The northern red anemone or dahlia anemone, Urticina felina, is a marine invertebrate found in the north Atlantic Ocean, the North Sea and the Baltic Sea. Synonyms include Tealia crassicornis (Müller, 1776), Tealia felina (Linnaeus, 1761), and Urticina crassicornis (Müller, 1776). The colour is variable. The sea anemone lives attached to rock on the seabed from the lower tidal limit down to a depth of 100 m and also attached to other organisms. It eats small fish and crustaceans, immobilizing its prey by firing groups of stinging cells (cnidae) into them.

Description

The base is up to 120mm across and firmly adherent to the rock. Deep sea specimens are usually larger than inshore ones. The column is usually shorter than its diameter and its surface is covered in verrucae. There is a parapet at the top where the verrucae tend to be organised into rows. The verrucae usually have bits of gravel and debris attached to them and the contracted anemone has the appearance of a rounded hummock of gravel. The disc is not broader than the parapet and has up to 160 short tentacles arranged in multiples of ten. The colour is very variable; some individuals have a red column with green blotches, grey verrucae and greyish banded tentacles; others have a red column and disc with grey verrucae and white tentacles. The tentacles are often banded and in many individuals there are thin red lines on the disc visible between the tentacles.^[2]

Distribution

U felina is found in the Arctic Ocean, the Baltic Sea, the North Sea and the northern Atlantic Ocean as far south as the Bay of Biscay and the Gulf of Maine.^[1]

Habitat

U felina is found on rocks and boulders from the lower shore down to depths of 100 metres. It occurs in rock pools, in crevices and gullies, among the holdfasts of Laminaria spp., in caves and partly buried in gravel.^[2]

References

• Wildlife Fact File, 1996, Card #15

This class Anthozoa related article is a stub. You can help Wikipedia by expanding it. v t e

Urticina crassicornis is a large and common intertidal and subtidal sea anemone formerly known as Tealia crassicornis and commonly referred to as the Christmas Anemone. Its habitat includes a large portion of global coastal areas and it lives a solitary life for up to 80 years of age.^[1]

Description

Urticina crassicornis is biradially symmetrical and ranges from 2 - 12.7 cm tall with a width of 1 - 7.6 cm. This sea anemone has a solid basal plate which is always flat. Its column can be olive green with or without red spots; solid red; cream; or brown, always with small, inconspicuous tubercles but no acontia. Its tubercles are not white and do not usually accumulate bits of sand, gravel and shell. The tentacles, superior of the column and usually 100 in number, are green to opaque cream with red and white striations and semi-transparent when extended. The tentacles are conical, thick and blunt and arranged in 3 - 5 circular rings around the oral disc. The oral disc has no white striations and usually has the same color scheme as the tentacles.^[1][2]

Geographical Range and Habitat

In the Pacific Ocean, Urticina crassicornis ranges from intertidal and subtidal zones of the Pribilof Islands, Alaska to Monterey, California. In the Atlantic Ocean, it is found in intertidal and subtidal zones ranging from the Arctic Ocean above Newfoundland, Canada to Cape Cod, Massachusetts and also along the coasts of Western Europe. In the state of Washington this sea anemone more commonly frequents the Puget Sound compared to the Pacific Ocean front. It is found in a lower intertidal, upper subtidal zone - 30 m deep, inhabiting well protected and shaded areas. Urticina crassicornis is a benthic and sessile organism, firmly attached only to hard substrata. This sea anemone is frequently found on docks, wood pilings, and under large rock outcroppings.^[1]

Feeding

A non-selective and opportunistic predator, Urticina crassicornis, may feed on crabs, sea urchins, mussels, gastropods, chitons, barnacles, fish, and sometimes sea stars and stranded jellies. A peculiar prey, the sun star, Pycnopodia helianthoides commonly known as the "Sunflower Star", is found in Washington state and has a size much greater than U. crassicornis, sometimes ranging up to 5 ft. in length.^[3] This anemone exhibits both intracellular and extracellular digestion. Food is caught within the tentacles which then move the prey towards the oral disc.^[2][4]

Predators, Parasites, and Protection

In the Pacific, certain species of both Asteroidea and Gastropoda are known predators of this anemone. Demasterias imbricata (Asteroidea) and Aeolidia papillosa (Gastropoda) are two notably frequent predator species. Urticina crassicornis senses predation through a simple nerve net spanning along its column and tentacle walls. For protection, U. crassicornis inverts its tentacles to the inside of its body column and projects nematocysts. Minimal locomotion is possible if the organism is sensing extreme danger. Some species of amphipods are parasites of U. crassicornis living within its body cavity for the benefits of housing and food. These species are not affected by the nematocysts of U. crassicornis, which has the ability to kill other species of crustacean.^[5][6]

Reproduction

Urticina crassicornis produces by both asexual and sexual reproduction. In the Atlantic populations, eggs and sperm are held and fertilized within the body column. The young are brooded between the mesenteries of the body and are emitted as smallish, well developed, young anemones. Spawning occurs in the spring amongst Puget Sound populations, when eggs (yolky, 0.7 mm in diameter) and sperm are released into the sea for fertilization. Urticina crassicornis's major sperm chromosomal proteins have been found to be two specialized histone H1 proteins which indicate a strong relation to the chromosomal proteins of bird and amphibians.^[7] After fertilization, a solid and ciliated blastula is created due to superficial cleavage. Six days following fertilization, a cone-shaped and benthic, larval planula develops. These planula then settle onto small rocks or the empty tubes of some annelid worms and rapidly develop into small anemones. 12 days after settlement, 8 tentacles appear. Further growth is slow – two months after settlement, 12 tentacles appear and the anemone is 0.88 mm in diameter; one year after settlement, the anemone has 35 tentacles and is 10 mm in diameter. Growth is proportional to food intake, not age. When starved, this anemone can stay alive for 9 months but does not grow. Urticina crassicornis is sexually mature with a diameter of 10 – 15 mm, being at least one year old.^[1]

Footnotes

References

1. Nybakken, James W. Diversity of the Invertebrates. Dubuque, IA: Times Mirror Higher Education Group, Inc., 1996.
2. Abbot, Donald P., Hadderlie, Eugene C., Morris, Robbert H. Intertidal Invertebrates of California. Stanford, CA: Stanford University Press, 1980.
3. Kozloff, Eugene N. Marine Inveretebrates of the Pacific Northwest. Seattle, WA: University of Washington Press, 1996.
4. Cowles, David. Urticina crassicornis. Walla-Walla, WA: Walla-Walla University, 2005.
5. Ausio, Juan, Rocchini, Corinne, Zhang, Fan. Two Specialized Histone H1 proteins are the major sperm of the sea anemone Urticina (Tealia) crassicornis. Victoria, BC: Department of Biochemistry and Microbiology, University of Victoria, 1995
6. Chia, Fu-Shiang, Spaulding, James G. Development and Juvenile growth of the sea anemone, Tealia Crassicornis. Marine Biological Laboratory, 1972.
7. Verill, A.E. On the Parasitic Habits of Crustacea. Chicago, IL: The University of Chicago Press, 1869.
8. Markovich, Karlee. Urticina crassicornis. Juneau, AK: University of Alaska Southeast, 2002.

Urticina columbiana, common names crusty red anemone, columbia sand anemone, sand anemone, and the sand-rose anemone,^[1] is a species of sea anemone in the family Actiniidae.^[2][3]

Description

This species can grow to 25 cm high and can reach a diameter of 1 metre, making it one of the largest species of anemone.^[4] The tentacles are long and slender, taking the shape of a red column. The tubercles on the column are big and rough, having a white colour. They are organized in circular rows which protrude from the column. Unlike other species which may accumulate matter, the tubercles do not attach to ocean debris such as bits of shell. The column is red in colour.^[3]

No special spherules are present around the external rim of the oral disk beyond the tentacles.^[3]

Distribution

Urticina columbiana species occurs in the Pacific Ocean from Vancouver Island to Baja California.^[3]

Habitat

This species is found between the subtidal zone to a depth of 45 metres. It normally lives among shells, in soft sand or mud. It is usually partially buried, with tubercles mostly under the sea floor.^[3]

Symbionts

The candy stripe shrimp (Lebbeus grandimanus), a symbiont of Urticina columbiana

The candy stripe shrimp (Lebbeus grandimanus) is one of the symbionts of this species.^[3]

References

• Kozloff, Eugene N., 1987. Marine Invertebrates of the Pacific Northwest. University of Washington Press, Seattle, WA. 511 pp. ISBN 0-295-96530-4

• Harbo, Rick M., 1999, 2011. Whelks to Whales: Coastal Marine Life of the Pacific Northwest. Harbour Publishing, Madeira Park, BC, Canada. Paperback, 245 pp. ISBN 1-55017-183-6.

• Lamb, Andy and Bernard P. Hanby, 2005. Marine Life of the Pacific Northwest. A Photographic Encyclopedia of Invertebrates, Seaweeds and Selected Fishes. 398 pp. Harbour Publishing. ISBN 1-55017-361-8.