''Codium'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of edible green macroalgae (or

seaweed Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of ''Rhodophyta'' (red), '' Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...

) under the

order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...

Bryopsidales Bryopsidales is an order of green algae, in the class Ulvophyceae. It is a diverse group of mostly marine macroalgae. Characteristics The thallus is filamentous, highly branched, and may be packed into a mass. It is coenocytic, having multi-nu ...

. The genus name is derived from a Greek word that pertains to the soft texture of its

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

. One of the foremost experts on ''Codium'' taxonomy was Paul Claude Silva at the

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

. Silva was able to describe 36 species for the genus, and in honor of his work on ''Codium'', the species ''C. silvae'' was named after the late professor.

Taxonomy and nomenclature

This genus is the largest member of the algal family Codiaceae and consequently under order Bryopsidales and it currently has about 143 confirmed species and four (4) unresolved members. Stackhouse, unfortunately, failed to provide

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

specimens for ''C. tomentosum'' (type species) and some of its dichotomously branching congeners leading to misidentifications; P.C. Silva delineated ''C. tomentosum'', ''C. fragile'', and ''C. vermilara'' and established neotypes for each species to finally resolve this taxonomic blunder.

Morphology

Being a member of the order Bryopsidales, ''Codium'' is coenocytic and siphonous. Their spongy thallus is composed of a single, multinucleated, branched, tubular cell called siphon which terminates at a swollen end called the utricle. These siphons intertwine with each other to form the clear mesh-like center of the ''Codium'' thallus called the medulla while the utricles surround this central layer to form a green to dark-green palisade layer called the cortex. The genus has a wide variety of thalli forms: (1) mat-forming, the thalli encrusts and adheres to given a substrate using its medullary filaments; (2) spherical, the thalli forms a ball and is superficially attached to an area using rhizoidal filaments; and (4) erect thalli, typically dichotomously branched with its medulla surrounded by utricles. In addition to its thalli variations, the utricles which forms its thallus also has variety of forms, mainly based on their apical wall thickness and apex shapes. Similar to most seaweed species, ''Codium'' species also exhibit a wide range of morphological plasticity which has been a great challenge to its morphology-based taxonomy.

Distribution

In terms of its natural range, ''Codium'' has a latitudinal range that encompasses the tropical to temperate areas, however, this genus is not found in the frigid polar regions of the world.

Ireland

Two of these species are very rare in

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

. '' Codium adhaerens'' has been recorded from a few sites on the west coast and from

Tory Island Tory Island, or simply Tory, is an island 14.5 kilometres (7+3⁄4 nautical miles) off the north-west coast of County Donegal in the north-west of Ulster, the northern Provinces of Ireland, province in Ireland. It is officially known by its Iris ...

on the north coast in

County Donegal County Donegal ( ; ) is a Counties of Ireland, county of the Republic of Ireland. It is in the Provinces of Ireland, province of Ulster and is the northernmost county of Ireland. The county mostly borders Northern Ireland, sharing only a small b ...

. In 1837 it was found in Church Bay in

County Antrim County Antrim (named after the town of Antrim, County Antrim, Antrim, ) is one of the six counties of Northern Ireland, located within the historic Provinces of Ireland, province of Ulster. Adjoined to the north-east shore of Lough Neagh, the c ...

, but has not been found there since. * '' Codium adhaerens'' C.Agardh * '' Codium bursa'' (

Linnaeus Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...

) C.Agardh - has been found in Mulroy Bay in County Donegal in 1977 (specimen in the Ulster Museum) and 1988. There is an old record of it from "near

Belfast Belfast (, , , ; from ) is the capital city and principal port of Northern Ireland, standing on the banks of the River Lagan and connected to the open sea through Belfast Lough and the North Channel (Great Britain and Ireland), North Channel ...

" between 1793 and 1810. * ''

Codium fragile ''Codium fragile'', known commonly as green sea fingers, dead man's fingers, felty fingers,
Intertidal ...

'' ( Suringar) Hariot ** ''Codium fragile'' subsp. ''atlanticum'' ( A. Cotton) Silva * '' Codium tomentosum'' Stackhouse * '' Codium vermilara'' ( Olivi) Delle Chiaje There are other species of "doubtful validity":- '' Codium amphibium'' is included in William Henry Harvey's '' Phycologia Britannica'' Pl.xxxv. and noted as: "spreading in patches of great extent along the edge of the sea, over the surface of a turf-

bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and musk ...

which meets the shore at Roundstone Bay" (Ireland).

Worldwide

* '' Codium arabicum'' Kütz. -

Australia Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...

* '' Codium arenicola'' Chacana & P.C.Silva - Australia * '' Codium australasicum'' P.C.Silva - Australia * '' Codium bulbopilum'' Setch. - Australia * '' Codium bursa'' C.Agardh. - North Atlantic and Mediterranean * '' Codium capitulatum'' P.C.Silva & Womersley - Australia * '' Codium convolutum'' (Dellow) P.C.Silva -

New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla ...

* '' Codium cranwelliae'' Setch. - New Zealand * '' Codium cuneatum'' S. & G. -

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

(

United States The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 U.S. state, states and a federal capital district, Washington, D.C. The 48 ...

) * ''Codium decorticatum'' - Global * '' Codium duthiae'' Silva - Australia,

Tasmania Tasmania (; palawa kani: ''Lutruwita'') is an island States and territories of Australia, state of Australia. It is located to the south of the Mainland Australia, Australian mainland, and is separated from it by the Bass Strait. The sta ...

, and

South Africa South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...

* '' Codium dwarkense'' Børgesen - Australia * '' Codium edule -'' Indo-Pacific, including Hawaii * '' Codium extricatum'' Silva -

Cape Agulhas Cape Agulhas (; , "Cape of Needles") is a rocky headland in Western Cape, South Africa. It is the geographic southern tip of Africa and the beginning of the traditional dividing line between the Atlantic and Indian oceans according to the In ...

to southern

KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and ...

* ''

Codium fragile ''Codium fragile'', known commonly as green sea fingers, dead man's fingers, felty fingers,
Intertidal ...

'' ( Suringar) Hariot -

Nova Scotia Nova Scotia is a Provinces and territories of Canada, province of Canada, located on its east coast. It is one of the three Maritime Canada, Maritime provinces and Population of Canada by province and territory, most populous province in Atlan ...

(

Canada Canada is a country in North America. Its Provinces and territories of Canada, ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, making it the world's List of coun ...

) ** ''Codium fragile'' Sui song - ( Chinese) Food and food products from seaweeds

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

, American

Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the cont ...

from

Alaska Alaska ( ) is a non-contiguous U.S. state on the northwest extremity of North America. Part of the Western United States region, it is one of the two non-contiguous U.S. states, alongside Hawaii. Alaska is also considered to be the north ...

Cape Horn Cape Horn (, ) is the southernmost headland of the Tierra del Fuego archipelago of southern Chile, and is located on the small Hornos Island. Although not the most southerly point of South America (which is Águila Islet), Cape Horn marks the nor ...

and

British Isles The British Isles are an archipelago in the Atlantic Ocean, North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner Hebrides, Inner and Outer Hebr ...

Norway Norway, officially the Kingdom of Norway, is a Nordic countries, Nordic country located on the Scandinavian Peninsula in Northern Europe. The remote Arctic island of Jan Mayen and the archipelago of Svalbard also form part of the Kingdom of ...

Denmark Denmark is a Nordic countries, Nordic country in Northern Europe. It is the metropole and most populous constituent of the Kingdom of Denmark,, . also known as the Danish Realm, a constitutionally unitary state that includes the Autonomous a ...

, and

Netherlands , Terminology of the Low Countries, informally Holland, is a country in Northwestern Europe, with Caribbean Netherlands, overseas territories in the Caribbean. It is the largest of the four constituent countries of the Kingdom of the Nether ...

** ''Codium fragile'' subsp. ''capense'' Silva - South Africa * '' Codium galeatum'' J.Agardh - Australia * '' Codium geppiorum'' O.C.Schmidt - Australia and

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

South Africa * '' Codium harveyi'' P.C.Silva - Australia * '' Codium hubbsii'' Daws. - California (U.S.A.) * '' Codium intertextum'' Collins & Hervey * '' Codium isthmocladum''

Vickers Vickers was a British engineering company that existed from 1828 until 1999. It was formed in Sheffield as a steel foundry by Edward Vickers and his father-in-law, and soon became famous for casting church bells. The company went public in 18 ...

* '' Codium johnstonei'' Silva - California (U.S.A.) * '' Codium laminarioides'' Harv. - Australia * '' Codium lucasii'' Setchell - Australia, Tasmania * '' Codium mamillosum'' Harv. - Australia * '' Codium muelleri'' Kütz. - Australia * '' Codium perriniae'' A.H.S.Lucas - Australia * '' Codium pomoides'' J.Agardh - Australia * '' Codium setchellii'' Gardn. - California (U.S.A.) * '' Codium silvae'' Womersley - Australia * '' Codium spinescens'' P.C.Silva & Womersley - Australia * ''

Codium spongiosum ''Codium spongiosum'' is a species of seaweed in the family (biology), family Codiaceae. The light-green thallus has an applanate-to-pulvinate habit and is usually around across and thick. It has irregular lobes and moderately firm while aliv ...

'' Harv. - Australia * '' Codium strangulatum'' Chacana & P.C.Silva - Australia * '' Codium taylorii'' Silva - Australia * '' Codium repens'' ( P.Crouan & H.Crouan)

* '' Codium tenue'' ( Kütz.) Kütz. - Australia * '' Codium tomentosum'' Stackh. - Australia

Invasion of ''Codium'' spp.

Even though ''Codium'' species are well-distributed across the globe, certain species have managed to escape their natural range and invade other areas. In the case of ''C. fragile'' spp. ''tomentosoides'', commonly known as "oyster thief", the increasing marine traffic has made it possible for it to escape its natural locality (Japan) and spread to Europe and USA forcing devastating biodiversity and aquacultural losses.

Ecology

''Codium'' has been observed to inhabit both from the intertidal zone down to the subtidal area.

Life history

''Codium'', like most ulvophycean seaweeds, exhibit a diplontic life history wherein the dominant diploid (2N) thallus produces the male and female gametangia that will produce the haploid (N) gametes through meiosis. Moreover, ''Codium'' are also capable of fragmentation, which has led to its unwanted spread across the globe.

Exploitation, harvesting and cultivation

South Korea is the leading consumer and producer of farmed ''Codium'' (commonly known as ''cheonggak'') in the world; with about 4000 metric tons of fresh weight produced in 2017 and valued at 2 million US dollars. Farming and cultivation of ''Codium'' in South Korea is a thriving industry; their method first involves seeding a rope line with isolated pieces of utricles and medullary filaments and finally transferring it into the open sea for the grow-out cultivation.

Chemical composition/Natural products chemistry

A recent review on the bioactivity of the genus ''Codium'' has revealed that most of its polysaccharides, glycoproteins, galactans, anionic macromolecules, and other extracts/compounds have shown to have a variety of uses as immunostimulatory, anticoagulant, anticancer, anti-inflammatory, antibacterial, antifungal, and antiviral agent.

Utilization and Management

''Codium'' is used either fresh or dry and is typically cooked and seasoned with soy sauce and vinegar or mixed with kimchi.

References

{{Authority control Ulvophyceae genera Marine biota of Africa Marine biota of Europe Marine biota of North America Taxa named by John Stackhouse