by hillary goins zoology 8 th period
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Echinoderms. By Hillary Goins Zoology 8 th Period. Basic Info on Echinoderms. Approximately 6,000 species Found in all oceans of the world Move by suction cup appendages and have skin covered with tiny, jaw-like pincers; their tube feet allow them to break open the shells of bivalves - PowerPoint PPT PresentationTRANSCRIPT
By Hillary GoinsZoology
8th Period
Basic Info on Echinoderms
• Approximately 6,000 species•Found in all oceans of the world•Move by suction cup appendages and have skin covered with tiny, jaw-like pincers; their tube feet allow them to break open the shells of bivalves•All have bumpy endoskeletons covered by a thin epidermis •Endoskeleton is primarily made up of calcium carbonate•Echinoderms use a jaw-like pedicellariae for protection and for cleaning the surface of their body• They have radial symmetry which enables echinoderms to sense from all directions•Contains a water vascular system that allows them to move, exchange gases, capture food, and excrete wastes
CONT’ Basic Info on Echinoderms
• Gases are exchanged and wastes are eliminated by diffusion through the tube feet•Simple nervous system•All echinoderms have a mouth, stomach, and intestines•Do not have a head or brain, but they do have a central nerve ring that surrounds the mouth; They have a nerve ring that extends down the rays•Have cells to detect light and touch, but they so not have sensory organs except for Sea stars•Have bilaterally symmetrical larvae
Class Asteroidea• Common name: Sea Star• 1500 species• Most have 5 rays, but some may contain up to 40 or more• Only echinoderm that contains sensory organs
•Carnivorous and also eat worms or mollusks such as clams
• Contain tapering arms called rays
• Rays are tapered and extended from the central disk
Class Ophiuroidea• Common name: Brittle Stars•2,000 species•Extremely fragile• The rays of a brittle star will break if you pick them up, therefore this is an adaptation to protecting itself from predators•Rays will regenerate in weeks•Do not use their tube feet to move, instead they propel in a slithering motion of their rays.•Feed on dead decaying matter•They use their tube feet to get food particles into their mouth
• Look like pincushions • Disk shaped body covered with
spines• Don’t have rays
• They have long slender tube feet• Their spines protect them from
predators• Contains poisonous fluid that are
located at the tips of the spines• The spines help allow the Sea
urchins to move and burrow into the sand/ground
Sea urchins Sand dollars
• Globe or disk-shaped body with spines
• Don’t have rays• Skeletons have a flower
shape with 5 petals• Living sand dollars are covered with hair-like spines
that are lost when the organism dies
• Their tube feet are modified into gills
• Also, their tube feet on the bottom surface of their body
helps to bring organic particles found in the sand
into its mouth
Approximate
ly 950 species of Echinoids
• Known as Sea cucumbers because of their vegetable cucumber shape
•Have a leathery covering that allows it to be very flexible
•Move by using tentacles and tube feet
•Reproduce by releasing eggs and sperm into water and then fertilization takes place
• For protection, Sea cucumbers create a sticky mass of tubes through the anus, or they may rupture, releasing internal organs. This confuses the predator so the Sea cucumber can make its escape.
•Feed on dead decaying matter • About 1500 species
• Consists of Sea lilies and Feather stars
•Approximately 600 species
• Sea lilies are sessile as adults and Feather stars are only sessile in their larval form
• Capture food particles with their tube feet and move it to their mouth
•Feather stars use feathery arms to move place to place
Feather Star