FISH 310 Lecture 20: Lecture 20 Echinodermata II
10 Jun 2018
School
Department
Course
Professor
Phylum Echinodermata
Subphylums
Subphylum Crinozoa
Class Crinoidea - sea lilies and feather stars
Characteristics:
Body held above substrate by stalk or grasping cirri
®
700 extant species
100 sea lilies (4 orders)
◊
600 feather stars (1 order)
◊
®
Very ancient class
Some extinct species were over 65 feet tall
◊
®
Stalk or cirri
®
(semi)-sessile suspension feeders
®
Oral surface up
®
Food collected with tube feet
Inside the ambulacral grooves, help manipulate
food into the mouth
◊
®
Regeneration
®
Often on coral reefs
®
□
Feeding
Passive suspension feeders
®
Extend all appendages
®
Podia secrete mucus
®
Food caught and flicked into ambulacral groove
®
□
Locomotion
Sea Lilies
Stalk contains no musculature
◊
MCT orients body
◊
®
Feather Stars
Cirri cling to substrate
◊
Crawl - terminal hooks on arms
◊
Swim
◊
®
□
WVS
Similar to Asteroidea, except:
No madreporite
◊
Ring canal has numerous stone canals opening into
coelem
◊
WVS connected to environment though ciliated
tubes that penetrate tegem
◊
Ampullae present
◊
®
□
Reproduction
No asexual reproduction
®
Dioecious
®
Gonads in pinnules
®
Spawn by rupturing pinnule walls
®
Some brood, viviparous
®
□
§
○
Subphylum Echinozoa
Characteristics
Defining character = lack of arms□
§
Classes
Class Echinoidea - sea urchins, heart urchins and sand dollars
General Information
~1000 extant species
◊
Body is spherical or flattened to a disc
◊
6-40+ cm in diameter
◊
Defining Characters:
Ossicles form a rigid test
}
Podia pass through ambulacral plates
}
Have complex mouthparts called Aristotle's
lantern
Highly developed mouthparts
–
Ossicles and muscles
5 primary ossicles, up to 35
w
–
Mouth is surrounded by peristomal
membrane and 5 large buccal podia
–
Some have gill outfoldings around the
mouth
–
Teeth can protrude from the mouth
–
}
◊
®
Anatomy
Ossicles form plates that fit together as an
inflexible test
◊
Grow through addition of calcareous material to
edge of existing ossicle and formation of new
ossicles
◊
Podia pass through pores in the ambulacral zone
◊
Interambulacral zone is devoid of tube feet, spines
are prominent
5 ambulacral plates, 5 interambulacral zones
}
Podia have well-developed suction cups at
ends
}
◊
®
Vision?
Urchins placed in arena in different-sized dark
circles
◊
Movements of urchin recorded
◊
Urchins moved away/toward target
◊
Photosensitive test?
◊
Whole body may act like compound eye??
◊
®
Feeding and Digestion
Most sand dollars are suspension and deposit
feeders
◊
Most urchins are algal grazers
Many also eat invertebrates and sediment
}
◊
No true stomach
◊
Anus located aborally
◊
®
Locomotion
Urchins
Spines and podia used
}
Spines can scrape into rock
}
◊
Sand Dollars
Use spines instead of tube feet
}
Adapted to soft substrate
}
◊
®
WVS
Essentially the same as asteroids
◊
®
Reproduction
All dioecious
◊
Generally 5 gonads
◊
Gonad empties aborally though gonoduct to
gonopore
◊
Mostly broadcast spawners, some brood
◊
®
Caribbean urchin die-off
Move down algae in order for coral to exist
◊
Mid 1980s huge sea urchin die-off
Spines falling off
}
Empty tests
}
◊
Dying was at a front which suggests a certain
disease was being carried in the current
◊
Coral-Dominated System --> Algae-Dominated
System
◊
®
Trophic Cascades
Sea Urchins are the favorite food of Sea Otters -->
because of protein rich gonads
◊
Many many years pelts of sea otters were highly
sought after --> intensive exploitation
◊
Sea Otters controlled kelp population because of
the control they had on the urchin populations
When Sea Otters present, lots of kelp and
vice versa
Urchins chow down on kelp, on the
kelp fast which kills the rest of it
–
}
◊
Without Kelp
Atmospheric carbon pool, maintaining
carbon cycle to keep it balanced
}
◊
®
□
Class Holothuroidea - sea cucumbers
Characteristics
Vermiform body
◊
Small ossicles embedded in body wall
◊
Respiratory trees
Specialized respiratory structures
}
Paired inside body cavity
}
Cloaca pumps water across trees
}
Some fish live symbiotically inside cucumber
anus
}
◊
®
1200 species
®
Anatomy
Most have layers of longitudinal and circular
muscles in body
◊
Podia confined to ambulacral strips
◊
Mouth surrounded by feeding tentacles
◊
Cloaca on aboral end used for respiration and
water elimination
◊
Many body forms!
◊
®
WVS
Similar to other echinoderms
◊
Ring canal supported by calcareous ring
◊
Madreporite suspended inside coelem
◊
Often have large Polian vessicles
◊
®
Locomotion
Generally slow, many sessile
◊
Pelagic species swim
Webbed papillae that form tips
}
◊
Burrowing
Peristalsis
}
◊
Crawling
Tube Feet
}
◊
Drag themselves
Buccal podia
}
◊
®
Defense
Bright coloration
◊
Fill with water - turgid
◊
Cuverian tubercles - sticky and/or toxic
◊
True evisceration
◊
®
Reproduction
Only have one gonad - unique within the
Echinodermata
◊
Most are dioecious
◊
Mid-dorsal gonopore opens between two buccal
podia
◊
Most Free-spawning, some brood
◊
®
Ecology
Large proportion of deep sea biomass
◊
Filter feeders - remove particulates from water
◊
Cucumbers may pass up to 130kg of substrate
through their digestive system per year!
◊
®
□
§
○
-
Lecture 20: Echinodermata II
Monday, May 14, 2018
11:30 AM
Phylum Echinodermata
Subphylums
Subphylum Crinozoa
Class Crinoidea - sea lilies and feather stars
Characteristics:
Body held above substrate by stalk or grasping cirri
®
700 extant species
100 sea lilies (4 orders)
◊
600 feather stars (1 order)
◊
®
Very ancient class
Some extinct species were over 65 feet tall
◊
®
Stalk or cirri
®
(semi)-sessile suspension feeders
®
Oral surface up
®
Food collected with tube feet
Inside the ambulacral grooves, help manipulate
food into the mouth
◊
®
Regeneration
®
Often on coral reefs
®
□
Feeding
Passive suspension feeders
®
Extend all appendages
®
Podia secrete mucus
®
Food caught and flicked into ambulacral groove
®
□
Locomotion
Sea Lilies
Stalk contains no musculature
◊
MCT orients body
◊
®
Feather Stars
Cirri cling to substrate
◊
Crawl - terminal hooks on arms
◊
Swim
◊
®
□
WVS
Similar to Asteroidea, except:
No madreporite
◊
Ring canal has numerous stone canals opening into
coelem
◊
WVS connected to environment though ciliated
tubes that penetrate tegem
◊
Ampullae present
◊
®
□
Reproduction
No asexual reproduction
®
Dioecious
®
Gonads in pinnules
®
Spawn by rupturing pinnule walls
®
Some brood, viviparous
®
□
§
○
Subphylum Echinozoa
Characteristics
Defining character = lack of arms
□
§
Classes
Class Echinoidea - sea urchins, heart urchins and sand dollars
General Information
~1000 extant species
◊
Body is spherical or flattened to a disc
◊
6-40+ cm in diameter
◊
Defining Characters:
Ossicles form a rigid test
}
Podia pass through ambulacral plates
}
Have complex mouthparts called Aristotle's
lantern
Highly developed mouthparts
–
Ossicles and muscles
5 primary ossicles, up to 35
w
–
Mouth is surrounded by peristomal
membrane and 5 large buccal podia
–
Some have gill outfoldings around the
mouth
–
Teeth can protrude from the mouth
–
}
◊
®
Anatomy
Ossicles form plates that fit together as an
inflexible test
◊
Grow through addition of calcareous material to
edge of existing ossicle and formation of new
ossicles
◊
Podia pass through pores in the ambulacral zone
◊
Interambulacral zone is devoid of tube feet, spines
are prominent
5 ambulacral plates, 5 interambulacral zones
}
Podia have well-developed suction cups at
ends
}
◊
®
Vision?
Urchins placed in arena in different-sized dark
circles
◊
Movements of urchin recorded
◊
Urchins moved away/toward target
◊
Photosensitive test?
◊
Whole body may act like compound eye??
◊
®
Feeding and Digestion
Most sand dollars are suspension and deposit
feeders
◊
Most urchins are algal grazers
Many also eat invertebrates and sediment
}
◊
No true stomach
◊
Anus located aborally
◊
®
Locomotion
Urchins
Spines and podia used
}
Spines can scrape into rock
}
◊
Sand Dollars
Use spines instead of tube feet
}
Adapted to soft substrate
}
◊
®
WVS
Essentially the same as asteroids
◊
®
Reproduction
All dioecious
◊
Generally 5 gonads
◊
Gonad empties aborally though gonoduct to
gonopore
◊
Mostly broadcast spawners, some brood
◊
®
Caribbean urchin die-off
Move down algae in order for coral to exist
◊
Mid 1980s huge sea urchin die-off
Spines falling off
}
Empty tests
}
◊
Dying was at a front which suggests a certain
disease was being carried in the current
◊
Coral-Dominated System --> Algae-Dominated
System
◊
®
Trophic Cascades
Sea Urchins are the favorite food of Sea Otters -->
because of protein rich gonads
◊
Many many years pelts of sea otters were highly
sought after --> intensive exploitation
◊
Sea Otters controlled kelp population because of
the control they had on the urchin populations
When Sea Otters present, lots of kelp and
vice versa
Urchins chow down on kelp, on the
kelp fast which kills the rest of it
–
}
◊
Without Kelp
Atmospheric carbon pool, maintaining
carbon cycle to keep it balanced
}
◊
®
□
Class Holothuroidea - sea cucumbers
Characteristics
Vermiform body
◊
Small ossicles embedded in body wall
◊
Respiratory trees
Specialized respiratory structures
}
Paired inside body cavity
}
Cloaca pumps water across trees
}
Some fish live symbiotically inside cucumber
anus
}
◊
®
1200 species
®
Anatomy
Most have layers of longitudinal and circular
muscles in body
◊
Podia confined to ambulacral strips
◊
Mouth surrounded by feeding tentacles
◊
Cloaca on aboral end used for respiration and
water elimination
◊
Many body forms!
◊
®
WVS
Similar to other echinoderms
◊
Ring canal supported by calcareous ring
◊
Madreporite suspended inside coelem
◊
Often have large Polian vessicles
◊
®
Locomotion
Generally slow, many sessile
◊
Pelagic species swim
Webbed papillae that form tips
}
◊
Burrowing
Peristalsis
}
◊
Crawling
Tube Feet
}
◊
Drag themselves
Buccal podia
}
◊
®
Defense
Bright coloration
◊
Fill with water - turgid
◊
Cuverian tubercles - sticky and/or toxic
◊
True evisceration
◊
®
Reproduction
Only have one gonad - unique within the
Echinodermata
◊
Most are dioecious
◊
Mid-dorsal gonopore opens between two buccal
podia
◊
Most Free-spawning, some brood
◊
®
Ecology
Large proportion of deep sea biomass
◊
Filter feeders - remove particulates from water
◊
Cucumbers may pass up to 130kg of substrate
through their digestive system per year!
◊
®
□
§
○
-
Lecture 20: Echinodermata II
Monday, May 14, 2018 11:30 AM
Document Summary
Class crinoidea - sea lilies and feather stars. Body held above substrate by stalk or grasping cirri. Some extinct species were over 65 feet tall. Inside the ambulacral grooves, help manipulate food into the mouth. Ring canal has numerous stone canals opening into coelem. Wvs connected to environment though ciliated tubes that penetrate tegem. Class echinoidea - sea urchins, heart urchins and sand dollars. Body is spherical or flattened to a disc. Mouth is surrounded by peristomal membrane and 5 large buccal podia. Ossicles form plates that fit together as an inflexible test inflexible test. Grow through addition of calcareous material to edge of existing ossicle and formation of new ossicles. Podia pass through pores in the ambulacral zone. Interambulacral zone is devoid of tube feet, spines are prominent. Urchins placed in arena in different-sized dark circles. Most sand dollars are suspension and deposit feeders. Move down algae in order for coral to exist.
