Amazing Invertebrates

Amazing Invertebrate Animal

Invertebrates, or animals with no backbone, are incredibly diverse, important, and fascinating. Invertebrates range in size, with some smaller than a grain of salt and others that can grow to half the length of a football field. Scientists estimate that invertebrates comprise 97% of all species on Earth, and many are older than dinosaurs. Some of the earliest invertebrate fossils date back to 543 million years ago—when the entire state of Oklahoma was submerged by a sea known as the Western Interior Seaway. Today, you can appreciate (and touch) a variety of these prehistoric creatures in our Amazing Invertebrates exhibit. Here, you will find animals that digest food outside their bodies, animals that swim backward, and animals with blue blood!  

Arthropods are a group of animals that have an exoskeleton, jointed appendages (legs), and segmented body parts. Arthropods that have an exoskeleton, or hard protective covering, are called crustaceans. Since their exoskeleton is rigid, they must shed when the crustacean needs to grow. Crustaceans in this exhibit include Ecuadorian white shrimp, giant freshwater prawns, lobsters, hermit crabs, and horseshoe crabs.  

Given that cnidaria means “stinging cell,” it’s no surprise that all cnidarians have nematocytes, which are cells that sting. Some cnidarians use their nematocytes to catch prey, others use it as protection. Cnidarians in this exhibit include jellyfish, and anemones.   

All mollusks are soft-bodied animals, but many of them receive protection from a hard shell. Mollusks that have two shells connected by a hinge are called bivalves; this group of mollusks includes scallops, oysters, and mussels. Surprisingly, octopuses and squid are also classified as mollusks. They belong to a group of mollusks known as cephalopods. The word cephalopod literally means “head-feet,” since they all have a head attached to a set of arms. Oysters are mollusks.  

The word echinoderm means “spiny skin.” Animals in this group are radially symmetric, which means they look the same around their center, unlike humans, who only look the same on the left and right (bilateral symmetry). Echinoderms in this exhibit include sea stars and sea urchins.  


The Amazing Invertebrate exhibit showcases two important symbiotic (two organisms living and interacting together) relationships found in marine environments; upside down and white spotted jellyfish shelter symbiotic algae within their tissues. The energy produced by the algae's photosynthesis is shared with the jellyfish, and the jellyfish provide a safe home for the algae. You will be amazed by our anemone and clownfish exhibit! The clownfish/anemone symbiosis is one of the most well-known examples of symbiosis. The anemone provides a safe home and hiding place for the clownfish without stinging it. Clownfish have a thick layer of mucus to prevent stings and the longer they live in the anemone the thicker the layer gets as it mixes with the anemone’s own mucus. Clownfish return the favor by scaring away predators, feeding the anemone with their waste, and cleaning the anemone. 

Although not invertebrates, Clownfish are also amazing! They are born as males and can later become females. In every clownfish social circle, there is one pair of fish that is larger than all the others; one of these large fish is a mature female and the other is a mature male. If something happens to that large female, the large male in the pair will transform into a female and choose a smaller male to replace his former role as the large male of the group. 

Fun Facts

  • Blue blood from horseshoe crabs is worth $15,000 per quart to the pharmaceutical industry.
  • Jellyfish do not have brains but they do have nerve cells. Jellyfish nerve cells are spread throughout their bodies to form a network called a nerve net. Just like a brain, the nerve net allows jellyfish to take in information from their environment and respond.
  • Sea stars expel their stomachs into their prey, where they secrete digestive enzymes that liquefy the food for the stomach to absorb.
  • Shrimp respond to predators by rapidly flexing their tails, which causes them to jet backward.

Touch Tanks

You can interact with horseshoe crabs, hermit crabs, chocolate chip sea stars, pencil urchins, and Ecuadorian white shrimp!