Appendicularians are small aquatic organisms that are carried by currents. They belong to the Chordates, a group of animals that includes us vertebrates. They feed on organic particles which they filter from seawater by producing a structure known as a “house”. This house, which is about ten times the size of the animal’s body, has inlet filters that allow the water containing the food particles to enter. When the filters become clogged, the appendicularian exits the house and builds a new one. The abandoned house falls to the bottom of the sea carrying a large amount of organic matter, thus contributing to the marine carbon cycle. The species on display here, known as Oikopleura dioica, lives in most surface waters and has become a ‘model organism’ in developmental biology studies. Since its ovoid body measures under a millimetre in length (and its tail is just four times as long), it was decided not to display a real specimen but an enlarged model. This is just one of the wonderful invertebrate models created especially for our museum.
