What are sea squirts? What are tunicates? What is the worlds strangest looking animal? Weird ocean lifeforms. Facts and information about sea squirts. Trivia about tunicates. Weird looking animals. Learn more about why such odd creatures are considered animals rather than plants. Beautiful, exotic, unusual, animals.
The correct name for Sea Squirts is tunicates, but most spell check programs have never even heard of tunicates yet these animals number in the thousands, with over 3,000 classified and identified. Sea squirts belong in the phylum Chordata. They are found world wide, in salt water, most are found in tropical waters.
One of the most strangest features of the sea squirts is their blood. Sea squirt blood contains high levels of lithium, and transitional metal vanadium.
Another extremely odd fact is that sea squirts are more closely related to vertebrates than to invertebrates, although they look nothing like animals as all. They have no true brain but are sensitive to touch and the detection of sunlight. Sea squirts have hearts that pump blood, pumping it one direction for a few minutes, than the opposite direction for a few minutes.
photo source, picture of two different types of sea squirt
Many sea squirts are hermaphrodites, having both male, and female organs. In their larval stage, most sea squirts look like tadpoles, swimming about looking for a rock, or dead coral, to attach to. At that point, as adults, they sit and siphon water for food. Mostly eating plankton. A few of the larger sea squirts live in deeper parts of the ocean and do eat fish or jellyfish. There are some tunicates that never attach to a surface but remain free swimming all their lives.
Their tube shape bodies have two holes, one for incoming water, one for outgoing. This gives them their other name; Sea squirts. The name tunicate comes from "tunic". Another unusual thing about sea squirts is that they produce cellulose to make their bodies, something that was highly debated for years, as these are one of the only animals known to produce cellulose.
photo source - picture of 3 types of sea squirt, two are easy to see, the third is the large white, purple, and yellow animal to the upper left.
Sea squirts do have predators; they are eaten by snails, crabs, sea otters, birds, and other fish. Some species of sea squirt are consumed as food by people, often eaten raw or cooked in stews. When sold for human consumption they are often labeled sea violets, or sea pineapples.
In some areas sea squirts are considered invasive animals, particularly when they cling to ships, docks, and so forth. They are also a problem in that they compete for food with other filter feeders.
Tunicates have been around since the Cambrian period, before the dinosaurs, but fossils are rare.
All in all, sea squirts are certainly one of the world's most unusual, and odd, animals.