answer 24

variable

Question 25

Subphylum Actinoptergii (senses)

Answer 25

lateral line

Question 26

Why are Subphylum Actinoptergii neutrally bouyant?

Answer 26

swim blatter

Question 27

Subphylum Actinistia

Answer 27

oelacanth

Question 28

Subphylum Actinistia (body/evolution)

Answer 28

Body: muscular pectoral + pelvic fins, bony skeleton
Evolution: lobe fins evolve into limbs + feet

Question 29

Subphylum Dipnoi

Answer 29

lungfish

Question 30

Subphylum Dipnoi (environment, body, evolution)

Answer 30

Environment: freshwater
Body: have lungs + gills
Evolution: sister group of tetrapods

Question 31

_____ were first tetrapods to spend substantial time on land

Answer 31

amphibians

Question 32

What is Synapomorphy?

Answer 32

tetrapod limb

Question 33

3 characteristics of tetrapod limb?

Answer 33

1. Attached to body, one long bone (femur, humerus)
2. Two distal long bones (tibia, fibulua; ulna, radius)
3. Group of smaller bones forming foot or hand

Question 34

Subphylum Amphibia

Answer 34

frogs, salamanders etc.

Question 35

Subphylum Amphibia (environment)

Answer 35

water (larvae), land (adults

Question 36

Subphylum Amphibia (reproduction)

Answer 36

external fertilization

Question 37

Subphylum Amphibia (body)

Answer 37

• 4 limbs (descended from modified fins),

- moist skin (gas exchange)

Question 38

Subphylum Amphibia (evolution)

Answer 38

aquatic-terrestrial transition happened during carboniferous

Question 39

Subphylum Amphibia (reason’s for evolution)

Answer 39

1. Moist environment
2. Abundant food
3. Little competition