1. PHYLUM
ECHINODERMATA

3. Spiny skinned (Echino = spiny, dermis = skin)
Living calcium & protein exoskeleton
Water vascular system with tube feet
Sexual reproduction & regeneration
Deuterostomes (anus forms first)

4. Exclusively marine
As adults, they have a form of radial
symmetry (‘penta-radial symmetry’).
The larvae have bilateral symmetry.
Use their tube-feet for movement, feeding and for getting oxygen.

5. Anus 1st Mouth 1st Echinoderms and chordates are deuterostomes
At first glance, sea stars and other echinoderms, may seem to have little in common with phylum Chordata, which includes the vertebrates
Anus 1st
Mouth 1st

6. Echinoderms Sea stars and most other echinoderms
Are slow-moving or sessile marine animals
A thin, bumpy or spiny skin
Covers an endoskeleton of hard calcareous (calcium) plates

8. Unique to echinoderms is a water vascular system
A network of hydraulic canals branching into tube feet that function in locomotion, feeding, and gas exchange
Stomach
Anus
Ring
canal
Gonads
Ampulla
Podium
Radial
nerve
Tube
feet
Spine
Gills
A short digestive tract runs from the
mouth on the bottom of the central
disk to the anus on top of the disk.
The surface of a sea star is
covered by spines that help
defend against predators, as
well as by small gills that
provide gas exchange.
Madreporite. Water can flow
in or out of the water vascular
system into the surrounding
water through the madreporite.
Branching from each radial canal are hundreds of hollow, muscular tube
feet filled with fluid. Each tube foot consists of a bulb-like ampulla and
suckered podium (foot portion). When the ampulla squeezes, it forces
water into the podium and makes it expand. The podium then
contacts the substrate. When the muscles in the wall of the podium
contract, they force water back into the ampulla, making the podium
shorten and bend.
Radial canal. The water vascular
system consists of a ring canal in the
central disk and five radial canals,
each running in a groove down the
entire length of an arm.
Digestive glands secrete
digestive juices and aid in
the absorption and storage
of nutrients.
Central disk. The central
disk has a nerve ring and
nerve cords radiating from
the ring into the arms.

9. Shape of life – Water vascular system

10. The radial anatomy of many echinoderms
Evolved secondarily from the bilateral symmetry of ancestors

11. The radial anatomy of many echinoderms
Evolved secondarily from the bilateral symmetry of ancestors

12. Living echinoderms are divided into five classes

13. Living echinoderms are divided into five classes

14. Sea lilies & feather stars
CLASS CRINOIDEA
Sea lilies & feather stars

15. Sea Lilies and Feather Stars
Class Crinoidea
Feather stars
Swim through the ocean
Crawl about using their long, flexible arms
Sea lilies
Live attached to the substrate by a stalk

16. The most ancient class of echinoderms
Not common today, but the fossil record indicates that they were once widely distributed
Sessile filter feeders with 50+ long, feathery arms
Attached to the ocean bottom by a long, stem-like stalk
Modern sea lilies live at depths of 100 meters or more
Many feather stars live on coral reefs, where they perch on top of rocks at night and use their tube feet to catch floating plankton

17. Sea lily

18. Sea lilies

21. MOVE QUICKLY! This crinoid is swimming through the water by alternately raising one set of arms while lowering another, in a flapping fashion. Crinoids move very slowly on their own, but the current provides plenty of additional movement.
MOVE QUICKLY! This crinoid is swimming through the water by alternately raising one set of arms while lowering another, in a flapping fashion. Crinoids move very slowly on their own, but the current provides plenty of additional movement.

24. With a Crinoid Shrimp
Crinoid shrimp: exact same colouration

25. The white projections are called pinnules
The white projections are called pinnules. This crinoid has its arms retracted. Mainly nocturnal, and commonly keep the arms in a retracted position during the day
The white projections from the arm stalks in this closeup view are called pinnules. This crinoid has its arms retracted. Though many may feed during daylight hours, crinoids normally are nocturnal, and commonly keep the arms in a retracted position during the day

28. CLASS ASTEROIDEA
Starfish
2,000 species

29. (a) A sea star (class Asteroidea)
Sea Stars
Class Asteroidea
Have multiple arms radiating from a central disk
The undersurfaces of the arms
Bear tube feet, each of which can act like a suction disk
(a) A sea star (class Asteroidea)

30. Starfish occur in many colors, & most species have more than five arms.
Starfish creep along the ocean bottom.
Most are carnivorous preying upon the bivalves they encounter as they move.
They evert one of their stomachs inside a bivalve (ie: clam) then digest it extracellulary and ‘suck up the juices’
Some species of starfish are important predators in rocky areas (intertidal zones) along the coast.

33. TUBE FEET

35. TUBE FEET: starfish can move up to 30cm/min (60feet/hour)
TUBE FEET: starfish can move up to 30cm/min (60feet/hour). Some can go up to 4X as fast as that (Pycnopodia)
TUBE FEET: starfish can move up to 30cm/min (60feet/hour). Some can go up to 4X as fast as that.

40. Crown of Thorns Starfish
Crown of thorns starfish: has 23 arms and up to 60 cm in diameter. EATS CORALS and in large populations wreaks havok on coral reefs.

41. Has 23 arms and up to 60 cm in diameter
Has 23 arms and up to 60 cm in diameter. EATS CORALS and in large populations wreaks havok on coral reefs.

43. From crown of thorns starfish

44. eating mussels http://www.youtube.com/watch?v=cQPlUlE769E
Asterias eating mussels. Starfish that eat bivalves can use their tube feet to hang on to the shell while pulling the two halves of the shell apart. As soon as a gap opens, even a small one, they extend their stomach into the shell and digest the mussel inside!
Many starfish share this ability to extend ("evert") their stomach, whether for eating bivalves or in less specialized ways as an alternative to swallowing their food.

49. We Are Family...

50. REGENERATION
Starfish regeneration: most need at least the central part of the body intact, some only need one ray.

51. Linckia species: only needs one ray to regenerate
Linckia species: only needs one ray to regenerate

52. SUNFLOWER STAR
The sunflower star: usually has 20 arms.
20 arms

54. A MUTANT ASTERIS
A mutant asteris with 6 legs.

55. A SEA CUSHION

57. CLASS OPHIUROIDEA
Brittle stars
over 2,000 species

58. (b) A brittle star (class Ophiuroidea)
Brittle Stars
Class Ophiuroidea
Brittle stars have a distinct central disk
And long, flexible arms
(b) A brittle star (class Ophiuroidea)

59. Live mostly in tropical seas; only ~ 8” long
They use speed for escape especially on coral reefs
They look much like a common starfish, but they have longer, more flexible arms and are thus able to move much more rapidly.
Brittle stars protect themselves by shedding one or more of their arms when attacked. The detached parts keep wriggling violently, distracting predators, while the rest of the animal escapes.
Very sensitive to light – hide during day. NOCTURNAL – eat at night. They are filter and detritus feeders.

62. BRITTLE STAR : Phylum Echinodermata 8 in long
BRITTLE STAR  : Phylum Echinodermata  8 in long. Brittle stars are extremely sensitive to light. Most hide  during the day and emerge at night to feed. They are quick to flee and may readily sacrifice an arm  to save the rest of the body when threatened by predators. Can regenerate lost arms.

72. BASKET STAR
BASKET STARS

75. Sea urchins & sand dollars
CLASS ECHINOIDEA
Sea urchins & sand dollars
over 300
species
700
species

76. Sea Urchins and Sand Dollars
Class Echinoidea
Sea urchins and sand dollars have no arms
But they do have five rows of tube feet that function in movement
(c) A sea urchin (class Echinoidea)

77. Mostly marine grazers that eat large quantities of algae, some are detritus feeders
Sand Dollars live hidden in burrows that they dig in sand or mud
Sea urchins eat holes into rocks and wedge themselves inside during the day and come out only at night
Many sea urchins have a formidable defense in the form of sharp spines.
One type of sea urchin even has small blue poison sacs covering the tips of each spine, ensuring that wounds it inflicts will be painful. 

78. Sea Urchins and Sand Dollars

80. sea urchin fossil

86.                                         
Found on BC coast

90. Heart Shaped Sea Urchin
Heart shaped sea urchin: rare

98. Have pedipalps (like pinchers) used to clean themselves

100. Have pedipalps (like pinchers) used to clean themselves

101. CLASS HOLOTHUROIDEA
Sea cucumbers
500 +
species

102. (e) A sea cucumber (class Holothuroidea)
Sea Cucumbers
Class Holothuroidea
Sea cucumbers
Upon first inspection do not look much like other echinoderms
Lack spines, and their endoskeleton is much reduced
(e) A sea cucumber (class Holothuroidea)

103. As their name implies, these echinoderms look like warty moving pickles with a mouth at one end and an anus at the other
Most sea cucumbers are detritus feeders
They defecate continuously and you can follow the trail of feces to find a sea cucumber
Scarce in shallow water, but hundreds of thousands can be found in herds on the sea floor at great depths
They can evert their guts to confuse a predator, then they will regenerate an entirely new digestive system.
Some species expel sticky substances to attach to a predator. The predator, is glued into a helpless ball

104. Can reach up to 2 feet long! Used to make soup in the orient

108. Found on BC coast

110. If threatened or roughly handled, some species (including this one) eject sticky threads from its anus (right side of photo) called Cuvierian tubules which are toxic to predators and irritating to an unsuspecting diver's skin.
If threatened or roughly handled, some species (including this one) eject sticky threads from its anus (right side of photo) called Cuvierian tubules which are toxic to predators and irritating to an unsuspecting diver's skin.

111. http://www. youtube. com/watch
This Eyed (or Leopard) sea cucumber was upset and has ejected Cuvierian tubules from its anus.
Fortunately this does no permanent harm to the sea cucumber, but the sticky threads are highly irritating to the skin if touched.
This Eyed (or Leopard) sea cucumber was upset with the way I handled it-- and has ejected sticky, white thread-like Cuvierian tubules from its anus. Fortunately this does no permanent harm to the sea cucumber, but the sticky threads are highly irritating to the skin if touched.

117. Pineapple sea cucumber & many sea cucumbers on a sponge

118. Through self-evisceration, a sea cucumber can expel (throw out) all of its internal organs! This either scares off or satisfies predators. The cucumber can then grow another set of internal organs.
The sea cucumber has an interesting and slightly disgusting way of defending itself. Through self-evisceration, a sea cucumber can expel (throw out) all of its internal organs! This either scares off or satisfies predators. The cucumber can then grow another set of internal organs.

120. CLASS CONCENTRICYCLOIDEA
Sea daisies 2
species

121. (f) A sea daisy (class Concentricycloidea)
Sea Daisies
New Class: Class Concentricycloidea
Sea daisies were discovered in 1986
And only two species are known
(f) A sea daisy (class Concentricycloidea)