Phylum Chaetognatha Phylum Echinodermata Phylum Hemichordata Chapter 22 Flashcards
What clade and Phylum is under phylum Deuterostomia?
Clade Ambulacraria and Phylum Chordata
What 2 Phylums are under Clade Ambulacaria?
Phylum Echinodermata and Phylum Hemichordata
What 5 classes are under Phylum Echinodermata?
Class Asteroidea, Class Crinoidea, Class Opiuroidea,Class Echinoidea, and Class Holothuroidea
Name the clades and phylums that are under them, starting with clade deuterostomia. there are ten all together
Clade deuterostomia
- Clade Ambulacraria and Phylum Chordata
Under Clade Ambulacraria there is
-Phylum Echinodermata and Phylum Hemichordata
Under Phylum Echinodermata there is
-Class Asteroidea, Class Crinoidea, Class Opiuroidea,Class Echinoidea, and Class Holothuroidea
is Phylum Chaetognatha in Clade Protostomia or Clade
Deuterostomia?
it is in both
what are synapomorphies (4) of Clade Deuterostomia?
Synapomorphies:
* Blastopore becomes anus (mouth forms second)
* True coelom formed via enterocoely
* Gill slits
* Radial Cleavage
Describe the features that unite chaetognaths with protostomes and with deuterostomes.
– Protostomia: have cuticle, longitudinal muscles only
– Deuterostomia: mouth not from blastopore; true coelom
22.2 How do chatognaths feed? the one that looks like a rod and is both protostome and deuterostome
When a chaetognath captures prey, it retracts its hood, and its teeth and raptorial spines spread apart and then snap shut with startling speed.
22.4 What unique synapomorphies define Phylum Echinodermata? 4
Synapomorphies:
* Calcareous endoskeleton (plates or ossicles)
* Water-vascular system
* Pentaradial symmetry
* Loss of gill slits
22.5 Describe the synapomorphy(2) found in Class Crinoidea
-Sea lilies and Feather Stars
-under Phylum Echinodermata
-looks like it has a stem with flower on top and the other one looks like a fern
Synapomorphy = open ambulacral grooves; tube feet move food
22.5 Describe the synapomorphy(2) and unique features(8) found in Class Asteroidea
-sea star
Synapomorphies:
* Suckers on tube feet
* Arms broadly
connected to disc
-Pedicellariae
-Dermal branchiae (= papulae)
-Madreporite
-Ambulacral area with
ambulacral groove
-Stereom structure
-Catch collagen
-Water-Vascular System
22.5 Describe the unique features(2) and synapomorphy(1) found in Class Ophiuroidea
* Brittle stars, basket stars
-Synapomorphy = no suckers on tube feet
-No pedicellariae or papulae
** Bursae for respiration & reproduction*
22.5 Describe the unique features(1) and synapomorphy(1) found in Class Echinoidea
* Sea urchin, sand dollar, sea biscuit
- Synapomorphy = Test fused
- Also:
-unique chewing mechanism called Aristotle’s Lantern
22.5 Describe the unique features(4) and synapomorphy(1) found in Class Holothuroidea
sea cucumbers
-Synapomorphy = Leathery bodies with tiny ossicles
Also:
* Ambulacral areas on sole or all over body
* Respiratory tree for excretion and respiration
– Eject their guts for defence
* Pearlfish live in their butt!
22.6 Describe how the water vascular system functions.
- Hydraulic system used for locomotion, food gathering, respiration, excretion
- Water-Vascular System:
– Water enters via madreporite; enters stone canal
– Stone canal leads to ring canal (surrounds mouth)
– Radial canals enter each arm
– Lateral canals connect to each tube foot
– Tube feet (podia)
Ambulacral groove
-movement, transportation of food and various other products and exchange of gases (respiration)
Pedicellariae
Tiny pincers; protection & clean debris
Papulae (dermal branchiae)
Thin projections of peritoneum (lining of
coelom); used for respiration
Pyloric ceca
digestive glands
Bursae
respiration & reproduction
Periproct
-growth and balancing the pressure
-region that surrounds
the anus
Aristotle’s lantern
biting and rasping
Madreporite
filter water into the water vascular system
- (entrance to water vascular system)
and anus
Ossicles
helps with movement and protection
in the outer wall of the starfish
catch collagen
Space between ossicles that allows the sea star to hold its position for a long period of time without using its muscles
22.6 Describe how the water vascular system functions.
Water-Vascular System:
– Water enters via madreporite; enters stone canal
– Stone canal leads to ring canal (surrounds mouth)
– Radial canals enter each arm; internal, lie atop ambulacral ridge
– Lateral canals connect to each tube foot
– Tube feet (podia)
Autonomy
can regenerate
22.8 What feature(s) unite Phylum Hemichordata and Phylum Echinodermata in the Clade
Ambulacraria?
true coelom: 3 parts
22.9 What are the unique synapomorphies that define Phylum Hemichordata?
Buccal Diverticulum
(called a ‘stomochord’)
Does Phylum Hemichordata have a notochord?
No
22.10 Why is the buccal diverticulum not homologous with the notochord? (i.e., what is the
difference between a notochord and a buccal diverticulum?)
The buccal diverticulum is a hollow evagination of the anterior wall of buccal cavity, whereas the notochord is a long solid rod formed from the roof of the archenteron.
What are the classes in Phylum Hemichordata and list their features
- Class Enteropneusta (Acorn Worms)
– Buccal diverticulum (protocoel) can fill with water; use hydrostatic pressure to burrow
– Deposit & suspension feeders; ciliary mucus feeders
– Gill slits do not contain gills; respiration via branchial epithelium & body surface
– Dorsal nerve cord hollow in some species - Class Pterobranchia
– Sedentary tube dwellers
- Class Enteropneusta (Acorn Worms) features
-Buccal diverticulum (protocoel) can fill with water
-Deposit & suspension feeders
-Gill slits do not contain gills
Class Pterobranchia feature
– Sedentary tube dwellers
