Aplidium solidum
Encyclopedia
Aplidium solidum is a species
of colonial
sea squirts, a tunicate in the family
Polyclinidae
. It is commonly known as the red ascidian or sea pork.
. The tunic is gelatinous but firm in consistency, 2 to 3 cm thick and a red or pink colour. The individual zooid
s are bright red, 12 mm long and arranged in small systems. There are usually 13 to 15 rows of gill-like perforations in the pharynx of each.
and it is also found in Australian waters. It occurs on the west coast of North America from British Columbia
south to California
where it is common on rocks, especially among the holdfast
s of kelp forest
s, and pilings. It occurs in the intertidal zone
and at depths down to 40 metres.
. Water is sucked into the interior of the organism through an oral aperture and then expelled through a larger one, common to all the zooids in the system. Phytoplankton
and other small organisms get trapped in mucus
threads secreted by the endostyle
.
This tunicate breeds in the spring and summer and broods its larva
e in its atrial cavity.
The nudibranch
, Hermissenda crassicornis
, feeds on this tunicate.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
of colonial
Colony (biology)
In biology, a colony reference to several individual organisms of the same species living closely together, usually for mutual benefit, such as stronger defense or the ability to attack bigger prey. Some insects live only in colonies...
sea squirts, a tunicate in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Polyclinidae
Polyclinidae
Polyclinidae is a family of tunicates in the order Enterogona. It describes a group of marine animals.-Genera:The World Register of Marine Species lists the following genera:*Aplidiopsis - Lahille, 1890 *Aplidium - Savigny, 1816 *Fragaroides...
. It is commonly known as the red ascidian or sea pork.
Description
Aplidium solidum is a compound tunicate forming sheets or slabs up to 20 cm across on rocks and other hard substratesSubstrate (biology)
In biology a substrate is the surface a plant or animal lives upon and grows on. A substrate can include biotic or abiotic materials and animals. For example, encrusting algae that lives on a rock can be substrate for another animal that lives on top of the algae. See also substrate .-External...
. The tunic is gelatinous but firm in consistency, 2 to 3 cm thick and a red or pink colour. The individual zooid
Zooid
A zooid or zoöid is a single animal that is part of a colonial animal. The zooids can either be directly connected by tissue or share a common exoskeleton...
s are bright red, 12 mm long and arranged in small systems. There are usually 13 to 15 rows of gill-like perforations in the pharynx of each.
Distribution
The type location of Aplidium solidum is Pemba Island, TanzaniaTanzania
The United Republic of Tanzania is a country in East Africa bordered by Kenya and Uganda to the north, Rwanda, Burundi, and the Democratic Republic of the Congo to the west, and Zambia, Malawi, and Mozambique to the south. The country's eastern borders lie on the Indian Ocean.Tanzania is a state...
and it is also found in Australian waters. It occurs on the west coast of North America from British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
south to California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
where it is common on rocks, especially among the holdfast
Holdfast
A holdfast is a root-like structure that anchors aquatic sessile organisms, such as seaweed, other sessile algae, stalked crinoids, benthic cnidarians, and sponges, to the substrate. ...
s of kelp forest
Kelp forest
Kelp forests are underwater areas with a high density of kelp. They are recognized as one of the most productive and dynamic ecosystems on Earth. Smaller areas of anchored kelp are called kelp beds....
s, and pilings. It occurs in the intertidal zone
Intertidal zone
The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...
and at depths down to 40 metres.
Biology
Aplidium solidum is a filter feederFilter feeder
Filter feeders are animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish and some sharks. Some birds,...
. Water is sucked into the interior of the organism through an oral aperture and then expelled through a larger one, common to all the zooids in the system. Phytoplankton
Phytoplankton
Phytoplankton are the autotrophic component of the plankton community. The name comes from the Greek words φυτόν , meaning "plant", and πλαγκτός , meaning "wanderer" or "drifter". Most phytoplankton are too small to be individually seen with the unaided eye...
and other small organisms get trapped in mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
threads secreted by the endostyle
Endostyle
An endostyle is a longitudinal ciliated groove on the ventral wall of the pharynx which produces mucus to gather food particles. It is found in urochordates and cephalochordates, and in the larvae of lampreys. It aids in transporting food to the esophagus. It is also called the hypopharyngeal groove...
.
This tunicate breeds in the spring and summer and broods its larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e in its atrial cavity.
The nudibranch
Nudibranch
A nudibranch is a member of what is now a taxonomic clade, and what was previously a suborder, of soft-bodied, marine gastropod mollusks which shed their shell after their larval stage. They are noted for their often extraordinary colors and striking forms...
, Hermissenda crassicornis
Hermissenda crassicornis
Hermissenda crassicornis is a species of small, brightly-colored, sea slug or nudibranch, a marine gastropod mollusk in the family Glaucidae.This species is also commonly known as the "opalescent sea slug."-Distribution:...
, feeds on this tunicate.