Morphological and molecular characteristics of Homoeostrichus formosana sp. nov. (Dictyotaceae, Phaeophyceae) from Taiwan

Abstract

BackgroundIn the marine brown macroalgae, the morphological characters are highly similar between two widely distributed genera, Homoeostrichus and Zonaria (Dictyotaceae), thereby resulting in the difficulty of exploring their hidden biodiversity. Owing to the help of the molecular tools, it is now easy for scientists to objectively describe a new species in nature. In this study, we make a description on the Homoeostrichus formosana sp. nov. from Taiwan, Indo-Pacific Ocean based on the morphological evidence and molecular data.ResultsOur morphological observations revealed that this species has marginal row of apical cells responsible for thallus growth and the thallus with four layers of cells except the marginal regions. The cortical cell lies upon each medullary cell in transverse section, and two cortical cells upon each medullary cell in longitudinal section. Tetrasporangium is developed from cortical cell with stalk cell and singly scattered over the thallus surface, and has no indusia and paraphyses. Molecularly, the phylogenetic trees based on SSU, psaA, psbA, and rbcL gene sequences supported that Homoeostrichus species are closely related to Exallosorus species and clearly separated from each others in addition to Zonaria species.ConclusionsHomoeostrichus formosana sp. nov. can now be clearly distinguished from E. harveyanus and Japanese H. flabellatus.Electronic supplementary materialThe online version of this article (doi:10.1186/1999-3110-54-13) contains supplementary material, which is available to authorized users.

Bioactive Chemical Constituents from the Brown Alga Homoeostrichus formosana

“…In continuation of our search for bioactive chemical constituents from marine alga [ 1 , 2 , 3 , 4 , 5 , 6 ], we found that a crude acetone extract of Homoeostrichus formosana (Dictyotaceae, Phaeophyceae) [ 7 ] displayed significant cytotoxic and anti-inflammatory properties. A novel chromene 2-(4',8'-dimethylnona-3' E ,7'-dienyl)-8-hydroxy-2,6-dimethyl-2 H -chromene ( 1 ), along with four known compounds methylfarnesylquinone ( 2 ) [ 8 ], isololiolide ( 3 ) [ 9 ], pheophytin a ( 4 ) [ 10 , 11 ], and β-carotene ( 5 ) [ 12 ] ( Chart 1 ) were identified for the first time using a bioassay-directed fractionation method.…”

Biological and therapeutic potential of the edible brown marine seaweed Padina australis and their pharmacological mechanisms

“…Padina is the only genus of brown algae which is calcified. Both surfaces of the thallus are lightly calcified, especially at the stipe (Wang et al, 2013).…”

“…The presence of Padina australis is distributed worldwide which it can be found in most Asia countries like Indonesia, Philippines, Thailand, Japan, Taiwan and others. Besides Asian countries, it can also be found in Ivory Coast, Cameroon, Gabon and Angola of West Africa, Hawaiian Islands of the Pacific Islands and also Queensland of Australia (Wang et al, 2013).…”

“…There are around 10,000 species of seaweeds found worldwide and they are all classified into three major classes which are red algae (Rhodophytes), brown algae (Phaeophytes) and green algae (Chlorophytes) (Mohsin et al, 2013). Seaweeds can be easily found all around the world, especially in Asian countries such as Japan, Philippines, Korea, Malaysia and Indonesia (Wang et al, 2013). Among the three major classes of seaweed, brown algae appear to be a popular food in Japan, Korea and China because seaweed is part of their main diet and they take it daily in most of their meals (Yan et al, 2007).…”