LAB 7 Flashcards
(23 cards)
what are echinoderms
coelomate deuterostomes with complete guts
how many classes of echinoderms are there
5 class = asteroidea, echinoidea, ophiuroidea, holothuroidea, crinoidea
what is class asterioidea
star fish
what is class echinoidea
sea urchins
what is class ophiuroidea
brittle stars
what is class holothuroidea
sea cucumbers
what is class crinoidea
featehr stars
what are echinoderms main characteristics
triploblastics, deuterostomes, pentaradial symmetry, well developed spacious coelom
where is the mouth in echinoderms
mouth on the ventral oral surface
echinoderms have a head and brain
false
echinoderms are marine
true
do echinoderms have an endo or exoskeleton
endoskeleton of calcerous plates/ossciles
-covered by an epidermis
is the digestive system complete or incomplete
complete
what is the unique water vasuclar system
made up of tube feet, radial channels, medraporite and function in locomotion, feeding, excretion and gas exchange
what is the stereom in echinoderms
biomineral matrix composed on calcium carbonate (calcite) that have a sponge like microstructure. functions as an endoskeleton
class asteroidea key features
primarly carnivorous, predators on benthic invertebrates, cardiac stomach can be everted and endoskeleton
echinoidea key features
spherical to oblong, primarily herbivorous, keystone species
crinoidea key features
most primitive, stalked ie sea daisy, comatulids not stalked, sealillies stalked, all suspension feeders
how do crinoids feed
suspension feeder trapping food in arms using mucus and passing to central mouth
what do crinoids lack
madreporites, ampullae, their gut is u-shaped and have up to 200 arms
ophiuroidea key features
predators, deposit or suspension feeders - and scavengers; deep sea, calcified internal plates or vertebrae
holothuroidea key features
detritus, scavenger or suspension feeders, pelagic, feed using buccal tube feet, much reduced calcification, ossicles embedded in mesoderm
larval life history strategies
dioecious, pelagic larval stage, planktotrophic and lecithotrophic larvae with bilateral symmetry
