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NAME:_______________________ BLOCK:____________________
Phylum Echinodermata
1. General Characteristics and Body Form
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“echino” means spiny, “dermis” means skin. So they have spiny skin
5 part _____________________ symmetry
o No anterior or posterior. Mouth is called oral surface. Other side is aboral surface
Internal Skeleton
Water Vascular System
o Internal network of fluid filled canals connected to external appendages called
_______________________________
o Involved in feeding, respiration, internal transport, elimination of waste products and
movement
o Opens to outside by sieve-like structure called ______________________________
o Madreporite connected to ring canal that circles the animals digestive system
o From ring canal 5 radial canals extend that have hundreds of movable tube feet
o System works like hydraulic pumps that propel water in or out of tube feet
Suction cuplike structures called tube feet
o Water enters and it expands
o Water exits and it shrinks creating a partial ___________________ so it can hold on to
whatever the foot is touching
o _____________________ of tube feet create a force used for walking or sometimes
feeding
2. Feeding
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Carnivores
o ex) starfish
o use tube feet to pry open clams and scallops
o Flips its ______________________out of its mouth, pours ______________________
and digests prey in its shell
o Once finished eating, stomach moves back in the mouth, leaving behind the empty shell
Herbivores
o Ex.) sea urchins
o Scrape algae from rocks by using five-part _______________
Filter feeders
o Ex.) Sea lillies
o Use tube feet on flexible ____________ to capture plankton that float by on ocean
currents
Detritus feeders
o Ex.) Sea cucumbers
o Take in sand and detritus and digest and pass sand grains in feces
NAME:_______________________ BLOCK:____________________
3. Respiration
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Thin wall of ______________________ forms the main respiratory surface
Some species have skin gills for gas exchange
4. Internal Transport
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Transportation of O₂, food and waste is done by digestive glands and fluids withen body cavity
Gas exchange and metabolic waste occurs through _________________________ and tube feet
5. Excretion
 Solid waste released through anus
 Excrete nitrogen containing cellular wastes in form of ammonia in tube feet and skin gills
6. Response
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Primitive nervous system
Nerve ______________________surrounding the mouth
______________________nerves connecting ring to body sections
Scattered sensory cells are chemical sensitive
Light sensitive eyespots along the arms (detect light or darkness)
Statocysts tell which side of the organism is up
7. Movement
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Tube feet and thin layer of muscle under their endoskeleton
Sea urchins have endoskeleton fused together to form a box enclosing internal organs. They use
moveable spines along with tube feet to creep
Starfish have skeletal plates reduced to tiny vestiges inside soft muscular body so they are
flexible. Move by contraction of muscles in body wall
8. Reproduction
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Some Separate sexes
Some Hermaphrodites
Example, Starfish: sperm and egg produced in testes or ovaries. Fill arms during reproductive
season, shed gametes into water
o Other starfish detect gametes of own species and release their own gametes
o __________________________ fertilization and larvae (which has bilateral symmetry)
swims to bottom of ocean where they mature and metamorphoses into adults (radial
symmetry)
____________________________________: as long as pieces contain central part of body
9. Ecological Role
NAME:_______________________ BLOCK:____________________
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Carnivores control population of other animals
Sea Urchins control distribution of _____________ (if present in large amounts they can
threaten existence of algae)
Research subjects for potential cures against cancer
Check Your Understanding
Label the structures of a star fish
Questions:
1.) Describe two functions of the tube feet
2.) Compare and contrast feeding of a starfish with an animal from phylum Mollusca.
3.) Differentiate between the response system of phylum Echinodermata and phylum Mollusca
4) Describe how the starfish reproduces
5.) Name two distinguishing characteristics of phylum Echinodermata