Sea Star Animal Study and Lapbook
Research by Debbie Palmer
Templates by Ami
Sea Star Lapbook Templates
Pagoo by Holling C. Holling. This book is about a hermit crab, but does contain some information on sea stars.
A House for Hermit Crab by Eric Carle
Starfish by Edith Thacher Hurd (Let’s Read and Find Out Science)
Enchinodermata-comes from the Greek, meaning “spiny skin”. This group includes sea stars, sea urchins, sand dollars, sea cucumbers, and sea lilies.
Asteroidea-comes from the word, “asteroid”. These animals are star shaped.
Ventral side-underneath part of a sea star
Dorsal side-the top or spiny surface of a sea star
Cardiac stomach-the stomach that comes outside of the sea star’s body to grab the food
Pyloric stomach-this stomach digests the food.
Tropical-hot and humid
Temperate-neither hot nor cold
Polar-extremely cold, the areas at the top and the bottom of the world
Omnivore-eating both plants and animals
Zooplankton-small or microscopic animals that float in the oceans
Phytoplankton-microscopic plant life that floats in the oceans
Radial symmetry-animals have radial symmetry if they have no right or left sides, only a top and a bottom. They can be “cut” into equal or similar sections.
Bilateral symmetry-animals that have bilateral symmetry have a left and right side. Each side is the mirror image of the other side.
Sea stars have radial symmetry, which means that their arms radiate (like the sun’s rays) from the central part of the body. They tend to have five arms or multiples of five arms. At the end of each arm is a microscopic eye which allow the sea star to only see light and dark and detect movement. They also have spines on their skin for protection. Although there are many species of sea stars that don’t really have spines, but have a bumpy texture. The ventral side has the “mouth” in the center and the tube feet on the arms. Sea stars have two stomachs: the cardiac stomach and the pyloric stomach. The cardiac stomach can come out of the body and envelope the food. The cardiac stomach begins the digestion process. The food is then transferred to the pyloric stomach to be digested. The sea star’s tube feet are located on the ventral side. They have two functions. They aid in movement and can be used to open scallops or clams.
Habitat and Diet
Sea stars live in tropical, temperate and polar oceans. They are normally found around rocks and coral, but can be found living in the sand. Sea stars cannot live in fresh water. Sea stars are omnivores. Their diet tends to be shellfish such as scallops, oysters, clams or plant material.
Sea stars start as very small larva that float/swim in the ocean. They become a part of zooplankton for about two months and have bilateral symmetry. They survive feeding on phytoplankton. After that they settle out of the zooplankton and begin to develop radial symmetry.
Sea stars move using their tube feet. The feet latch onto surfaces and move in a wave. One body section attaches to a surface as another body section releases. Sea stars are very slow moving. There are a few species that can move rapidly along the sea floor.
Regeneration means that a missing body part can be regrown. Some sea stars are capable of regrowing arms. Most species need the central part of the body unhurt to be able to regrow an arm. However, there are some stars that can regrow a whole new body from a single ray.
There are over 1800 species of sea stars! Some of the most well-known stars are
*Blue sea star
*Japanese sea star
*Carpet sea star
*Eleven-armed sea star
*Pincushion sea star
*Comb sea star
*Crown of thorns sea star
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