CHORADATA

Question 1

Subphylum and class?
sea squirts and salps

Answer 1

Subphylum Urochordata
Class Ascidacea

Question 2

Subphylum and class?
larvaceans

Answer 2

Subphylum Urochordata
Class Appendicularia

Question 3

What is special about Appendicularians?

Answer 3

Retain “larval” form.
Live in large mucus houses.

Question 4

Where are Salps’ siphons located?

Answer 4

opposite ends of body for jet propulsion

Question 5

Where are sea squirt’s siphons located?

Answer 5

at an angle from each other (same side of body)

Question 6

What is the outer body layer called? What secretes it?

Answer 6

Tunic, secreted by epidermis

Question 7

What do they have instead of a coelom?

Answer 7

Water chamber (Atrium)

Question 8

How do they feed?

Answer 8

Majority are suspension feeders. Mucus nets to trap plankton. Few predatory.

Question 9

How do they do gas exchange?

Answer 9

Over the body wall and pharynx

Question 10

How do they excrete nitrogenous waste?

Answer 10

Most nitrogenous waste lost across body surface.

Question 11

Do they have a heart?

Answer 11

Yes

Question 12

How do they reproduce asexually?

Answer 12

Social and compound tunicates bud to form colonies.

Question 13

Explain Propagative budding

Answer 13

Propagative budding occurs
during favorable conditions and increases colony size.

Question 14

Explain Survival Budding

Answer 14

Survival budding during adverse conditions. Colony reduces in size and germative tissue kept until conditions are better.

Question 15

Gonochoristic or hermaphroditic?

Answer 15

Most hermaphroditic with simple reproductive systems.

Question 16

Internal fertilization, external fertilization, or both?

Answer 16

External fertilization and internal fertilization with brooding.

Question 17

What type of cleavage?

Answer 17

Holoblastic, radial cleavage.

Question 18

What type of gastrulation?

Answer 18

gastrulation by invagination.

Question 19

What type of larva?

Answer 19

Tadpole larva

Question 20

Chordate features of tadpole larva?

Answer 20

Dorsal ectoderm differentiates as a neural plate which curls to form the dorsal hollow nerve cord.
Pharyngeal gill area differentiates into pharyngeal basket.
Notochord is present.
Post-anal tail.

Question 21

Describe the nervous system and sensory structures

Answer 21

Reduced nervous system since relatively inactive. Poorly developed sensory structures.

Question 22

Special structure for food capture in sea squirts?

Answer 22

Mucus covered pharyngeal gill
basket.