Class Anthozoa
(sea anemones and corals)
Major Attributes:
- Tropical marine habitat.
- Mouth surrounded by tentacles with nematocysts.
- Partioned gastrovascular cavity.
- Secretes nonliving substance around outside of body to support and protect soft body tissues.
- Reproduces sexually by producing a free-swimming larva (planula) or
asexually by budding or fission.
- Cylindrical, with radial symmetry.
Description:
Anthozoans are divided into
two sub-classes, the Alcyonariae
and the Zoanthariae. The Alcyonariae have eight mesenteries and
branching tentacles. The Zoanthariae have mesenteries in
multiples of six and unbranching tentacles. Anthozoans include coral,
sea fans, sea pansies and sea anemones. The sea anemones have a
cylindrical, stout, muscular body while the sea fans and coral have a
thin, slightly muscular body. All possess a smooth, slimy basal disc. This disc is used for sliding during migration
or for attaching to the subsratum. Anthozoans have special gland
cells scattered throughout the body that secrete digestive fluids. The stomadeum is lined with flagella, which
create a current in the body cavity. These currents remove waste and
help bring in food particles and oxygen. Some Anthozoans are hermaphroditic,
while other species have separate sexes.
Some other interesting facts:
- Anthozoans vary greatly in appearance. Many species are shades
of red, pink and purple, while others are blue, yellow, white and
orange. They range from less than half an inch to large
colonial sea pens that can exceed two feet.
- Anthozoans live singly or in colonies.
- Anthozoans have special glands that secrete digestive fluids.
Some have been known to digest extremely large fish.
- Anthozoans are found around reefs and shallow waters. Since
they help build coral reefs they have been valuable to scientists in
learning about the past climates of certain regions.
Some Pertinent Books Found in Lamson Library:
- Banister, Dr. Keith and Dr. Andrew Campbell. 1985. The
Encyclopedia of Aquatic Life. New York, NY: Facts On File.
- Bullough, W.S. 1958. Practical Invertebrate Anatomy. New
York: St. Martins Press.
(Christopher W. Benker, Fall 1994; edited B. Miller, Spring 1995)
