Tunicates: Difference between revisions
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Tunicates have a brief larval stage in which their main goal is to find a place to live out their adult life. During the larval stage, the tunicates does not have a mouth and doesn't feed. After several days, the larval will attach to a surface using anterior adhesive papillae. As the larva metamorphoses into an adult, the larval tail is resorbed, providing food to the adult tunicate. Free-swimming tunicates metamorphose without attaching to a surface. [http://www.britannica.com/animal/tunicate] | Tunicates have a brief larval stage in which their main goal is to find a place to live out their adult life. During the larval stage, the tunicates does not have a mouth and doesn't feed. After several days, the larval will attach to a surface using anterior adhesive papillae. As the larva metamorphoses into an adult, the larval tail is resorbed, providing food to the adult tunicate. Free-swimming tunicates metamorphose without attaching to a surface. [http://www.britannica.com/animal/tunicate] | ||
[[File:metamorphoses.png| | [[File:metamorphoses.png|200px]] | ||
For the most part, tunicates are hermaphrodites. They can reproduce both sexually and asexually by budding. Tunicates, like most hermaphroditic animals, try to avoid self-fertilizing. Fertilization often occurs in the water surrounding the tunicates, and development occurs in both the surrounding water and in the female tunicates. | For the most part, tunicates are hermaphrodites. They can reproduce both sexually and asexually by budding. Tunicates, like most hermaphroditic animals, try to avoid self-fertilizing. Fertilization often occurs in the water surrounding the tunicates, and development occurs in both the surrounding water and in the female tunicates. | ||
Revision as of 16:05, 2 March 2016
Tunicates
Forms of Tunicates
Solitary Tunicates – some tunicates live alone
Colonial Tunicates – tunicates are able to bud off individual tunicates and grow colonies. These colonies are similar in resemblance to encrusting marine animals like sponges, but upon closer look they have the same structures as solitary tunicates.
Drifting Tunicates – Some tunicates never attach to an object or surface, but live as planktonic drifters. They use their siphons for movement.
Comparison of Tunicates and Vertebrates
Tunicates belong to the phylum Urochordata, which is closely related to phylum Chordata that includes all vertebrates.
Tunicates and vertebrates both share a notochord, dorsal hollow, and a nerve cord. These characteristics are only seen in embryonic development of tunicates. Since tunicates are sedentary they lose some parts of their skeletal anatomy. This allows them to attach to their chosen spot, this will then lead them to grow the necessary structures to live an adult life. [1]
Sensory Neural Structures
Anatomy of Tunicates
Tunic- tissue that provides protection from predators.
Heart- pumps blood in a different matter. For a few minutes it will pump in one direction and then pump in reverse for another few minutes.
Siphon/ in and out- allows for the animal to feed
Pharynx- allows for the animal to filter food and dissolved oxygen.
Reproduction and Life Cycle
Tunicates have a brief larval stage in which their main goal is to find a place to live out their adult life. During the larval stage, the tunicates does not have a mouth and doesn't feed. After several days, the larval will attach to a surface using anterior adhesive papillae. As the larva metamorphoses into an adult, the larval tail is resorbed, providing food to the adult tunicate. Free-swimming tunicates metamorphose without attaching to a surface. [2]
For the most part, tunicates are hermaphrodites. They can reproduce both sexually and asexually by budding. Tunicates, like most hermaphroditic animals, try to avoid self-fertilizing. Fertilization often occurs in the water surrounding the tunicates, and development occurs in both the surrounding water and in the female tunicates.
Diet and Digestive System
Tunicates mainly eat phytoplankton and other small organisms in the water. Cilia at the entrance of the pharynx
Distribution and Abundance
Tunicates can be found in ocean waters from polar regions to the tropics. They can be found floating in the ocean water or attached to rocks, docks, ship hulls, and other hard surfaces.
Evolution of Tunicates
Ascidiacea, Thaliacea, Larvacea
Fast evolving
Loss of Genes- Some are expressed in similar organisms while others are missing genes.
Larval Stage- Tadpole like stage where are similarities with vertebrates are present.
Works Cited
http://depts.washington.edu/fhlk12/links/StudentProjects/Tun.biology.html
Lemaire P, Piette J. 2015 Tunicates: exploring the sea shores and roaming the open ocean. A tribute to Thomas Huxley. Open Biol. 5: 150053. http://dx.doi.org/10.1098/rsob.150053