Phylum Echinodermata III Flashcards Preview

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Flashcards in Phylum Echinodermata III Deck (10)
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1
Q

Echinoidea Characteristics (3)

A

No arms
Endoskeleton: large flat ossicles (test), spines & pedicellariae
Aristotle’s lantern: device to move teeth

2
Q

Aristotle’s lantern

A

Teeth protruding from the mouth (5 teeth) controlled by a complex of internal ossicles (50) and muscles (60)

3
Q

Regular echinoids

A

Rocky substrates
Locomotion: spines and tube feet (suckers)
Feeding: scrape algae from rocks, shred kelp, capture drift algae with tube feet

4
Q

Irregular Echinoids

A

Superimposed bilateral symmetry due to movement of anus and mouth
Sand/mud substrates
Locomotion: spines only
Feeding: deposit feeding (tube feet)

5
Q

Petaloid Tube Feet

A

Specialized tube feet for gas exchange in sand dollars on the aboral surface
The beating of cilia encourages diffusion into the internal

6
Q

Ophiuroidea (brittle star) body form

A

5 well-articulating arms radiate from a central disk
Highly articulate arms due to vertebral ossicles connected by ball and socket joints
Perivisceral coelom greatly reduced

7
Q

Basket Stars

A

Ophiuroids with branched arms for suspension feeding

Distal ends of branched flexible arms that coil around prey (zooplankton)

8
Q

Ophiuroidea Distinctive Characteristics (6)

A
Central disc with highly flexible arms 
Locomotion by arm rowing 
Arm autonomy (MCTs)
No anus 
Tube feet lack suckers & ampullae 
Bursae for gas exchange
9
Q

Crinoidea (5)

A
Primitive echinoderm characteristics 
Stalk or cirri for substate attachment 
Mouth facing upwards 
Arms with pinnules 
Can lock MCTs of ossicles so they do not expend energy when stationary
10
Q

Crinoidea Primitive character state (5)

A
Central disc with radiating arms 
Ossicles as articulating discs 
Tube feet for suspension feeding 
Mouth oriented upward 
MCTs for long term maintenance of posture with no energy expenditure