1. PHYLUM
ECHINODERMATA
Echinoderms: Sea stars, brittle stars, feather stars, sea cucumbers, sea
urchins

2. CHARACTERISTICS
• Radial symmetry
• Several arms (5 or
more, mostly grouped 2 left- 1
middle- 2 right) radiating from
a central body.
• Body consist of equal
segments, each containing a
duplicate of various internal
organs.

3. CHARACTERISTICS
• No brain nor hearts
• With eyespots on each arm
• Mouth situated on the
underside and anus on top
(except feather stars, sea
cucumbers and some urchins).
• Contains tube feet with suction
pads controlled by water
vascular system.

4. CHARACTERISTICS
• Some are carnivorous
while others are detritus
foragers.
• Reproduction is through
release of sperms and egg
into the water.
• Capable of regeneration
and fragmentation.

5. TYPES OF ECHINODERMS
•Class Asteroidea
•Class Ophiurodea
•Class Echinoidea
•Class Holothuroidea
•Class Crinoidea

6. WHAT IS THIS?

7. • Cushion starfish (Culcita nouvaeguineae)

8. CLASS ASTEROIDEA
• Carnivorous and feed on sponges and
molluscs some are specialized
feeders.(crown of thorns)
• Doesn’t have hard mouth parts to help
them capture prey.

9. TRIVIA
• Crown of thorns (Acanthaster planci)
• One of the largest and the most venomous
starfish.
• Size reaches up to 50 cm in diameter.
• 10 to 20 spiny arms with formidable thorn like toxic
spines
• Feed on coral polyps
• Predators: Triton shell and some puffer fish

10. CROWN OF THORNS
(ACANTHASTER PLANCI)

11. CLASS OPHIUROIDEA
• Close relatives of sea stars
• Have five snakelike arms which
are highly flexible.
• No replication of internal
organs, just one set in the central
disk.
• Smaller central disk and no anus.

12. • Arms of brittle stars
are fragile. ( Defense
Mechanism)
• Most active and
fastest moving
echinoderms
• Feed on plankton but
also on detritus.

13. • Serpent Stars
• Coiled snakelike
around branches of
gorgonians.

14. TRIVIA
• Basket stars
• Specialized type of brittle
stars
(Astroglymma sculptum)

15. CLASS ECHINOIDEA
Sea urchins
• External chitinous skeleton
and a centrally located jaw
• Some have speherical bulblike cloaca.
• Movable spines are attached
to the body, some are
venomous

16. • Locomotion by tube feet
but also by movement of
the spines on the underside
of the body.
• Generally nocturnal
• Most are algal grazers but
some feed on sponges and
detritus.

19. CLASS HOLOTHUROIDEA
• Don’t have radial symmetry
but are bilateral.
• Cucumber shaped with
elongated muscular, flexible
body with mouth at one end
anus on the other.
• Tentacles present in the
mouth for food collection

20. • Feed on rich organic film
coating sandy surfaces.
• Crawl over the bottom
and ingest sand.
• Move by means of tube
feet.
• Releases its digestive tract
when threatened (defense
mechanism)

22. PHYLUM CRINOIDEA
• Radial symmetry
• Cup-shaped body
• Numerous feathery arms project from a central
disc.
• Have 5 up to 200 arms (pinnules)
• Nocturnal
• Usually cling to sponges.

23. FEATHER STARS

24. • Source: http://www.starfish.ch/reef/echinoderms.html#starfish