Systematic revision of the widespread species Sarcodia ceylanica (Sarcodiaceae, Rhodophyta) in the Indo-Pacific Oceans, including S. suiae sp. nov.

The marine red algal genus Sarcodia possesses single to several flattened blades, composed of a central layer of medullary filaments, with some stellate cells remaining, flanked by two layers of subspherical to stellate cortical cells. Among the described species, S. ceylanica, previously regarded as a synonym of S. montagneana, is characterised by erect thalli composed of subdichotomously branched blades and has been widely reported from the Indian and western Pacific Oceans. Collections from various localities in the Indo-Pacific regions included many specimens fitting this broad concept of S. ceylanica but differed in blade morphology and were difficult to assign to any named species with confidence. In order to delineate the species boundaries within the suite of the specimens that morphologically resemble S. ceylanica and to clarify the phylogenetic significance of the morphological features used for separating species of Sarcodia, we used rbcL sequences to infer phylogenetic relationships among the available specimens. RbcL sequence analyses showed that the distribution of S. ceylanica is most likely restricted to its type locality Sri Lanka. The collections of S. 'ceylanica' analysed from Taiwan, Japan and Kenya were split into four clades and were genetically different from those collections of S. ceylanica from Sri Lanka. The molecular results also suggested that S. montagneana is distributed only in New Zealand. In addition, one new species, S. suiae S.-M. Lin & Rodriguez-Prieto, is described to accommodate specimens of S. 'ceylanica' from Taiwan. Records of S. 'ceylanica' and S. 'montagneana' from other locations in the Indo-Pacific regions should be regarded as doubtful until detailed morphological studies and molecular analyses of freshly collected specimens become available

Next-Generation Sequencing of an 88-Year-Old Specimen of the Poorly Known Species <i>Liagora japonica</i> (Nemaliales, Rhodophyta) Supports the Recognition of <i>Otohimella</i> gen. nov.

<div><p><i>Liagora japonica</i> is a red algal species distributed in temperate regions of Japan. This species has not been collected from its type locality on the Pacific coast of Japan since 1927 and seems to have become extinct in this area. For molecular characterization of <i>L</i>. <i>japonica</i>, we extracted DNA from the topotype material of <i>L</i>. <i>japonica</i> collected in 1927, analyzed seven genes using Illumina next-generation sequencing, and compared these data with sequences from modern samples of similar red algae collected from the Japan Sea coast of Japan. Both morphological and molecular data from modern samples and historical specimens (including the lectotype and topotype) suggest that the specimens from the Pacific and Japan Sea coasts of Japan should be treated as a single species, and that <i>L</i>. <i>japonica</i> is phylogenetically separated from the genus <i>Liagora</i>. Based on the phylogenetic results and examination of reproductive structures, we propose <i>Otohimella japonica</i> gen. et comb. nov., characterized morphologically by diffuse carposporophytes, undivided carposporangia, and involucral filaments initiated only from the cortical cell on the supporting cell.</p></div

Morphological examination of historical materials of <i>Liagora japonica</i> Yamada.

<p>A: Lectotype specimen. Scale bar = 2.0 cm. B: Herbarium specimen used in Chihara & Yoshizaki (1972) (TNS-AL 047542). Scale bar = 2.0 cm. C: A later post-fertilization stage showing developing gonimoblast cells (arrowheads) (Lectotype). Scale bar = 30 μm. D: Mature carposporophyte showing diffuse carposporophyte (TNS-AL 047542). Scale bar = 50 μm.</p

Morphological comparison among the description of Yamada [13] and Chihara and Yoshizaki [17], type specimens, and related samples with <i>Liagora japonica</i>.

<p>Morphological comparison among the description of Yamada [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0158944#pone.0158944.ref013" target="_blank">13</a>] and Chihara and Yoshizaki [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0158944#pone.0158944.ref017" target="_blank">17</a>], type specimens, and related samples with <i>Liagora japonica</i>.</p

Comparisons of features distinguishing among <i>Liagora japonica</i>, <i>Liagora</i> sensu stricto, and the genera with diffuse carposporophyte belonging to Liagoraceae.

<p>Comparisons of features distinguishing among <i>Liagora japonica</i>, <i>Liagora</i> sensu stricto, and the genera with diffuse carposporophyte belonging to Liagoraceae.</p

Morphological examination of modern samples of <i>Liagora japonica</i> Yamada.

<p>A: Habit (TNS-AL 195934). Scale bar = 1.0 cm. B: Herbarium specimen (TNS-AL 185628). Scale bar = 2.0 cm. C: Assimilatory filaments (TNS-AL 182118). Scale bar = 50 μm. D: Spermatangia (s) cut off from spermatangial parental cell (spc) (TNS-AL 190026). Scale bar = 10 μm. E: 4-celled carpogonial branch (TNS-AL 190026). cp = carpogonium. sc = supporting cell. Scale bar = 10 μm. F: 5-celled carpogonial branch (TNS-AL 182118). Scale bar = 30 μm. G: An early post-fertilization stage showing gonimoblast initial (gi), gonimoblast cells (arrowhead), and involucral filaments (arrows) (TNS-AL 182118). Scale bar = 20 μm. H: A later post-fertilization stage showing developing gonimoblast cells (arrowheads) and involucral filament (arrows) (TNS-AL 182118). Scale bar = 30 μm. I: Young carposporophyte showing the growth of the gonimoblast cells (arrowheads) and involucral filaments (arrows) (TNS-AL 182118). Note that the cells of carpogonial branch (cb) are not fused. Scale bar = 50 μm. J: Mature carposporophyte showing diffuse carposporophyte (TNS-AL 182118). Note that the cells of carpogonial branch remain distinct. Scale bar = 50 μm. K: Carposporangia (TNS-AL 190026). Note that carposporangia are not divided. Scale bar = 10 μm.</p