Exam 3 Ch 14 part 1 Flashcards
What Clade did we learn that Phylum Echinodermata fell into?
Clade Ambulacraria (tree-lined path)
Clade Ambulacraria contains what two deuterostome phyla?
Echinodermata and Hemichordata
What do members of Clade Ambulacraria share?
3 part coelom
similar larval forms
axial complex
Is their mesoderm formed by inpocketing or outpocketing?
outpocketing
What is regulative development?
cell fate is determined by communication with cells around it.
Explain adult versus larval symmetry in Echinodermata.
Adults have pentaradial symmetry while the larva are bilateral symmetrical
Echinodermata are restricted to marine environments because?
they cannot osmoregulate.
Their endoskeleton is 95% calcium carbonate, and has what three structures?
ossicles or plates, spines, and pedicellariae (tiny pincher that has a muscle allowing it to open and close.)
Their unique water vascular system replaces which systems that are present in other animals?
skeletal and circulatory system
What are dermal branchiae used for?
respiration
Echinoderms have mutable connective tissue made of…
Catch collagen
Are they monoecious or dioecious?
dioecious
In Class Asteroidea, they have a central disc and 5+ arms, and what other special structures on the aboral surface?
spines, pedicellariae, dermal branchiae, and a madreporite.
What structures are on the oral surface of Class Asteroidea?
the mouth, Ambulacrum, and Ambulacral groove.
Explain the characteristics of the digestive system in Class Asteroidea.
predators of bivalves, because they are slow
2-part stomach (cardiac and pyloric)
enormous digestive glands in each arm
Explain the characteristics of the reproductive system in Class Asteroidea.
Dioecious pair of gonads in each arm external fertilization Regeneration of lost parts autotomy (can drop a leg)
In Class Echinoidea, what is their special feeding structure called?
Aristotle’s lantern
In Class Echinoidea, what is used for locomotion?
tube feet, as well as spikes
In class Echinoidea, what is different from Asteroidea in terms of body plan?
they have internal pentaradial symmetry instead of external.
In class Echinoidea, what is different about the Ambulacral grooves?
they are closed and radial canals run beneath test.
For irregular Echinoids, like sand dollars and heart urchins, what are spines used for?
To filter particles
In Class Ophiuroidea, where is the madreporite located?
on oral surface
In Class Ophiuroidea, what is used for respiration?
bursal slits are used for gas exchange and also for brood chambers.
In Class Ophiuroidea, what two structures are absent?
dermal branchiae and pedicellariae
In Class Ophiuroidea, where are visceral organs located?
in the central disc
In Class Ophioroidea, describe the Ambulacral groove.
It is closed and covered with ossicles.
Describe the distinctive mouth of organisms in Class Ophiuroidea.
there are five moveable plates that surround the mouth and jaw
Are brittle stars capable of regeneration?
Yes.
In Class Holothuroidea, what is used for locomotion?
ventral tube feet and muscular body waves to move.
In Class Holothuroidea, how is gas exchange achieved?
by respiratory trees, skin, and tube feet.
In Class Holothuroidea, what do they call the 10-30 modified tube feet surrounding the mouth?
oral tentacles
Class Holothuroidea has reduced ossicles and an extended…
oral-aboral body axis.
Are sea lillies sessile?
yes.
IN Class Crinoidea, what is the crown composed of?
the calyx, arms and pinnules.
What is unusual about the mouth and anus of class crinoidea?
they are both on the upper surface.
What structures are missing from Crinoideans?
no madreporite, spines, or pedicellariae
How do those organisms in Class Crinoidea feed?
on small organisms using tube feet and mucous strands.
