Table of Contents Coral Reef Cart Collection

spiny puffer fish

sponges (not Venus Flower Basket)

octopus beak

Supporting Materials

of organisms

octopus model
ray model

spiny puffer fish

porcupine fish spines

hermit crabs

pencil sea urchin

nautilus shell

ruffled clam shell

sea horses

sea stars

Supporting materials

hermit crab model

Things to Notice/Facts to Share

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  The gastropod shells provide protection from predators. They are composed of calcium carbonate. Notice the variety in the shell sizes and shapes. The smooth surface of the cowrie shell is due to its being mostly covered by the mantle when the animal is alive. This prevents other organisms from attaching to it.
  
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  The spiny puffer fish is able to inflate its body using water or air, making it difficult to swallow. The spines on its body serve the same function.
  
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  The porcupine fish’s spines are particularly sturdy and protect it from being swallowed by predators.
  
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  Hermit crabs utilize empty shells as a home to protect themselves from predators. When they outgrow their shell they must find a larger one and transfer into it.
  
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  The spines on the outer surface of the pencil sea star make it difficult to eat.
  
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  The double shells of the ruffled clam protect it from predators and can close up if the animal is threatened, although it is unable to close its shell completely.
  
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  The outer covering of sea horses has no scales. Their bodies are covered by thin skin stretched over bony plates that are arranged in rings throughout the body. The bony plates make their outer covering hard and difficult to bite through.
  
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  Sea stars have an outer body composed of calcium carbonate components known as ossicles. This makes their outer surface hard to penetrate. Several groups of sea stars possess pincer-like structures known as pedicillaria that may be used in defense.
  
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  Sea stars are able to regrow lost arms. They can autotomize one or more arms to avoid predation. Sea stars can autotomize more than 75% of their body mass and continue to survive.
  

Camouflage/Color

Specimens

octopus beak

sea horses

Supporting materials

ray model

shark model
octopus model

Things to Notice/Facts to Share

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  Both the octopus and cuttlefish are capable of changing color and texture to blend in with their surroundings.
  
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  Sea horses use their prehensile tails to hang on to vegetation and their coloration blends with the colors of the plants.
  
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  Notice that the dorsal surface of the toy ray and shark is a dark color, while the ventral surface is light. This is known as “counter-shading” and enables the animal to be camouflage from above and below. From above it blends in with the dark ocean floor and from below it blends in with the bright sky above it.
  

Commensalism

Specimens

gorgonian coral

hermit crabs

Venus Flower Basket sponge

Supporting materials

Things to Notice/Facts to Share

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  Most corals (both hard and soft) obtain most of their energy and nutrients from photosynthetic, unicellular algae called zooxanthellae that live within their tissues. Such corals require sunlight and grow in clear, shallow water typically at depths shallower than 60 m (200 ft). These algae are responsible for the coloration of the coral.
  
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  A species of fish called a shrimpfish often lives within gorgonian corals. Their slender bodies blend in with the coral skeleton.
  
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  A hermit crab may attach a sea anemone to its shell. The stinging tentacles of the anemone give the crab added protection and the anemone benefits by eating particles of the crab’s food.
  
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  The Venus Flower Basket is a deepwater sponge. A pair of shrimp (male and female) live within the sponge, unable to escape the basket. The shrimp clean the inside of the basket and in return the sponge provides food for the shrimp by trapping it in its fiberglass-like strands and releasing it in to the body of the sponge. The sponge contains bioluminescent bacteria that may attract small organisms for the shrimp to eat. The shrimp will breed and their tiny offspring escape to find a Venus Flower Basket of their own.
  
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  Observe the ruffled clam and note that giant (Tridacna) clams contain symbiotic zooxanthellae that provide them with food by photosynthesis. The beautiful colors of the giant clam mantle are due to these algae.