Sycon ciliatumciliated sponge

Geographic Range

Sycon ciliatum are marine sponges found world-wide, usually in shallow water, but rarely more than 150 meters deep. They are predominant in temperate regions. (Grzimek, 1972; Worheide, 1998)


Sycon ciliatum live in shallow marine waters, from the intertidal zone out into sublittoral depths. They are found on the underside of rocks in relatively protected areas among bryozoans, hydroids, and other organisms. (Harris, 1990; Worheide, 1998)

Physical Description

Sycon ciliata are creamy yellow in color and delicate-looking. Their bodies are arranged in the asconoid system, which is a simple tube with no folding of the outer body wall. They range from 1-3cm in height. Hairy, needle-like spines (called spicules) cover their bodies. The spicules surrounding the osculum opening are longer than those at the base of the body. Y-shaped tetraxon calcite spicules lining the spongocoel and triactine spiclules in the walls of the flagellated chambers form the supporting skeleton of the sponge. The spicules appear to lie in a jelly called mesohyl, a structureless jelly containing archaocytes, amoeboid cells, and others.

Internal flagellated tubes are responsible for water current. The tubes are arranged radially and have openings call apopyles. Apopyles open into a central cavity or the spongocoel. The spongocoel leads into the osculum, which has an adjustable diaphragm. The diaphragm is surrounded by large spicules. (Harris, 1990; Waller, et al., 1996; Worheide, 1998)


Reproduction occurs mainly sexually. The formation of female gametes occurs from choanocytes. Spermatogenesis occurs in spermatic cysts which form in the mesohyl. These cysts can form when cells of the choanocyte chamber are transformed to spermatogonia through withdrawl of their flagellum and mitosis. Sperm are released into the sea through the osculum. Choanocytes of another sponge trap sperm and retain it in a vacuole. The choanocyte then looses its collar and flagellum. The cell is now called a carrier cell. This cell migrates through the mesohyl to an ovum. The carrier cell enters the cytoplasm of the ovum.

Development of the larva takes place within the parent sponge. The parent sponge nourishes the blastula by means of trophic cells that pass into the blastula. The blastula then turns inside out so the flagella project outwards. Once the amphiblastula with a hollow central cavity, the larvae is set free to swim in the sea. Once the larvae settles, the flagella are withdrawn and the cells form a central mass. A pupae is formed when the external cells flatten and serete spicules. A cavity forms that will be the first flagellated chamber and then the spongocoel. Once this cavity forms, the sponge begins to take on the shape of a cylinder. (Bergquist, 1978; Harris, 1990; Simpson, 1984)


Sycon ciliatum can withstand movements of water and changes in tides. The hair-like covering of the calcite spicules holds water because of capillary action. This also prevents air from entering the chambers.

It is believed that the large fine spicules surrounding the diaphragm help separate the inhalent and exhalent currents. They may also prevent small predators such as amphipods, syllid worms, and polyclads from entering the spongocoel. (Harris, 1990)

Food Habits

Sycon ciliatum obtain food by filtering water through choanocytes. Water enters the incurrent canal. The canal is lined with pinacocytes and communicates with the flagellated chambers through small holes, the propsopyles, which open into an internal flagellated tube lined with choanocytes. Food particles are digested intracellularly. Nutrients are transported from choanocytes to other cells through amoeboids in the mesohyl. (Harris, 1990)

  • Plant Foods
  • algae

Economic Importance for Humans: Positive

While not reported specifically for Sycon ciliatum, some species of sponges produce toxins that inhibit the growth of surrounding individuals. These toxins are the topic of important research on nerve impulse transmission. Other sponges contain varieties of antibiotic substances and pigments that are important for medicinal purposes. (Banister and Campbell, 1985)

Economic Importance for Humans: Negative

This species does not affect humans in a negative manner.

Conservation Status

Like all marine life, Sycon ciliatum are affected by water pollution, temperature changes, and changes in water levels.

Other Comments

Sponges such as Sycon ciliatum are sometimes eaten by nudibranchs, chitons, sea stars, turtles, and some fish.

2000 years ago, sponges were considered plants. Aristotle was the first person to recognize the animal nature of sponges. However, it was not until a little over 200 years ago that the idea of sponges being animals was widely accepted. ("The Larousse Encyclopedia of Animal Life", 1967; Banister and Campbell, 1985)


Deidra Schelin (author), Southwestern University, Stephanie Fabritius (editor), Southwestern University.


Arctic Ocean

the body of water between Europe, Asia, and North America which occurs mostly north of the Arctic circle.

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

Pacific Ocean

body of water between the southern ocean (above 60 degrees south latitude), Australia, Asia, and the western hemisphere. This is the world's largest ocean, covering about 28% of the world's surface.

World Map


Referring to an animal that lives on or near the bottom of a body of water. Also an aquatic biome consisting of the ocean bottom below the pelagic and coastal zones. Bottom habitats in the very deepest oceans (below 9000 m) are sometimes referred to as the abyssal zone. see also oceanic vent.


the nearshore aquatic habitats near a coast, or shoreline.


an animal that mainly eats decomposed plants and/or animals


particles of organic material from dead and decomposing organisms. Detritus is the result of the activity of decomposers (organisms that decompose organic material).


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


union of egg and spermatozoan


a method of feeding where small food particles are filtered from the surrounding water by various mechanisms. Used mainly by aquatic invertebrates, especially plankton, but also by baleen whales.


An animal that eats mainly plants or parts of plants.


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.

internal fertilization

fertilization takes place within the female's body

intertidal or littoral

the area of shoreline influenced mainly by the tides, between the highest and lowest reaches of the tide. An aquatic habitat.


offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

native range

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


an animal that mainly eats plankton


structure produced by the calcium carbonate skeletons of coral polyps (Class Anthozoa). Coral reefs are found in warm, shallow oceans with low nutrient availability. They form the basis for rich communities of other invertebrates, plants, fish, and protists. The polyps live only on the reef surface. Because they depend on symbiotic photosynthetic algae, zooxanthellae, they cannot live where light does not penetrate.

saltwater or marine

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


non-motile; permanently attached at the base.

Attached to substratum and moving little or not at all. Synapomorphy of the Anthozoa


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


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).


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


1967. The Larousse Encyclopedia of Animal Life. New York: McGraw-Hill Book Co..

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

Bergquist, 1978. Sponges. Los Angeles: University of California Press.

Grzimek, B. 1972. Grzimek's Animal Life Encyclopedia; Vol. 1: Lower Animals. New York: Van Nostrand Reinhold Co..

Harris, V. 1990. Sessile Animals of the Sea Shore. New York: Chapman and Hall.

Simpson, T. 1984. The Cell Biology of Sponges. New York: Springer-Berlag.

Waller, G., M. Burchett, M. Dando. 1996. SeaLife: A Complete Guide to the Marine Environment. Washington, D.C.: Smithsonian Institution Press.

Worheide, G. 1998. "Gert Worheide's Site" (On-line). Accessed February 25, 2000 at