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Flashcards in echinodermata Deck (24)
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1
Q

3 phyla of deuterostomia

A

echinodermata
hemichordata
chordata

2
Q

share developmental features in deuterostomes

A

blastopore => anus

radial, indeterminate cleavage. eucoelom via enterocoely

3
Q

synapomorphies of deuterostomia

A

pharyngeal slits

- three part body coelom

4
Q

main unique of echinoderms

A
  • pentaradial symmetry
  • endoskeleton made of calcium carbonate
  • ossicles connected by mutable collagenous tissues under neuronal control
  • water vascular system
5
Q

pentaradial symmetry

A

oral and aboral surface. radial bc sessile, sedentary, suspension-feeding.

6
Q

endoskeleton of calcium carbonate

A

ossicles held together by living tissue

7
Q

ossicles connected by mutable collagenous tissue under neuronal control

A

soft and floppy to rock hard by changing collagen texture at will. dont waste energy on muscular contractions.

8
Q

special ossicles in sea urchins & starfish

A
  • pedicellariae. look like jaws, pinch thru muscular action
9
Q

water vascular system

- how many coeloms?

A

5 coeloms. lined with cilia to aid in circulation. fluid no isosmotic with sea water. - add K

10
Q

function of polian vesicle?

A

help maintain internal pressure

11
Q

tube feet extend how?

A

hydrostatic pressure form ampulla

12
Q

primary function of water vascular systme?

A

feeding. locomotion arose later

13
Q

name arms of ehinoderm

A

opposite madreporite = A

counter clockwise on aboral surface

14
Q

what morphology do echinoderms lack?

A

brain, cns, ganglia, no excretory organs. lack eyes, no gas-xchange. lack intestine, and anal opening

15
Q

reproduction and development in echinoderms

A

separate sexes.
broadcast sperm.
may be brooded eggs: lecithorophy, may be braodcast - planktotrophic

larva differ. but have bilateral symmetry.

16
Q

which class is most basal?

A

crinoidea

17
Q

4 clusters in 2 clades

A

long-armed: asteroidea, ophiuroidea

armless: echinoidea + ophiuroidea

18
Q

crinoidea

A

suspension feeders, oral up. pinnules on arms. multiples of 5 arms.
capture suspecded particles, flick to ambulacral grooves. face arms to water flow. oral side is not to flow tho.

19
Q

asteroidea

A

arms well-developed. not clearly set off from central disk.
oral down. aboral (with madreporite) up.
crawl with tube feet. opportunistic feeders. evert stomach and liquify food.

20
Q

class ophiuroidea

A

oral + madreporite down. 5 arms clearly demarcated arms

21
Q

class echinoidea

A

sea urchins, sand dollars.
- armless.
globular = urchin. flat = dollar.
aristotle’s lantern - 5 blade-like teeth. teeth protruded through mouth. grown constantly.

22
Q

class holothuroidea

A

sea cucumber.
secondarily bilaterally symmetrical. anterior - mouth. posterior - anus.
pentaradial symmetry in tentacles.
- endoskeleton reduces to scattered ossicles. madreporite internal.

23
Q

tubules branch off base of respiratory tree- called?

A

cuvierian tubules.

24
Q

gut in holothuroidea

A

retains ancestral torsion loop. deposit feeding - moving tentacles or suspension feeding - more branched tentacles.
-tube feet for locomotion, not feeding.