''Chondrus crispus''—commonly called Irish moss or carrageenan moss (Irish ''carraigín'', "little rock")—is a species of

red algae Red algae, or Rhodophyta (, ; ), make up one of the oldest groups of eukaryotic algae. The Rhodophyta comprises one of the largest Phylum, phyla of algae, containing over 7,000 recognized species within over 900 Genus, genera amidst ongoing taxon ...

which grows abundantly along the rocky parts of the

Atlantic The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...

coasts of Europe and North America. In its fresh condition it is soft and cartilaginous, varying in color from a greenish-yellow, through red, to a dark purple or purplish-brown. The principal constituent is a mucilaginous body, made of the polysaccharide

carrageenan Carrageenans or carrageenins ( ; ) are a family of natural linear sulfation, sulfated polysaccharides. They are extracted from red algae, red edible seaweeds. Carrageenans are widely used in the food industry, for their gelling, thickening, an ...

, which constitutes 55% of its dry weight. The organism also consists of nearly 10% dry weight protein and about 15% dry weight mineral matter, and is rich in

iodine Iodine is a chemical element; it has symbol I and atomic number 53. The heaviest of the stable halogens, it exists at standard conditions as a semi-lustrous, non-metallic solid that melts to form a deep violet liquid at , and boils to a vi ...

and

sulfur Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...

. When softened in water it has a sea-like odour. Because of the abundant cell wall polysaccharides, it will form a jelly when boiled, containing from 20 to 100 times its weight of water.

Description

''Chondrus crispus'' is a relatively small sea alga, reaching up to a little more than in length. It grows from a discoid holdfast and branches four or five times in a dichotomous, fan-like manner. The morphology is highly variable, especially the broadness of the thalli. The branches are 2–15 mm broad and firm in texture, and the color ranges from bright green towards the surface of the water, to deep red at greater depths. The

gametophyte A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the se ...

s (see below) often show a blue

iridescence Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear gradually to change colour as the angle of view or the angle of illumination changes. Iridescence is caused by wave interference of light in microstru ...

at the tip of the fronds and fertile sporophytes show a spotty pattern. '' Mastocarpus stellatus'' (Stackhouse) Guiry is a similar species which can be readily distinguished by its strongly channelled and often somewhat twisted thalli. Irish moss undergoes an alternation of generation lifecycle common in many species of algae. The two distinct stages are the sexual

haploid Ploidy () is the number of complete sets of chromosomes in a cell (biology), cell, and hence the number of possible alleles for Autosome, autosomal and Pseudoautosomal region, pseudoautosomal genes. Here ''sets of chromosomes'' refers to the num ...

stage and the asexual

diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Here ''sets of chromosomes'' refers to the number of maternal and paternal chromosome copies, ...

sporophyte A sporophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the biological life cycle, life cycles of plants and algae. It is a diploid multicellular organism which produces asexual Spo ...

stage. In addition, a third stage – the carposporophyte – is formed on the female gametophyte after fertilization. The male and female gametophytes produce gametes which fuse to form a diploid carposporophyte, which forms carpospores, which develops into the sporophyte. The sporophyte then undergoes

meiosis Meiosis () is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, the sperm or egg cells. It involves two rounds of division that ultimately result in four cells, each with only one c ...

to produce haploid tetraspores (which can be male or female) that develop into gametophytes. The three stages (male, female, and sporophyte) are difficult to distinguish when they are not fertile; however, the gametophytes often show a blue iridescence.

Distribution

''Chondrus crispus'' is commonly found along the shores of Ireland and the coast of Europe including

Iceland Iceland is a Nordic countries, Nordic island country between the Atlantic Ocean, North Atlantic and Arctic Oceans, on the Mid-Atlantic Ridge between North America and Europe. It is culturally and politically linked with Europe and is the regi ...

, the

Faroe Islands The Faroe Islands ( ) (alt. the Faroes) are an archipelago in the North Atlantic Ocean and an autonomous territory of the Danish Realm, Kingdom of Denmark. Located between Iceland, Norway, and the United Kingdom, the islands have a populat ...

, western

Baltic Sea The Baltic Sea is an arm of the Atlantic Ocean that is enclosed by the countries of Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland, Russia, Sweden, and the North European Plain, North and Central European Plain regions. It is the ...

to southern Spain. It is found on the Atlantic coasts of Canada and recorded from California in the United States to Japan. However, any distribution outside the Northern Atlantic needs to be verified. There are also other species of the same genus in the Pacific Ocean, for example, ''C. ocellatus'' Holmes, ''C. nipponicus'' Yendo, ''C. yendoi'' Yamada ''et'' Mikami, ''C. pinnulatus'' (Harvey) Okamura and ''C. armatus'' (Harvey) Yamada ''et'' Mikami.Hu, Z., Critchley, A.T., Gao T, Zeng X, Morrell, S.L. and Delin, D. 2007 Delineation of Chondrus (Gigartinales, Florideophyceae) in China and the origin of C. crisps inferred from molecular data. Marine Biology Research, 3: 145-154

Ecology

''Chondrus crispus'' is found growing on rock from the middle intertidal zone into the subtidal zone, all the way to the ocean floor. It is able to survive with minimal sunlight. ''C. crispus'' is susceptible to infection from the oomycete '' Pythium porphyrae''.

Uses

''C. crispus'' is an industrial source of

commonly used as a thickener and stabilizer in milk products, such as

ice cream Ice cream is a frozen dessert typically made from milk or cream that has been flavoured with a sweetener, either sugar or an alternative, and a spice, such as Chocolate, cocoa or vanilla, or with fruit, such as strawberries or peaches. Food ...

and processed foods. In Europe, it is indicated as E407 or E407a. It may also be used as a thickener in calico printing and paper marbling, and for fining beer. Irish moss is frequently used with ''Mastocarpus stellatus'' (''Gigartina mamillosa''), ''Chondracanthus acicularis '' (''G. acicularis''), and other seaweeds, which are all commonly found growing together. Carrageenan may be extracted from tropical seaweeds of the genera '' Kappaphycus'' and '' Eucheuma''.

Scientific interest

''C. crispus'', compared to most other seaweeds, is well-investigated scientifically. It has been used as a model species to study

photosynthesis Photosynthesis ( ) is a system of biological processes by which photosynthetic organisms, such as most plants, algae, and cyanobacteria, convert light energy, typically from sunlight, into the chemical energy necessary to fuel their metabo ...

, carrageenan

biosynthesis Biosynthesis, i.e., chemical synthesis occurring in biological contexts, is a term most often referring to multi-step, enzyme-Catalysis, catalyzed processes where chemical substances absorbed as nutrients (or previously converted through biosynthe ...

, and stress responses. The nuclear genome was sequenced in 2013. The genome size is 105 Mbp and is coding for 9,606 genes. It is characterised by relatively few genes with very few

intron An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word ''intron'' is derived from the term ''intragenic region'', i.e., a region inside a gene."The notion of the cistron .e., gen ...

s. The genes are clustered together, with normally short distances between genes and then large distances between groups of genes.

References

External links

AlgaeBase: Chondrus crispus

''Chondrus crispus''.

* Irish Moss industry on Prince Edward Islan

Sea Moss Market Report
{{Authority control Edible algae Gigartinaceae Flora of Jamaica Demulcents Taxa named by John Stackhouse Flora without expected TNC conservation status Lithophytes