Dictyota binghamiae - Mermaid's Gloves

Family: Laminariaceae [Sahoo TAW] Dictyotaceae family.[Wiki][E-flora]

"Family Description: This order, composed of a single family, is best represented in tropical and subtropical regions of the world. Members have an alternation of isomorphic generations that are flattened and fan-shaped or repeatedly dichotomously divided. Growth is by means of a single conspicuous apical cell or a row of marginal initials. Some tropical members of the family are calcified. Reproduction is oogamous. Eggs and sperm are usually produced in sori on separate gametophytic plants. Sporophytic plants produce four or eight large, nonmotile spores per sporangium." [NPS-E-flora]

"This delicate seaweed is composed of erect, branched blades lacking midribs. The blades, which are up to 35 cm (14 in) tall, are rather light brown above but darken near the base. They are produced by creeping horizontal branches called stolons. The branches are mostly 1 to 1.5 cm (0.4 to 0.6 in) across; they are distally rounded and have minute teeth scattered along their edges" [NPS-E-flora]

"This species grows on rocks." [NPS-E-flora]

Habitat / Range

"Bathymetry: subtidal to 30 meters (98 feet) World Distribution: Langara Island (Queen Charlotte Islands), British Columbia, to Baja California, Mexico; Japan" [NPS-E-flora]

Dictyota Sp.

"Dictyota is a genus of seaweed in the Dictyotaceae family. Species are predominantly found in tropical and sub-tropical 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." [Wiki-2]

"Dictyota is found restricted to European Atlantic coasts and the Mediterranean Sea. It is found to be present from British Isles to various coasts in Europe (Portugal, Spain and France etc). D. dichotoma was most probably absent in the Indian Ocean and their presences in Pacific Ocean have also been questioned. Due to its morphological plasticity D. dichotoma geographical distribution has not been accurately determined. It has been found that distribution impacts life cycle strategies of, sexual vs. asexual cycle among Dictyota population (Tronholm et al. 2008)." [Sahoo TAW]

"Dictyota (Dictyotales) is the most commonly found brown alga in European Atlantic coasts and the Mediterranean Sea. The plant body of Dictyota is long, dichotomously branched, flattened, and brown in color. The apical portion of the frond is acute and has an entire margin. The short life cycle (less than 3 months) of Dictyota has three overlapping alternation of generations. The gametophyte forms sex organs in the male and female sori; female sori are deep brown, appearing as spots on both sides of the thallus, containing 25–50 oogonia arranged in rows with sterile oogonia at the margins. Each oogonium contains one egg cell, is fertilized externally, and develops to form the sporophyte. Haploid aplanospores or tetraspores are usually produced on mature sporophytes. As previously discussed, dictyotene, a pheromone, is secreted by the egg to attract sperm. Some members of the species secrete specific terpenoids such as pachydictyol to inhibit grazing by fish, amphipods, and sea urchins (Lee, 2008)." [Fleurence SHDP]

"Flagellar spines are a peculiarity of unknown function confined to male gametes of a few oogamous brown algae. The spermatozoids of Dictyota sp. are unique in possessing a longitudinal row of 12 very short spines on their single hairy flagella (these spermatozoids are basically biflagellate, but the second flagellum is reduced to its basal body only)." [Barsanti Algae]

Food Use

"Other brown algae, Dictyota, Sargassum and Turbinaria, are commonly cooked with coconut milk (Michanek, 1975)." [Chapman SU]

Other Use

Dictyota dichotoma; "When the leaves of this seaweed were burned, they appeared to repel or kill mosquitoes (Culex quinquefasciatus) according to the people of the state of Tamil Nadu, India (Thangam and Kathiresan 1992)." [UAPDS]


"Brown algae are well known for their production of polyphenolic phlorotannins. Currently there are over 1,200 compounds reported from brown algae (Phaeophyceae) with over a third coming from a single genus, Dictyota." [NPMA, Strengel]

"Rao et aL (I 977) recently tested a number of Indian algae for antibacterial activity and they found that extracts from Dictyota dichotoma, Gelidiella acerosa, Gracilaria corticata, Enteromorpha spp. and Padina gymnospora were effective against Bacillus megatherium and Staphylococcus aureus, but were not effective against gram -ve bacteria. The extracts were active against a number of bacteria and the activity exceeded that of well-known antibiotics such as penicillin." [Chapman SU]

"Gosch et al. (2012) reported a lipid content of 10–12% on dry weight basis for the macroalgae of genus Dictyota,... which is quite comparable to those reported for several microalgal species..." [Dominguez FIAFN]

"Among all the marine algae, the genera Dictyota, which consist of more than 40 species, are a prolific source of structurally novel diterpenoids. Many members of the genus Dictyota produce cyclic diterpenes as well as typical diterpenes with a 6-methyl-5-hepten-2-yl side chain A." [Seaweed Sustainability]

"The dolabellane-type diterpenes are also frequently encountered in seaweeds of the genus Dictyota. The dolabellane diterpenes, 290–292 (Barbosa et al., 2004; Barbosa et al., 2003), were isolated from the brown alga Dictyota pfaffii, and 290 exhibited significant antifeedant activity against the herbivorous sea urchin Lytechinus variegates as well as strong antiherpes simplex virus-1 activity in vitro (Barbosa et al., 2007). Four novel dolabellane diterpenoids, 293–296, were obtained from the brown alga Dictyota sp. (Viano et al., 2009). Compound 297 (Ayyad et al., 2011), isolated from the brown seaweed Dictyota dichotoma, also belongs to the dolabellane-type diterpene." [Seaweed Sustainability]

"Compound 360 is a diterpene epoxide from brown alga of the genus Dictyota and showed significant vasopressin receptor antagonist activity in vitro (Patil et al., 1993)." [Seaweed Sustainability]

"The major bioactive component of the extract obtained from the brown alga Dictyota dichotoma, dolabellane 3" [BCNS]

"(+)-Dictyol A and (+)-dictyol B from the brown alga Dictyota dichotoma are typical representatives [of prenylguaianes]." [Breitmaier Terpenes]

"Various derivatives of the prenylgermacrane dilophol, for example, occur in the algae Dilophus ligulatus, Dictyota dichotoma and Pachydictyon coriaceum." [Breitmaier Terpenes]

"The alga Dictyota acutiloba produces dictyolene, one of the rarely abundant prenyleudesmanes. Prenylcadinanes are more frequently found not only in marine organisms but also in higher plants and insects. They are usually referred to as bifloranes and, when containing a benzenoid ring, as serrulatanes." [Breitmaier Terpenes]

"Especially high levels of lipids have been reported in the brown algae Dictyota acutiloba and Dictyota sandvicensis (16.2% and 20.2%, respectively) [73]." [Marine Algae]

Volatile Oils


"the diethyl ether extract of Dictyota linearis was ineffective against microorganisms, whereas its ethanolic extract had an antimicrobial effect against gram-negative bacteria and Candida sp. This fact is related to the presence of bioactive metabolites, which are soluble in ethanol, but not in diethyl ether (Tüney et al., 2006)." [Dominguez FIAFN]

Dictyota menstrualis; "extracts of this species have anticoagulant (Albuquerque et al. 2004), anti-nociceptive and antiinflammatory (Albuquerque et al. 2013), and antiviral (Pereira et al. 2004) activity." [Pereira ESW]

"Heterofucan from Dictyota menstrualis was reported to have antinociceptive effect in the acetic acid-induced writhing tests while the hot plate test showed no effect in mice (Albuquerque et al., 2013)." [Fleurence SHDP]

"Dictyota atomaria collected from Okha, Gujarat, exhibited hypotensive activity" [BMNP]

Dictyota caribaea - Antiprotozoal Moo-Puc et al. (2008) [Fleurence SHDP]

Dictyota cervicornis - Antioxidant [Marine Algae]

"Seaweed extracts may also display antifungal and acetylcholinesterase (AChE) inhibitory activities. Dictyota humifusa extracts from South Africa showed the highest antifungal and AChE activities and inhibited Gramnegative Escherichia coli." [Marine Polysaccharides]

"Mild activity was found in the Brazilian brown seaweed Dictyota mertensii against Leishmania amazonensis promastigotes and intramacrophagic forms (Dos Santos Aliança et al., 2014)." [Fleurence SHDP]

Dictyota spiralis; "This species have nutritional and pharmaceutical applications (Pereira et al. 2012). The extracts of D. spiralis have antibacterial, antiviral and cytotoxic properties (Milchakova 2011, Pereira 2015a)." [Pereira ESW]

D. dichotoma is the source of sulfophenols and BASs antitumor and antibiotic activity; is also used in treatments for goiter and scrofula; a preventive medicine for heart disease and stroke (Milchakova 2011, Pereira 2015a).[Pereira ESW]

"Hydroxydictyodial from Dictyota spinulosa inhibits feeding in the omnivorous fish Tilapia mossambica.145 Three ichthyotoxic and phytotoxic diterpenes are isolated from Dilophus fasciola.146,147 Several diterpenes from Dictyota species exhibit significant cytotoxicity.147" [BMNP]

"The sulfated fucans from the seaweed species Dictyota mertensii, Lobophora variegata, Spatoglossum schroederi, and Fucus vesiculosus were reported to inhibit HIV reverse transcriptase (RT) by Queiroz et al. (2008). They have indicated that the galactofucan fraction from L. variegate, which is rich in galactose, fucose and glucose with a lower sulfate content, had a marked inhibitory effect on reverse transcriptase, with 94% inhibition for synthetic polynucleotides at a concentration of 1.0 µg/ml. On the other hand, fucan A from S. schroederi and D. mertensii, which contains mainly fucose with a lower sulfate level, showed a high inhibitory effect on RT at 1.0 mg/ml, with 99.03 and 99.3% inhibition, respectively. Meanwhile, fucan B from S. schroederi, which contains galactose, fucose and high sulfate level, showed a lower inhibitory activity (53.9%) at the same concentration." [HMA]

"In Figure 3b, the antibacterial activity of Dictyota spp. is shown. The aqueous extract showed slight activity against S. epidermidis and B. subtilis, whereas methanolic extract showed activity against B. subtilis only. Both the extracts showed activity against B. subtilis. Neither of the extracts were able to inhibit Ps. testosteroni, P. morganii, M. flavus or K. pneumoniae. In Figure 3c the antibacterial activity of P. wightiana is shown. The methanolic extract showed more activity than the aqueous extract. The greatest activity of the methanolic extract was against B. subtilis, followed by M. flavusand P. morganii. The other 2 bacteria were not affected. The aqueous extract showed negligible activity." [Hota BMP]

"A diterpenoid (dictyotetraene) has been isolated from Dictyota sp. from North Brittany Sea. Four diterpenoids (dischototetroal, dichotopentanol, dichotone and dichotodione) have been reported from Dictyota dichotoma (Hudson) Lamouroux (Dictyotaceae) growing in Pakistan. Several sterols, terpenes, polyols and certain metabolites have been isolated from these seaweeds. Some significant phytochemicals include dicdichane from Dictyota dichotoma and hauckiosterol from Dictyota hauckiana (Dictyotaceae) and Spatoglossum variabile Figari et De Notaris (Dictyoaceae); dictinol, dictindiol, dictintriol, amijiol and sargasterol from Dictyota indica Sonder (Dictyotaceae), padinolide from Colpomernia sinuosa (Mertens ex Roth) Derbes et Solier (Scytosiphonaceae) and Padina tetrastromatica Hauck (Dictyotaceae)." [HPEP]


"Numerous studies have shown that recovery from photoinhibition is delayed after exposure to additional UV-B irradiation (see the review of H€ader and Figueroa 1997). In contrast, Flores-Moya et al. (1999) demonstrated that in the marine macroalga Dictyota dichotoma a delay of recovery of photoinhibition is observed if the natural UV-B wavelength range is removed from the solar spectrum, in specimens collected from a high UV environment. This was later confirmed under simulated sunlight conditions with different aquatic plants in New Zealand (Hanelt et al. 2006) or in field studies with natural sun radiation (Hanelt and Roleda 2009)." [ECOStud - 219]

"Nultsch et al. (1987) showed that, depending on the duration and the fluence rate of the excessive irradiation, a decrease in both the photosynthetic efficiency and capacity in the brown alga Dictyota dichotoma was caused by photoinhibition. Recovery in a subsequent dim light period was very fast so that in this species the photosynthetic efficiency recovered from inhibition of 80% already within 1 h. Moreover, the action spectrum of photoinhibition revealed that the photoinhibitory radiation was absorbed by all photosynthetic pigments, and that photosystem II is the main site of the photoinhibitory process. According to the definition by Franklin et al. (2003) this species shows a high potential for photoprotection." [Hanelt SB]

"Seaweeds were observed to damage corals via abrasion, shading, or lipid-soluble allelopathic compounds transferred through direct contact. The effects of a lipidsoluble extract from various species of macroalgae (Ochtodes secundaramea, Dictyota bartayresiana, Lobophora variegata, Halimeda opuntia, and Amphiroa fragillisima in Panama) caused significant coral bleaching and suppression of photosynthetic efficiency in assays using both intact seaweeds and chemical extracts." [ECOStud - 219]


"Pseudoamphithoides feeds selectively on and builds domiciles from the chemically defended brown alga Dictyota (Hay et al. 1990a)" [ECOStud - 219]

"the assimilation efficiency in fishes was greatly reduced when feeding on a phlorotannin-rich diet (Boettcher and Targett 1993), and egg production in periwinkles was reduced by phlorotannins (Toth et al. 2005). Similarly, the terpenoid metabolites produced by the brown alga Dictyota significantly reduced growth, survival, and reproduction in some grazing amphipods (Cruz-Rivera and Hay 2003). These fitness effects can depend on metabolite concentration and on the specific herbivore species, as there is considerable variation in the effects of the same algal metabolite on even closely related herbivores. Conversely, some mesograzer populations can ultimately benefit from seaweed defenses by gaining protection from predators when living associated with a chemically defended host, even if this comes with reduced fitness as a trade-off (Hay et al. 1988, 1989a, b)." [ECOStud - 219]

"The only very clear case of nonphlorotannin brown algal secondary metabolites acting as antifoulants in nature that we are aware of is in Dictyota menstrualis (Order Dictyotales). Schmitt et al. (1995) reported that D. menstrualis was noticeably less fouled in nature than other macroalgae and that bryozoan larvae would not settle on D. menstrualis in laboratory bioassays even though they would contact its surface and would settle on several other species of brown and red macroalgae." [ECOStud - 219]

"Their results also revealed the aversion of herbivorous fish towards Dictyota spp., a brown macroalgae that uses chemical compounds as a grazing deterrent (Hay 1997; Paul et al. 1990)." [ECOStud - 219]

"Surface extracts of the brown alga Dictyota menstrualis have been shown to contain the diterpenoids pachydictyol A and dictyol E, which are also known to defend against herbivores, and algal surface extracts including these compounds inhibited the settlement of larvae of a fouling bryozoan when coated onto artificial surfaces (Schmitt et al. 1995)." [Henelt SB]

"Each of these herbivores exhibits strong feeding preferences for the brown seaweed Dictyota menstrualis (D. dichotoma in the references below), which is one of the least preferred foods of local omnivorous fishes; the diterpene alcohols produced by this alga deter feeding by the fishes but have no effect on, or at some concentrations stimulate, feeding by the mesograzers (Hay et al., 1987b, 1988d)."

"The larvicidal activity of various plant extracts such as Pedalium murex, Cleome icosandra, and Dictyota dichotoma has been found to be promising against Cx. quinquefasciatus and An. stephensi (Kalyanasundaram and Das 1985)." [Veer, HIRB]

Journals of Interest


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