ch 24: echinodermata Flashcards
(46 cards)
deuterostome development (4)
- radial and indeterminate cells
- folds on archenteron form coelom
- anus develops from blastopore
- nerve cords on dorsal side
echino circ sys
closed
what type of sym do echino larvae hacve
bi
what type of sym do adults have
pentaradial
what is a polian vesicle
dead end of the WVS
3 uses for the WVS
- feeding
- locomotion
- gas exchange surface
what can alter the connective tissues hardness/fluidity
the nervous sys
class stelleroidea (3)
- sea stars
- brittle stars
- basket stars
class echinoidea (2)
- urchins
- sand dollars
class holothuroidea
sea cuces
stelleroidea defining feat
arms radiate from central disc
2 feats if asteroidea/sea stars
- arms thick and not used for locomotion
- predators
4 functs of tube feet
- locomotion
- hold and pull apart prey
- excretion
- resp
stelleroidea feeding (2)
- evert stomach to externally digest prey
- release digestive enzymes (pyloric cecae)
3 protection feats in stelleroidea
- calcareous plates/ossicles
- ambulacral ossicles protect vessels and nerves of the arms
- pedicellariae = pinching jaws
stelleroidea nerves (2)
- uncentralized nerve net
- tube feet at arm tips sense chemicals and light
dermal branchiae in stelleroidea
skin gills - extra area for gas exchange
do stelleroidea do asexual repro?
yes; budding
stelleroidea fert
open
weird thing about bilateral sea star larvae
rudiment forms at the expense of the rest of the larvae until it takes over and becomes the animal
ophiuroidea (2)
brittle and basket stars
3 diffs ophiuroidea have from asteroidea
- arms thinner and more obviously segregated from central disc
- move w/ arms
- arms can drop off at will and regenerate
ophi feeding (4)
- deposit
- suspension
- carnivores
- scavengers
ophi eating (2)
- tube feet bring food to mouth
- buccal podia and jaws compact food into pellets
