Luidia ciliaris

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Geographic Range

Located in parts of the Mediterranean Sea and the Atlantic ocean, these starfish can withstand both tropical and temperate or subboreal environments. They are most frequently found on the coast of Europe, including the British Isles, and have been seen as far north as the Shetlands, and as far south as Cape Verde. (B. E. Piction Co., 1996; Grzimek, 1972; Nichols and Cooke, 1971; Parker, 1982)

Habitat

The areas on the shores where Luidia ciliaris is native tend to be rough, sandy and shallow. The star lies scarcely burried under the sand. While Luidia ciliaris can live at depths ranging from four to four-hundred meters, it prefers the range of about fifty to one-hundred meters. These places are favorable to L. ciliaris because they provide a flourishing food source. (Grzimek, 1972)

  • Range depth
    4 to 400 m
    13.12 to 1312.34 ft

Physical Description

Luidia ciliaris is red-orange and has radial heptamerous symmetry in the adult stage. It consists of a small disk-shaped frame of plates (their mouth) surrounded by seven slighty-tapered tubular arms (each ranging in length from approximately 5-25 cm.) These tube arms lack suckers, and have double ampullae (two sets of terminal bulbs on each arm). Along each muscular arm is a band of long white spines. The arms are important to the creatures' attacks for food and escape from predators, and in almost all cases Luidia ciliaris is found, it either has an injured arm, or signs of regrowth of an arm. The internal systems of these animals have no intestine, ceca, or anus, and their gonads are arranged in a double series along the length of their arms. (B. E. Piction Co., 1996; Catala, 1986; Grzimek, 1972; Nichols and Cooke, 1971; Parker, 1982)

  • Range length
    14 to 60 cm
    5.51 to 23.62 in

Development

During the summer, new L. ciliaris zygotes are formed. These coelomates are part of one of the only two deuterosome phyla. They develop into fully functioning bipinnaria larvae after about three to four days. The larvae are very large and elaborate, and can reach up to thirty-five millimeters in length. These larvae live in their plankton feeding ground until they grow into a complete starfish (around four months from around July to October). (Grzimek, 1972; Howson and Piction, 1997)

Reproduction

The sexual reproduction of Luidia ciliaris is similar to the reproduction of most other starfish. The starfish gonads are arranged in a double series along the length of their arms. Fertilization of the females' eggs takes place in open water. The males' sperm is stimulated to be released following the egg release. To improve chances of the gametes meeting in the water, millions of eggs and sperm are released by each female and male. (Grzimek, 1972; Howson and Piction, 1997; Parker, 1982)

  • Breeding season
    Summer months: June
  • Average
    0.00 minutes

There is no parental involvement after release of gametes in this species.

  • Parental Investment
  • pre-fertilization
    • provisioning

Lifespan/Longevity

These starfish live from 2 to 3 years.

  • Typical lifespan
    Status: wild
    2 to 3 years

Behavior

Luidia ciliaris has both a high rate of movement as well as a high metabolic rate. It pushes itself up on its seven arms with its center vertically raised; this strange walking stance helps the starfish get lift-off which aids in its ability to move quickly. (Parker, 1982)

Communication and Perception

Their strange walking stances can be a warning to animals nearby that the starfish is on the chase or is about to attack. Asteroids in general can sense light, chemicals in the water, and respond to tactile stimulation. (Brusca and Brusca, 2003; Catala, 1986)

Food Habits

Similar to most starfishes, Luidia ciliaris is predatory. Foods eaten include heart urchins, brittle stars, the common starfish, the spiny starfish and many other enchinoderms.

The asteroid, which is present in low numbers throughout the year, forages in groups during the summer months. They are voracious carnivores, whose quick movements help them leap on top and devour their prey. Luidia ciliaris also has the ability to distort or even rupture the disk-shaped frame of plates of their mouths, allowing them to swallow very large prey. The seven-armed creature has been shown to prefer consuming brittle stars (ophiuroids) over other echinoderms in lab tests. As an example the ability of L. ciliaris to stretch its mouth, brittle stars can be up to almost twelve inches in diameter and can be fully injested by the carnivore. While known to feed on a variety of species of Echinodermata, L. ciliaris avoids those that secrete highly acidic mucus.

Larval Luidia ciliaris feed on plankton. (B. E. Piction Co., 1996; Monterey Bay Aquarium Foundation, 1999; Nichols and Cooke, 1971; Parker, 1982)

  • Animal Foods
  • aquatic crustaceans
  • other marine invertebrates
  • zooplankton

Predation

Luidia ciliaris escapes predators because of its inconspicuousness, its protective calcite skeleton, and because it is fairly fast moving (compared to most starfish). This species is also able to escape from predators because of its ability to regenerate lost body parts within a matter of a few weeks or months. (Hendler, et al., 1995)

Ecosystem Roles

Along the coast of the Western English Channel, Luidia ciliaris has a major role in the changing numbers of the sea shore's food chain. Luidia ciliaris shows a roughly inverse relationship to the abundance of Ophiothrix fragilis [brittle star]. In the last century, the numbers of this brittle star have steadily decreased while the number of Luidia ciliaris have increased in this area. (UK Marine Special Areas of Conservation, 2001)

Economic Importance for Humans: Positive

The seven-armed starfish plays an important role in the food chains of the North Atlantic and Mediterranean coasts of Europe and surrounding areas, helping keep the spiny brittle stars from overpopulating these waters.

  • Positive Impacts
  • research and education

Economic Importance for Humans: Negative

A food source of L. ciliaris, Ophiothrix fragilis, plays a role in cleaning sponges (Porifera) in the sea. These sponges are useful to humans in that they filter water as it moves through their bodies, and by decreasing brittle star numbers in some areas, the seven-armed animals are affecting the efficiency of the natural water cleaners.

Conservation Status

Contributors

Renee Sherman Mulcrone (editor).

Jessica Waldrop (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

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

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

external fertilization

fertilization takes place outside the female's body

fertilization

union of egg and spermatozoan

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

motile

having the capacity to move from one place to another.

planktivore

an animal that mainly eats plankton

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.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

zooplankton

animal constituent of plankton; mainly small crustaceans and fish larvae. (Compare to phytoplankton.)

References

B. E. Piction Co., 1996. "Echinodermata: Starfish, Sea Urchins etc." (On-line). Accessed October 2, 2001 at http://www.itsligo.ie/biomar/echinode/LUICIL.htm.

Brusca, R., G. Brusca. 2003. Invertebrates. Sunderland, Massachusetts: Sinauer Associates, Inc..

Catala, R. 1986. _Treasures of the Tropic Seas_, pg. 220. New York: Times Editions.

Grzimek, B. 1972. _Grzimek's Animal Life Encylopedia_: Vol. 3 Mollusks and Echinoderms, pg. 365, 377, 387. New York: Van Nostrand Reinhold Company.

Hendler, G., J. Miller, D. Pawson, P. Kier. 1995. _Sea Stars, Sea Urchins, and Allies_. Washington: Smithsonian Institution.

Howson, C., B. Piction. 1997. _The Species Directory of the Marine Fauna and Flora of the British Isles and Surrounding Seas_, pg. 359. North Ireland: Ulster Museum publication.

Monterey Bay Aquarium Foundation, 1999. "Brittle Star: {Ophiothrix spiculata}" (On-line). Accessed October 3, 2001 at http://www.mbayaq.org/efc/living_species/default.asp?hOri=1&inhab=142.

Nichols, D., J. Cooke. 1971. _The Oxford Book of Invertabrates_, pg. 181. New York: Oxford University Press.

Parker, S. 1982. _Synopsis and Classification of Living Organisms_: Vol. 2, pg. 796. New York: McGraw-Hill Book Co..

UK Marine Special Areas of Conservation, 2001. "The Western English Channel: Changes in Predation Intensity" (On-line). Accessed 12/10/04 at http://www.ukmarinesac.org.uk/communities/subtidal-brittlestar/bs4_1.htm.