Ectopleura larynxRinged tubularia

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Geographic Range

This species is common in the British isles, in the seas surrounding Great Britain, and in the Americas (Murphy, 1967).

Habitat

This species is usually found attached to floating buoys, mussel shells, rocks, rocky hangovers, and seaweed at low tide (Nichols, 1971). They can also be found on harbor pins and sunken rope (Grzimek, 1972). These are found in strong currents. Tubularia are rarely found alone, but almost always found in colonies of other hydroids (Murphy, 1967). (Grzimek, 1972; Murphy, 1967; Nichols, 1971)

Physical Description

Like all Cnidarians, this species is radially symmetrical, has no anus, and has tissue level of organization (Banister & Campbell 1985). The Tubularia has both polyp and medusa stages; however, the medusa remain attached to the polyp parent. That is to say, there is no free-living medusa form. Turbularia larynx is a very small animal, with a total length of about 2-3cm. It has two distinct rings of tentacles, one around its mouth and the other at the base of the head. In between these two rings, are the gonophores, or the sexual buds of the animal. These animals are very rich in color, usually a pink or red (Murphy, 1967).

Reproduction

During the summer time, swimming sperm are released into the water and attracted to female reproductive structures by means of a chemical substance. Internal fertilization occurs in the female medusoids. The fertilized eggs develop into actinula (Murphy, 1967). These larvae develop directly into a new polyp (Ricketts, et al 1948). So, although the medusa are attached to the polyp, the life cycle resembles the typical Cnidarian one with the polyp reproducing asexually and the medusa producing egg and sperm.

  • Parental Investment
  • no parental involvement

Behavior

Because this species is sessile throughout most of its life, the only behavior that exists is filter feeding and reproduction, which have already been described.

Food Habits

Because there are no free-living medusa and the dominant stage is a polyp, the tentacles of the Tubularia are used to gather food from the water. Most of the food gathered is plankton and sediment in the water (Coleman 1991).

Economic Importance for Humans: Positive

There are no positive effects of this species on human beings.

Economic Importance for Humans: Negative

There are no negative effects of this species on human beings, except for the possible negative effects of their presence as they anchor themselves on solid objects in the water. This would probably be more of a problem with aesthetics.

Conservation Status

Contributors

Alina Somodevilla (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.

Glossary

Atlantic Ocean

the body of water between Africa, Europe, the southern ocean (above 60 degrees south latitude), and the western hemisphere. It is the second largest ocean in the world after the Pacific Ocean.

World Map

coastal

the nearshore aquatic habitats near a coast, or shoreline.

ectothermic

animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature

native range

the area in which the animal is naturally found, the region in which it is endemic.

radial symmetry

a form of body symmetry in which the parts of an animal are arranged concentrically around a central oral/aboral axis and more than one imaginary plane through this axis results in halves that are mirror-images of each other. Examples are cnidarians (Phylum Cnidaria, jellyfish, anemones, and corals).

saltwater or marine

mainly lives in oceans, seas, or other bodies of salt water.

References

Banister, K., A. Campbell. 1985. The Encyclopedia of Aquatic Life. New York: Facts on File Publishing.

Coleman, N. 1991. Encyclopedia of Marine Animals. London: Blandford.

Grzimek, B. 1972. Grzimek's Animal Life Encyclopedia, Volume 1 Lower Animals. New York: Von Nostrand Reinhold Company.

Murphy, R. 1967. The Larousse Encyclopedia of Animal Life. New York: McGraw-Hill Book Company.

Nichols, D. 1971. The Oxford Book of Invertebrates. Oxford: Oxford University Press.

Ricketts, , Calvin, Hedgpeth. 1948. Between Pacific Tides.