Dictyota dichotoma | |
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Dictyota dichotoma at Capo Gallo, Palermo, Sicily | |
Scientific classification | |
Domain: | Eukaryota |
Clade: | Diaphoretickes |
Clade: | SAR |
Clade: | Stramenopiles |
Phylum: | Gyrista |
Subphylum: | Ochrophytina |
Class: | Phaeophyceae |
Order: | Dictyotales |
Family: | Dictyotaceae |
Genus: | Dictyota |
Species: | D. dichotoma |
Binomial name | |
Dictyota dichotoma | |
Synonyms [1] | |
List
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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.
The thallus of Dictyota dichotoma grows in tufts and is a yellowish-brown or greenish colour, with a faint bluish iridescence when underwater. It forms membranous, flattened, dichotomously-branching fronds up to 25 cm (10 in) long and 10 mm (0.4 in) wide. These have a reticulated (net-like) structure and no midrib. The tufts are semi-erect and have little or no stalk; they are anchored to the seabed by rhizoids, filamentous outgrowths that can absorb nutrients from their surroundings. The thallus branches are strap-like, the branches being equal in length and having rounded ends. Clusters of spores develop in round or oval sori under the surface of the thallus, finally bursting through. [2] [3]
Dictyota dichotoma has a wide range, being found in the western Atlantic Ocean and the eastern Atlantic Ocean from Scandinavia southwards to Mauritania, the Mediterranean Sea, the Black Sea, the Red Sea and the Indian Ocean. It grows on rock substrates in well-lit areas with little water movement, and sometimes on the fronds or holdfasts of other seaweeds. It is usually found at depths down to about 30 m (100 ft), but can exceptionally occur down to 80 m (260 ft). [2]
Dictyota dichotoma is dioecious, reproduction taking place in the spring and summer. The sporophytes and the gametophytes are similar in morphology, and the reproductive organs appear on the thallus as small, dark-coloured spots. Gamete release is linked to the phases of the moon. This alga is an annual, the thalli are abundant in summer but degenerate by the end of the year. [2]
As a brown alga, Dictyota dichotoma contains chlorophyll and other pigments for photosynthesis. [2] Research has shown that it contains many secondary metabolites, with at least seventeen diterpenes having been isolated from extracts of the thallus. [4] Also present were a range of other chemical compounds including alkaloids, steroids, tannins, flavonoids, phenols, coumarins, quinones and glycosides. Saponins were not present. [5] A methanolic extract was found to have antifungal activities against Candida albicans . [6]
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.
Ascoseira is a monotypic genus of seaweed in the brown algae. The single and type species, Ascoseira mirabilis Skottsberg, is a large parenchymatous macroalgae, and is endemic to the Antarctic Ocean. Ascoseira is assigned to its own order. The alga grows in subtidal waters at depths of from 3 to 15 meters.
Dictyotales is a large order in the brown algae. Members of this order generally prefer warmer waters than other brown algae. One genus in this order is calcareous, Padina, the only calcareous member of this phylum.
Polysiphonia is a genus of filamentous red algae with about 19 species on the coasts of the British Isles and about 200 species worldwide, including Crete in Greece, Antarctica and Greenland. Its members are known by a number of common names. It is in the order Ceramiales and family Rhodomelaceae.
Saccharina latissima is a brown alga, of the family Laminariaceae. It is known by the common names sugar kelp, sea belt, and Devil's apron, and is one of the species known to Japanese cuisine as kombu. It is found in the north Atlantic Ocean, Arctic Ocean and north Pacific Ocean. It is common along the coast of Northern Europe as far south as Galicia Spain, the coast of North America north of Massachusetts and central California, and the coast of Asia south to Korea and Japan.
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.
Laminaria hyperborea is a species of large brown alga, a kelp in the family Laminariaceae, also known by the common names of tangle and cuvie. It is found in the sublittoral zone of the northern Atlantic Ocean. A variety, Laminaria hyperborea f. cucullata is known from more wave sheltered areas in Scandinavia.
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.
Bonnemaisonia hamifera is a species of red alga in the family Bonnemaisoniaceae. Originally from the Pacific Ocean, it has been introduced into the northeastern Atlantic Ocean, where it is considered invasive on European coasts. It exists in two phases which, at one time, were thought to be different species; a medium-sized feathery form attached to other seaweeds, and a small tufted form known as Trailliella.
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.
Padina boergesenii, commonly known as the leafy rolled-blade alga, is a species of small brown alga found in the tropical and subtropical western Atlantic Ocean, the Mediterranean Sea, and the Pacific Ocean. This seaweed was named in honour of the Danish botanist and phycologist Frederik Børgesen.
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.
Zanardinia is a monotypic genus of seaweed in the brown algae. The only species, Zanardinia typus, commonly known as penny weed, is native to the northeastern Atlantic Ocean and the Mediterranean Sea.
Victor Wilhelm Lindauer (1888–1964) was a New Zealand phycologist, collector and teacher.
Dictyota implexa is a species of brown alga found in the temperate eastern Atlantic Ocean and the Mediterranean Sea.
Dictyota spiralis is a species of brown alga found in the temperate eastern Atlantic Ocean and the Mediterranean Sea.
Acinetospora crinita is a species of brown alga in the family Acinetosporaceae. It is found in the temperate northeastern Atlantic Ocean and the Mediterranean Sea.
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.
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