Halimeda tuna | |
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Halimeda tuna on the Sicilian coast | |
Scientific classification | |
Clade: | Viridiplantae |
Division: | Chlorophyta |
Class: | UTC clade |
Order: | Bryopsidales |
Family: | Halimedaceae |
Genus: | Halimeda |
Species: | H. tuna |
Binomial name | |
Halimeda tuna | |
Synonyms [1] | |
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Halimeda tuna is a species of calcareous green seaweed in the order Bryopsidales. It is found on reefs in the Atlantic Ocean, the Indo-Pacific region and the Mediterranean Sea. Halimeda tuna is the type species of the genus Halimeda and the type locality is the Mediterranean Sea. The specific name "tuna" comes from the Taíno language, meaning "cactus" and referring to the resemblance of the thallus to the growth form of an Opuntia cactus. [2]
Halimeda tuna is a calcareous green seaweed, attached to the seabed by a holdfast. [3] Each individual thallus (frond) consists of a single cell forming a tube with multiple cell nuclei. The cytoplasm is mobile and the nuclei, chloroplasts and other cell contents are free to move around inside the cell wall. [4] The tube has flattened, disc-like segments connected by flexible joints. The surface of these segments have swollen areas called utricles which together make a tabular "cellular pavement". Below and between these utricles, there are gaps and it is here that the fluid is saturated with calcium carbonate and crystalline needles of aragonite form. These stiffen the segments and make the seaweed unpalatable to fish. When the seaweed dies, this skeletal material breaks down into "sand". Members of this genus are likely to be one of the most important agents of calcification in the marine environment, considerably more productive in tropical seas than stony corals.[ citation needed ]
This species is found in the tropical and subtropical Indo-Pacific region, the Mediterranean Sea and the western Atlantic Ocean. It grows on rocky reefs from the shallow subtidal zone down to depths of about 70 m (230 ft). [5] In the Mediterranean Sea it occurs in two separate habitat types; shallow, warm lagoons and sheltered places in the central Mediterranean and deep water (18 m (60 ft)) rocky habitats in the northwest Mediterranean. [3] Similarly, in the Florida Keys, it is the dominant green alga in shallow back reef locations and in much deeper, less well lit, reef slope habitats. [6]
The thallus of this seaweed is often overgrown by epiphytes which are at their maximum abundance in summer. The segments are sometimes damaged by storms, but are replaced by new growth which occurs with rising temperatures and increasing amounts of irradiation and dissolved nutrients. [3] In the deepwater habitats in the Mediterranean, it is the dominant species and is often found in association with the encrusting red alga Mesophyllum lichenoides . In this habitat it tends to grow on vertical walls, under overhangs and in positions where it receives little sunlight. Its adaptation to dim light is assisted by its containing two accessory photosynthetic pigments, the green-absorbing carotenoids siphonein and siphonaxanthin, as well as chlorophyll a and chlorophyll b. [7] In Florida, reproductive events occurred simultaneously across the reef, with up to 5% of thalli developing gametangia. Asexual reproduction also occurred through fragmentation or the growth of vegetative stolons. [6]
This seaweed has been described as pleasant to eat with oil, vinegar, and salt. [8] [9]
Caulerpa is a genus of seaweeds in the family Caulerpaceae. They are unusual because they consist of only one cell with many nuclei, making them among the biggest single cells in the world.
Caulerpa racemosa is a species of edible green alga, a seaweed in the family Caulerpaceae. It is commonly known as sea grapes and is found in many areas of shallow sea around the world. Despite the name, it is not related to grapes. There are a number of different forms and varieties, and one that appeared in the Mediterranean Sea in 1990, which is giving cause for concern as an invasive species.
Halimeda is a genus of green macroalgae. The algal body (thallus) is composed of calcified green segments. Calcium carbonate is deposited in its tissues, making it inedible to most herbivores. However one species, Halimeda tuna, was described as pleasant to eat with oil, vinegar, and salt.
Codium is a genus of edible green macroalgae under the order Bryopsidales. The genus name is derived from a Greek word that pertains to the soft texture of its thallus. One of the foremost experts on Codium taxonomy was Paul Claude Silva at the University of California, Berkeley. 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.
Udotea is a genus of green algae in the family Udoteaceae.
Amphiroa is a genus of thalloid red algae under the family Corallinaceae.
Caulerpa prolifera is a species of green alga, a seaweed in the family Caulerpaceae. It is the type species of the genus Caulerpa, the type location being Alexandria, Egypt. It grows rapidly and forms a dense mass of vegetation on shallow sandy areas of the sea.
Jania is a genus of red macroalgae with hard, calcareous, branching skeletons in the family Corallinaceae.
Favia fragrum is a species of colonial stony coral in the family Mussidae. It is commonly known as the golfball coral and is found in tropical waters on either side of the Atlantic Ocean.
Stypopodium zonale is a species of thalloid brown alga in the family Dictyotaceae. It is found in shallow waters in the Caribbean Sea and in various other tropical and sub-tropical seas around the world.
Acetabularia caliculus, the umbrella alga, is a species of green alga found in shallow temperate and tropical seas. It usually grows on pebbles, shells or pieces of rock, and is often found in seagrass meadows, on mudflats and coral reefs, in estuaries and growing on the submerged roots of mangroves. Each individual thallus consists of a single cell with a long stipe and a terminal cup-shaped or flattened disc.
Lobophora variegata is a species of small thalloid brown alga which grows intertidally or in shallow water in tropical and warm temperate seas. It has three basic forms, being sometimes ruffled, sometimes reclining and sometimes encrusting, and each form is typically found in a different habitat. This seaweed occurs worldwide. It is the type species of the genus Lobophora, the type locality being the Antilles in the West Indies.
Dictyota is a genus of brown seaweed in the family Dictyotaceae. Species are predominantly found in tropical and subtropical seas, and are known to contain numerous chemicals (diterpenes) which have potential medicinal value. As at the end of 2017, some 237 different diterpenes had been identified from across the genus.
Dictyota bartayresiana, commonly known as a forded sea tumbleweed, is a species of brown alga found in the tropical western Indo-Pacific region and the Gulf of Mexico. It contains chemicals that are being researched for possible use as antimicrobials, as larvicides and as cytotoxins.
Hildenbrandia rubra is a marine species of thalloid red alga. It forms thin reddish crusts on rocks and pebbles in the intertidal zone and the shallow subtidal zone. It is a common species with a cosmopolitan distribution, and is able to tolerate a wide range of conditions.
Dictyota implexa is a species of brown alga found in the temperate eastern Atlantic Ocean and the Mediterranean Sea.
Dictyota dichotoma is a species of Brown algae found in the temperate western and eastern Atlantic Ocean, the Mediterranean Sea, the Black Sea, the Red Sea and the western Indian Ocean.
Halimeda opuntia, sometimes known as the watercress alga, is a species of calcareous green seaweed in the order Bryopsidales. It is native to reefs in the Indo-Pacific region, the Atlantic Ocean and the Mediterranean Sea.
Nà[m] Theophraftus (1. cap. hist. c. 12) scribit circa Opuntem herbulam effe quandam, quae ex foliis radicem mittat, ac cum suauitate mandi possit. Plinius verò ipsum sequutus (lib. 21.cap.17) circa Opuntem, inquit, Opuntia est herba, etiam homini-dulcis: mirúmque è folio ejus radicem fieri, ac sic eam nasci. Et certè credibile est hanc plantam recentem cum aceto, sale, & oleo, vel etiam sine sale, non minùs suauiter edi posse quàm Portulacae marinae & sìmilium folia.