Domain Eukaryota Class Florideophyceae Family Batrachospermaceae | Division Rhodophyta Order Batrachospermales Rank Genus | |
Similar Batrachospermales, Batrachospermum, Chantransia, Lemanea, Thorea | ||
Sirodotia Kylin (1912) is a freshwater red alga which was described by Kylin in 1912. The family Batrachospermaceae belongs to the order Batrachospermales and has six well known genera namely Batrachospermum Roth (1797), Kumanoa Entwisle et al. (2009), Sirodotia Kylin (1912), Nothocladus Skuja (1934), Tuomeya Harvey (1938) and Sheathia Salomaki and M.L.Vis in Salomaki et al., (2014).The morphology of the gametophyte of Batrachospermum, Sirodotia, Tuomeya, and Nothocladus are more are less similar to each other. Necchi and Entwisle (1990) proposed to delimit them from Generic level to section level of genus Batrachospermum Sheathia was the member of genus Batrachospermum and recently rose to generic level). Later phylogenetic studies revealed a distinctive genus level of the above with full support in bootstrap analysis (Vis et al., 1998) and Sirodotia has been raised to generic level.
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Taxonomic Characters
Attached, gelatinous gametophytic filaments, up to 17 cm long, with a beaded appearance varying from blue-green to yellow-green. Uniseriate central axis with large, cylindrical cells; 4–6 pericentral producing repeatedly branched fascicles of limited growth. In most species, rhizoid-like cortical filaments from lower side of pericentral cells. Each fascicle cell contains several, ribbon-like, parietal chloroplasts with no pyrenoid. Spermatangia budded off terminal fascicle cells, spherical, colorless, 4–7 µm diam. Little differentiated carpogonial branches with small cells. Carpogonia with broad trichogyne attached off-center to base, latter structure having a definite protrusion. Carposporophyte a branched filament creeping along main axis; carposporangia formed at branch apices. Carpospores germinate into chantransia (= pseudochantransia) stage, composed of branched, uniserate filaments. Meiosis and monosporangia not observed.
The genus Sirodotia has been recognized by the two important reproductive characters such as asymmetrical carpogonium in the gametophyte and indeterminate/ indistinct gonimoblast filament in the carposporophyte. Further recognition of species inside the genus is done by various distinct characters like morphology of the gametophyte, position of spermatangia, position of the carpogonial branch, gonimoblast filament arising from the side of from carpogonium, and the size of the carpogonium.
Species as per Algae Base
Sirodotia acuminata Skuja ex L.Flint S
Sirodotia ambigua Skuja ex T.J.Entwisle S
Sirodotia angolensis (West & G.S.West) Skuja C
Sirodotia ateleia Skuja S
Sirodotia ateleia var. australis Skuja ex T.J.Entwisle C
Sirodotia cirrhosa Skuja ex M.S.Balakrishnan & B.B.Chaugule C
Sirodotia delicatula Skuja C
Sirodotia fennica Skuja S
Sirodotia gardneri Skuja ex L.Flint C
Sirodotia goebelii Entwisle & Foard S
Sirodotia huillensis (Welwitsch ex West & G.S.West) Skuja C
Sirodotia iyengarii Balusami & Babu C
Sirodotia loefgrenii Skuja C
Sirodotia nigrescens (West & G.S.West) Skuja S
Sirodotia polygama Skuja ex L.H.Flint C
Sirodotia segawae S.Kumano C
Sirodotia sinica C.-C.Jao C
Sirodotia suecica Kylin C - type
Sirodotia suecica var. australis Skuja ex T.J.Entwisle C
Sirodotia tenuissima (Collins) Skuja ex L.H.Flint S
Sirodotia yutakae S.Kumano C
Note: 'C' indicates a name that is currently accepted taxonomically; 'S' a homotypic or heterotypic synonym
Distribution
Reported from tropical and temperate countries.
In India it is reported from Western Ghats and Eastern Ghats.