Codium tomentosum
Encyclopedia
Codium tomentosum is a species
of green seaweed in the family
Codiaceae
. Its common names include velvet horn and spongeweed.
of C. tomentosum is saucer-shaped and has closely woven strands giving it a uniform appearance. The thallus or frond has a dichotomous
, much branched structure with thin branches, each with a circular cross section. It grows to 30 cm (12 in) in length and is spongy, with the texture of felt. It is covered with colourless hairs which are visible when it is submerged.
from the British Isles
southwards to the Azores
and Cape Verde
. It has also been recorded around the coasts of Africa and in various other parts of the world. The type locality is England. It is found on exposed rocks in deep rock pools
on the lower shore.
, has been spreading to various parts of the world, and a study was undertaken in 2003 in Guernsey
to see whether it was displacing or even eliminating C. tomentosum from the island. It was found that, on the contrary, the native species was still thriving on the lower shore and that C. fragile subsp. tomentosoides was restricted to rock pools in the upper mid-littoral region.
A similar study undertaken in 2000 on exposed shores in western Ireland
showed that, as compared to thirty years earlier, C. fragile subsp. tomentosoides had decreased while C. fragile subsp. atlanticum
had increased. The native C. tomentosum had maintained its population size and not been displaced.
The sea slug Elysia viridis
(the "sap-sucking slug") feeds on C. tomentosum and C. fragile and has a symbiotic
relationship with them. When the fluids from the algae are ingested, the chloroplast
s remain intact and photosynthetically
active in the digestive diverticula
of the slug for some days. They continue to synthesize sugars which the slug then metabolises. The activity of the chloroplasts degenerates over time and they need to be constantly replaced by further consumption of Codium spp.
named tomentine has been isolated by affinity chromatography
from C. tomentosum. It shows N-acetylglucosamine
-specific activity and has been found to be rich in glycine
, threonine
and valine
.
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 green seaweed 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...
Codiaceae
Codiaceae
In taxonomy, the Codiaceae are a family of algae, specifically of the Bryopsidales....
. Its common names include velvet horn and spongeweed.
Description
The holdfastHoldfast
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. ...
of C. tomentosum is saucer-shaped and has closely woven strands giving it a uniform appearance. The thallus or frond has a dichotomous
Dichotomy
A dichotomy is any splitting of a whole into exactly two non-overlapping parts, meaning it is a procedure in which a whole is divided into two parts...
, much branched structure with thin branches, each with a circular cross section. It grows to 30 cm (12 in) in length and is spongy, with the texture of felt. It is covered with colourless hairs which are visible when it is submerged.
Distribution and habitat
C. tomentosum is native to the north east Atlantic OceanAtlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
from the British Isles
British Isles
The British Isles are a group of islands off the northwest coast of continental Europe that include the islands of Great Britain and Ireland and over six thousand smaller isles. There are two sovereign states located on the islands: the United Kingdom of Great Britain and Northern Ireland and...
southwards to the Azores
Azores
The Archipelago of the Azores is composed of nine volcanic islands situated in the middle of the North Atlantic Ocean, and is located about west from Lisbon and about east from the east coast of North America. The islands, and their economic exclusion zone, form the Autonomous Region of the...
and Cape Verde
Cape Verde
The Republic of Cape Verde is an island country, spanning an archipelago of 10 islands located in the central Atlantic Ocean, 570 kilometres off the coast of Western Africa...
. It has also been recorded around the coasts of Africa and in various other parts of the world. The type locality is England. It is found on exposed rocks in deep rock pools
Tide pool
Tide pools are rocky pools by oceans that are filled with seawater. Many of these pools exist as separate entities only at low tide.Tide pools are habitats of uniquely adaptable animals that have engaged the special attention of naturalists and marine biologists, as well as philosophical...
on the lower shore.
Ecology
The related taxon, C. fragile subsp. tomentosoidesCodium fragile
Codium fragile, also known as Green sea fingers, Dead man's fingers, felty fingers, felt-alga, Green sponge and Green fleece is an invasive species of seaweed in the family Codiaceae....
, has been spreading to various parts of the world, and a study was undertaken in 2003 in Guernsey
Guernsey
Guernsey, officially the Bailiwick of Guernsey is a British Crown dependency in the English Channel off the coast of Normandy.The Bailiwick, as a governing entity, embraces not only all 10 parishes on the Island of Guernsey, but also the islands of Herm, Jethou, Burhou, and Lihou and their islet...
to see whether it was displacing or even eliminating C. tomentosum from the island. It was found that, on the contrary, the native species was still thriving on the lower shore and that C. fragile subsp. tomentosoides was restricted to rock pools in the upper mid-littoral region.
A similar study undertaken in 2000 on exposed shores in western Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...
showed that, as compared to thirty years earlier, C. fragile subsp. tomentosoides had decreased while C. fragile subsp. atlanticum
Codium fragile
Codium fragile, also known as Green sea fingers, Dead man's fingers, felty fingers, felt-alga, Green sponge and Green fleece is an invasive species of seaweed in the family Codiaceae....
had increased. The native C. tomentosum had maintained its population size and not been displaced.
The sea slug Elysia viridis
Elysia viridis
Elysia viridis or the sap-sucking slug is a small-to-medium-sized species of green sea slug, a marine opisthobranch gastropod mollusc in the family Placobranchidae....
(the "sap-sucking slug") feeds on C. tomentosum and C. fragile and has a symbiotic
Endosymbiont
An endosymbiont is any organism that lives within the body or cells of another organism, i.e. forming an endosymbiosis...
relationship with them. When the fluids from the algae are ingested, the chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...
s remain intact and photosynthetically
Photosynthesis
Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...
active in the digestive diverticula
Diverticulum
A diverticulum is medical or biological term for an outpouching of a hollow structure in the body. Depending upon which layers of the structure are involved, they are described as being either true or false....
of the slug for some days. They continue to synthesize sugars which the slug then metabolises. The activity of the chloroplasts degenerates over time and they need to be constantly replaced by further consumption of Codium spp.
Research
A lectinLectin
Lectins are sugar-binding proteins that are highly specific for their sugar moieties. They play a role in biological recognition phenomena involving cells and proteins. For example, some viruses use lectins to attach themselves to the cells of the host organism during infection...
named tomentine has been isolated by affinity chromatography
Affinity chromatography
Affinity chromatography is a method of separating biochemical mixtures and based on a highly specific interaction such as that between antigen and antibody, enzyme and substrate, or receptor and ligand.-Uses:Affinity chromatography can be used to:...
from C. tomentosum. It shows N-acetylglucosamine
N-Acetylglucosamine
N-Acetylglucosamine is a monosaccharide derivative of glucose. It is an amide between glucosamine and acetic acid...
-specific activity and has been found to be rich in glycine
Glycine
Glycine is an organic compound with the formula NH2CH2COOH. Having a hydrogen substituent as its 'side chain', glycine is the smallest of the 20 amino acids commonly found in proteins. Its codons are GGU, GGC, GGA, GGG cf. the genetic code.Glycine is a colourless, sweet-tasting crystalline solid...
, threonine
Threonine
Threonine is an α-amino acid with the chemical formula HO2CCHCHCH3. Its codons are ACU, ACA, ACC, and ACG. This essential amino acid is classified as polar...
and valine
Valine
Valine is an α-amino acid with the chemical formula HO2CCHCH2. L-Valine is one of 20 proteinogenic amino acids. Its codons are GUU, GUC, GUA, and GUG. This essential amino acid is classified as nonpolar...
.