" The Big Picture!" by Mr C

VSB Science Blog

Echinodermata Gap Notes

Biology 11

Name: _________________________ Date: __________ Block: _____



Phylum Echinodermata

(Greek: echinos = “spiny”, derma = “skin”)

Pages 340-341


I Background:

  • The Phylum Echinodermata includes 6 Subphyla that include a total of 18 Classes. Some of these Subphyla and Classes include:
    • Subphylum: _______________ (Includes 4 Classes)
      • Class: _______________– Brittle Stars
      • Class: _______________ – Sea Stars and Starfish
    • Subphylum: _______________ (Includes 2 Classes)
  • Class: _______________ – Sea Urchins and Sand Dollars
  • Class: _______________ – Sea Cucumbers
  • Echinoderms are completely _______________ and only live on the ocean floor


DID YOU KNOW!!!: The development of Echinoderms after the egg stage is so similar to that of the Chordata, as well as being unique to only those two Phyla that it is believed that the Chordates (Vertebrates) and the Echinoderms share a common ancestor!!!


II Body Plan/Structure:

  • Echinoderms have _______________symmetry, but it is believed that they evolved from a bilaterally symmetrical ancestor
  • Most members of the Phyla are _______________ with _______________similar body segments arrayed around a central core
  • Echinoderms contain the three true germ layers:
    • ________________________________
    • ________________________________
    • ________________________________


  • Defining Characteristics of Echinoderms
  1. All Echinoderms have an _______________ made of _______________, covered with a layer of _______________
  2. Echinoderms possess a _______________
    • This is a system of fluid-filled _______________ that acts like a hydraulic pressure system
    • The system is used for _______________, _______________ and _______________
    • Water is drawn into the water vascular system through a structure called a _______________.
    • The water travels down a structure called a _______________ until it reaches the circular _______________ that encircles the central core
    • The water is passed down to each _______________ through the _______________ where it enters the _______________ (Small bulbs)
    • The _______________ are connected to little sucker-like feet called _______________. The _______________and the _______________ are called _______________


III. Feeding:

  • Most echinoderms have a very _______________ digestive system
  • There is a _______________ that is connected to a _______________ that is connected to an _______________
  • The stomach extends into each arm where digestive juices are released to digest the food
  • undigestible food is released out the anus


DID YOU KNOW!!!: Sea Stars can be deadly carnivores. They will mount their prey

(usually an unsuspecting Bivalve) and wrap their arms around it until the opening of the Bivalve is facing the mouth of the Sea Star. From here the Sea Star pulls the Bivalve open using its sticky tube feet and powerful arms. It then everts its stomach into the Bivalve and digests the Bivalve inside its own protective shell. The Sea Star then pulls its stomach back inside to digest the organic material!!!


DID YOU KNOW!!!: Sea Urchins scrape food off of hard surfaces using a special structure called Aristotle’s Lantern. Who knows, if you study hard and become a famous Philosopher and Biologist you could name an anatomical structure after yourself too!!!

  1. Respiration:
  • The thin-walled _______________allow for simple _______________ to occur
  • Some Echinoderms contain special _______________on their epidermis that aid in respiration


  1. Internal Transport:
  • The Water Vascular System is responsible for transporting _______________, _______________ and _______________ throughout the body


  1. Excretion:
  • The Water Vascular System is used to release metabolic wastes into the surroundings. The wastes are released from the _______________


VII. Response:

  • In general Echinoderms have a very _______________ nervous system
  • They have a central _______________ that surrounds the stomach. The central nerve ring connects to _______________ that extend into and control each arm
  • They can generally only respond to:
    • _______________ – Using special structures found on the epidermis
    • _______________– Some have very very simple _______________ on the tips of their arms


VIII. Movement:

  • Echinoderms are either _______________ or very slow moving
  • They crawl using the Water Vascular System to pump water in and out of their _______________


DID YOU KNOW!!!: The ferocious Sunflower Star is by far the fastest moving Echinoderm and can move at speeds up to 1 meter per minute!!!


  1. Reproduction:
  • The Echinoderms have separate _______________ and _______________ organisms
  • The _______________ of most Echinoderms take up the entire coelom
  • The _______________ and _______________ are simply released into the water by both sexes
  • Once the egg has been fertilized it matures into a _______________symmetrical larvae which eventually matures into the adult

Echinoderms also have the ability to _______________ body parts after they have been damaged or removed

posted by Marc Bernard Carmichael in Biology Eleven,Biology Eleven Notes and have No Comments

No comments

Leave a Reply

Your email address will not be published. Required fields are marked *