Echinoderms (Holothuroidea) Flashcards
1
Q
cucumber ‘skeleton’
A
ossicles embedded in leathery test (body wall)
2
Q
holothuroidea symmetry
A
secondary bilateral
like echinoidea irregularia but parallel to oral/aboral axis
3
Q
holothuroidea madreporite
A
internal
4
Q
tentacles
A
anterior end
modified tube feet connected to water vascular system
for feeding
5
Q
holothuroidea reproduction
A
genital pore at oral end
single gonad
broadcast spawners
6
Q
unusual features of holothuroidea (4)
A
- evisceration
- haemal system- closed circulatory system, increased circulation
- respiratory trees (connected to cloaca, muscular movements pump water in and out)
- cuvierian organs (some)- sticky tubules eviscerated from cloaca for defense
7
Q
cucumber ossicles
A
-often ‘anchors’ and ‘plates’
8
Q
economical importance
A
food (delicacy in some countries)
often severely overfished
9
Q
symbionts
A
pearl fish- live in cloaca
crabs
shrimp
