Overarching Question:
How does the human body
work to keep you alive?
Guiding Question: How does a Sea star’s
body systems work to keep it alive?
Sea Star Classification
  Kingdom: Animal
  Phylum: Echinoderm
  (Echinoderm means spiny
skin)
 
Class: Asteroidea
Sea Star Symmetry
  Echinoderms are
characterized by radial
symmetry
  Several arms (5 or more,
mostly grouped 2 left - 1
middle - 2 right) radiating
from a central body.
  The body actually consists
of five equal segments,
each containing a duplicate
set of various internal
organs.
Sea Star Body Systems
  Sea Stars have some body systems in common with
Homo sapiens (human beings).
  Sea Star body systems are:
  Digestive
system
  Circulatory and Respiratory system
  Movement system
  Reproductive system
  Nervous System
Sea Star Body Systems Defined:
Body System
Digestive system
Circulatory system
Respiratory system
Movement system
Reproductive system
Nervous system
Your Definition
Sea Star Body Systems Defined:
Body System
Digestive system
Your Definition
Respiratory system
-breaks down food
-absorbs nutrients
-transports food and oxygen to and
from the cells
-takes in oxygen for cell respiration
Movement system
-helps a sea star move
Reproductive system
-makes more sea stars (offspring)
Nervous system
-sends and receives messages to
the body
Circulatory system
Sea Star Coloring Guide:
Lets water into the
Madreporite Water vascular system
Ray
Arm
Anus
Ring
Canal
Eyespot
Senses light
Breaks down &
absorbs nutrients
Radial
Canal
Stomach
Digestive Gland
Produces digestive
juices to help a sea
star break down food
Mouth
Tube
Feet
Suction cups that help
Sea stars move & eat
Ampulla
Which organs belong to what sea star body system?
Body System
Digestive system
Circulatory system
Respiratory system
Movement system
Nervous system
Organs Involved
Which organs belong to what sea star body system?
Body System
Organs Involved
Digestive system
Mouth, stomach, digestive gland,
anus
Circulatory system
Madreporite, stone canal, ring
canal, radial canal, lateral canal
Respiratory system
Madreporite, stone canal, ring
canal, radial canal
Movement system
Ray, Madreporite, stone canal, ring
canal, radial canal, lateral canal,
tube feet/ampulla
Eyespot
Nervous system
Sea Star Scenario
 
 
 
Sea Stars are commonly referred to as Starfish, but they actually are not fish at all but
echinoderms. Starfish characteristically have five arms extending from a central disk like a
star, hence the common name Starfish. Represented by over 2,500 species, families, some
species can be important to a home aquarium. Sea stars are found in all oceans and prefer
rocky places as well as sandy regions in reefs, and very few are found in deep water. Most
prefer to live alone, except for when they find a mate for sexual reproduction.
Although sea stars can reproduce sexually, they can also reproduce asexually. They do
this by regenerating lost arms, and under the best conditions, the lost arm will become a
complete sea star as well. Each arm or ray of a sea star has two rows of tube feet that are
used for attaching to things, moving, and respiration (gas exchange). Movement in a sea
star happens because of its hydraulic system of water-filled channels, called the water
vascular system.
The mouth and stomach of a sea star is located on the underside of the animal in the
central disc. Before food is absorbed, the stomach is often pushed out of the body and
placed over the food to digest it. Smaller Starfish eat the microalgae found on rocks and in
home aquariums. Larger starfish eat other starfish, clams, and some sea anemones. The
Sand Sifting Sea Star efficiently consumes mass amounts of uneaten food. A great addition
to any reef tank, this nocturnally active sea star will move large amounts of sand as it
burrows in search for food. The Sand Sifting Sea Star should be fed a variety of fish foods
into the sand. Otherwise, the sea star will quickly clean an aquarium of left over food, and
then starve, and eventually begin to decay.