Echinoderms- Asteroidea Flashcards
Where is the mouth located in sea stars?
Central disk of the oral or ventral side
Class Asteroidea contains
Sea stars
Aboral surface
The top or dorsal surface if an organism
Ambulacral groove
Grooves located on the oral surface and they hold tubes feet
Tubed feet are also called
Podia
Podia are guarded by what
Movable spines around the margins of the grooves
Tubed feet are used
For locomotion
Light sensitive eyespots which are small tentacles that contain pigments sensitive to light are locate where
At the tip of each arm
Sub-dermal spines and specialized pinchers are called
Pedicellariae
What is the function of Prdicellariae?
Capture small animals and carry them to the mouth
The outer layer of sea stars are covered by the
Epidermis
The epidermis is covered by
A cuticle
The epidermis has what
Neurosensory cells connected to mucus glands
What happens when detritus falls on the body
It is coated with mucus and the ciliates cells sweep the particles away
In sea stars how are ossicles joined together
By muscle fibers and connective tissues making it very flexible
Sea stars feed on
Snails, bivalves, crustaceans, polychates, coral and are all carnivorous
Sea stars digest how?
They every their stomachs out their mouths and externally digest
Sea stars have how many stomachs
2
The lower stomach is the
Cardiac stomach
The upper stomach is the
Pyloric stomach
Extra cellular digestion occurs where
Digestive ceca
Water enters the hydrovascular system where
The sieve plate (madreporite)
From the sieve plate water travels to the stone canal and from the stone canal water travels to the
Ring canal and out the arms through the radial canals
Ballon like structure on the internal side
Ampulla
Podia is
A hollow muscular tube and some species contain a sucker
Gas exchange occurs through
Diffusion through gills, through tubed feet, by water circulation
Excretion occurs through
Water flow or through membranes of the tubed feet
Their nervous system consists of
A nerve ring which contains branches of nerve that run down each arm
For regeneration how much of the nerve ring must be present
1/5
Sea stars are able to regenerate completely in about
A year
There is usually how many breeding seasons a year
1
One female can release how many eggs at once
2.5 million
