Order : Ascidiacea
Biology : The sea squirts are special animals. Although they are filter feeders attached to the seafloor, they are close relatives of the vertebrates.
In fact, they have a cord, a kind of spinal column premise.
This is especially visible in the larva, resembling a fish larva. They also have a heart and gills. The sea squirts have a pair of siphons, one of which sucks up the water, the other expelling it. Water circulates through them using flagella. Plankton is captured by a sticky mucus.
Some of these species are colonial, the individuals inhabit in groups and merge with each other.
