CHORADATA Flashcards
Subphylum and class?
sea squirts and salps
Subphylum Urochordata
Class Ascidacea
Subphylum and class?
larvaceans
Subphylum Urochordata
Class Appendicularia
What is special about Appendicularians?
Retain “larval” form.
Live in large mucus houses.
Where are Salps’ siphons located?
opposite ends of body for jet propulsion
Where are sea squirt’s siphons located?
at an angle from each other (same side of body)
What is the outer body layer called? What secretes it?
Tunic, secreted by epidermis
What do they have instead of a coelom?
Water chamber (Atrium)
How do they feed?
Majority are suspension feeders. Mucus nets to trap plankton. Few predatory.
How do they do gas exchange?
Over the body wall and pharynx
How do they excrete nitrogenous waste?
Most nitrogenous waste lost across body surface.
Do they have a heart?
Yes
How do they reproduce asexually?
Social and compound tunicates bud to form colonies.
Explain Propagative budding
Propagative budding occurs
during favorable conditions and increases colony size.
Explain Survival Budding
Survival budding during adverse conditions. Colony reduces in size and germative tissue kept until conditions are better.
Gonochoristic or hermaphroditic?
Most hermaphroditic with simple reproductive systems.
Internal fertilization, external fertilization, or both?
External fertilization and internal fertilization with brooding.
What type of cleavage?
Holoblastic, radial cleavage.
What type of gastrulation?
gastrulation by invagination.
What type of larva?
Tadpole larva
Chordate features of tadpole larva?
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.
Describe the nervous system and sensory structures
Reduced nervous system since relatively inactive. Poorly developed sensory structures.
Special structure for food capture in sea squirts?
Mucus covered pharyngeal gill
basket.
