Top 5 Sea Squirt Facts

The Sea squirt is a sessile round, bell-shaped, urn-shaped, or tubular-shaped marine invertebrate. This petite marine animal has a tough, permeable outer layer made of polysaccharides or poly-carbohydrates, known as the tunic.

Sea squirts are bright-colored animals that vary in shape, size, and tinge. Depending on the subspecies and native origin, they come in myriad hues like brown, orange, pink, white, green, red, blue, and yellow.

Top 5 Surprising Facts About Sea Squirt You Should Know

Top 5 Surprising Facts About Sea Squirt You Should Know

This tunic has two siphons on the upper side. The atrial siphon primarily acts as a pathway where water and food particles enter and exit the sea squirt body. The second siphon is used to eliminate by-products from its body.

As a response to touch, the sea squirt violently ejects water from these siphons, hence their name Sea squirt. If you dare remove a sea squirt from the ocean, you are definitely in for a wet surprise!

The giant Sea squirt uses tentacle-like structures to catch jellyfish and small fish. Read on to discover fascinating fun facts about sea squirts.

  • Sea Squirts Are Hermaphrodites

The Sea squirts have both types of reproductive organs next to the gut or body wall. To reproduce, both males and females release egg and sperm cells from the inhalant siphon directly into the water, where they mix and merge.

Eggs are hatched to form larva within 36 hours and metamorphose into a new juvenile. The resulting larvae resemble a tadpole that attaches itself to a rigid substrate at the bottom of the ocean.

  •  Asexual Reproduction Is Present in Sea Squirts

Some distinctive sea squirts have asexual reproduction by budding. Sometimes a new chain of zooids splits off into new individuals and grows from the original sea squirt to form colonies of sea squirts.

The zooids of the social colonial sea squirts remain independent. Unlike the compound colonial ascidians, budding gives rise to a colony in which the zooids are embedded in a common tunic. Multiple zooids may share a single, common cloacal aperture, but each zooid will still have an independent branchial vent.

  • Sea Squirts Have a Striking Appearance

Identifying tunicates at the bottom of the ocean can be adorable and incredibly fascinating to watch in their juvenile form. One of the epic Sea squirts is the Polycarpa aurata species. It is popularly known as the ox heart ascidian, resembling a purple and yellow animal’s heart.

Another alluring species is the skeleton panda sea squirt. It acquires its name from the white tissues that form the appearance of a spine and skull with eerie panda-like facial features.

  • Sea Squirts Are Toxic

Even with their breath-taking hues, Sea squirts are considered harmful in the immediate seawater they inhabit. As their bodies break down, the dangerous animal can create a vast dead zone. The oxygen consumed and released can foul the surrounding environment.

To escape predators, some Sea Squirts will secrete concentrated acids and chemicals. These toxins pollute the entire ocean structure and are unsafe if consumed.

  • A Sea Squirt Larvae Has a Backbone

Like humans, pinnipeds, whales, dolphins, sharks, and fish, the Sea squirt animals fall under the phylum Chordata. All Chordata are famous for their primitive backbone at a stage in their life.

In Sea Squirt, the notochord and numerous anatomical features of vertebrates are present in the animal’s larval stage. The tadpole larvae are free-swimming and possess a muscular rod-like tail that is flexible. Later, the tail with its notochord and nerve cord is absorbed and disappears as the Sea Squirt attains sexual maturity at the age of a few weeks.


Sea Squirts are animals that can either live alone, attached to a hard surface, or in clumps as a colony. Although its organs are not visible outside its body, the Sea Squirt has many parts resembling the human system. These parts include; the pharynx, heart, circulatory system, nervous system, digestive system,  and reproductive organs.


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