Larvacea
Larvaceans (Class Appendicularia) are solitary, free-swimming tunicates found throughout the world's oceans. Like most tunicates, appendicularians are filter feeders. Unlike most other tunicates, they live in the pelagic zone, specifically in the upper sunlit portion of the ocean (photic zone) or sometimes deeper. They are transparent planktonic animals, generally less than 1 cm (0.39 in) in body length (excluding the tail).
Biology
The appendicularian body shape resembles that of the tadpole-like larvae of most tunicates. Like a common tunicate larva, the adult appendicularian form has a discrete trunk and tail. Evolution by retaining juvenile traits as an adult is known as neoteny.
Like most tunicates, appendicularians feed by drawing particulate food matter into their pharyngobranchial region, where food particles are trapped on a mucus mesh produced by the pharynx and drawn into the digestive tract. The mucus mesh lies over two clefts in the pharynx, one on either side, rather than the much larger number of clefts found in most other tunicates. Furthermore, the clefts, and the anus open directly to the outside, so the animal lacks the atrium and atrial siphon found in related classes.
Appendicularia (plant)
Appendicularia DC. is a botanic genus of the family Melastomataceae.
Species
The genus has two species:
References
External links
Podcasts:
