Download The Deuterostomes

THE DEUTEROSTOMES
Echinodermata
Chordata
Quiz (Champaca)
What is the most distinctive structure of echinoderms?
2. What are these structures that operate like suction cups (and are
found at the end of the radial canals)?
3. From what words did "echinodermata" come from? Give the
words and their meanings.
4. In what form are nitrogen-containing cellular wastes released?
5. Give one class under echinodermata and one example(common
name/scientific name).
Bonus:
Answer only one.
1. Give an echinoderm found in the Philippines. (1 point)
2. Give the scientific names of 2 echinoderms. (1 point, 0.5 each)
1.
Radiata
Parazoa
no true tissues
Bilateria
Eumetazoa
Multicellularity
Common Features
Features
# of germ
layers
type of
symmetry
body cavity
fate of
blastopore
type of
digestive
system
Echinodermata
Chordata
triploblasts
bilaterally-symmetric larvae
coelom present
anus develops first
complete digestive system
Distinguishing features
Features
Echinodermata
Chordata
Etymology
echino + dermis
“spiny skin”
chorda
“chord”
General
description
# of species
spiny-skinned marine
animals with a
animals, waternotochord, hollow
vascular system,
dorsal nerve cord,
endoskeleton, and
pharyngeal pouches,
pentaradial
and a post-anal tail
symmetry (adults)
~6,000 sp.
~60,000 sp.
ECHINODERM
BODY PLAN
• bilaterally-symmetric
larvae
• pentaradially-symmetric
adults
• water vascular system
for respiration,
circulation, movement
• CaCO3 endoskeleton
• oral and aboral sides
Phylum
Echinodermata
Feeding
• herbivores, carnivores, filter feeders, detritivores
• food enters water vascular system through the
mouth and waste exits through the anus
Respiration
• diffusion through tube feet and the water vascular
system
Circulation
• water vascular system
Excretion
• metabolic waste exits through tube feet and skin
gills
Response
• simple nervous system: nerve ring, radial nerves,
sensory cells
Movement
• tube feet + muscle fibers attached to endoskeleton
• Endoskeleton may have movable spines/joints
Reproduction
• external fertilization
• separate sexes
• bilaterally-symmetric larvae
Phylum Echinodermata
Asteroidea
sea stars
(Acanthaster)
Ophiuroidea
brittle stars
Echinoidea
sand dollars and sea
urchins (Diadema)
Crinoidea
sea lilies and feather
stars
• notochord – flexible rod between the nerve cord and
digestive tract
• hollow dorsal nerve cord
• pharyngeal slits or pouches connecting inside of
throat to outside of neck (functioned first as filterfeeding devices)
• post-anal tail
• internal segmentation
CHORDATA
BODY PLAN
Phylum
Chordata
Feeding
• herbivores, carnivores, filter feeders, detritivores, parasites
• complete digestive system
Respiration
• aquatic: gills aided by diffusion through moist skin
• terrestrial: lungs
Circulation
• Closed circulatory system, may maintain internal body
temperature (endotherm) or depend on the environment
(ectotherm)
Excretion
• Glands and kidneys
Response
• Centralized and cephalized nervous system with sensory
organs, a brain, and a dorsal nerve cord
Movement
• Muscles attached to an endoskeleton
• Usually with four appendages
Reproduction • Sexual reproduction
• External or internal fertilization
• Often have separate sexes