Rhipidosiphon lewmanomontiae sp. nov. (Bryopsidales, Chlorophyta), a calcified udoteacean alga from the central Indo-Pacific based on morphological and molecular investigations

Abstract

A new species of the green algal genus Rhipidosiphon, Rhipidosiphon lewmanomonnae sp. nov., is described after material from the Mu Ko Tha Lae Tai area (SE Thailand) and Okinawa (Japan) on the basis of morphology and molecular analyses. The new species grows epilithically, just under the low water mark and is occasionally exposed at spring low tide. It differs mainly from the other known species, the Indo-Pacific Rhipidosiphon javensis and the western Atlantic Rhipidosiphon floridensis, by the presence of a rhizoidal pseudocortex surrounding the monosiphonous stipe and the presence of intercalary siphon constrictions. A similar pseudocortex has been described in juvenile stages of some Udotea species, but in this genus, the stipe is polysiphonous and possesses a cortex of lateral appendages in the adult phase

RHIPILIA COPPEJANSII, A NEW CORAL REEF‐ASSOCIATED SPECIES FROM GUAM (BRYOPSIDALES, CHLOROPHYTA)1

“…Members of the genus Udotea have multiaxial stipes and fan‐ or funnel‐shaped blades (Littler and Littler 1990b). Rhipidosiphon is structurally similar, but has a much simpler uniaxial stipe and a single‐layered blade (Littler and Littler 1990a, Coppejans et al. 2011).…”

Large‐scale diversity reassessment, evolutionary history, and taxonomic revision of the green macroalgae family Udoteaceae (Bryopsidales, Chlorophyta)

“…Flabellate, calcified, monostromatic and uncorticated frond; Monosiphonous (becoming plurisiphonous near the frond in some species), uncorticated or pseudo-corticated, partially or not calcified; Stipe-frond junction continuous; Fine hyaline rhizoids at the base; Frond siphons cylindrical, dichotomously branched, arranged in parallel to sub-parallel, without anastomosis but cemented by calcification; Isomorphic dichotomies with asymmetrical constrictions above; Porous siphon sheath. Thailand (Coppejans et al, 2011), Bunaken (This study); Pacific Ocean: Okinawa (Sauvage et al, 2016), Papua New Guinea (This study), Vanuatu (This study), New Caledonia (Grande Terre, Surprises Is.) (This study), Fiji (Coppejans et al, 2011;This study), Tonga (This study).…”

“…Thailand (Coppejans et al, 2011), Bunaken (This study); Pacific Ocean: Okinawa (Sauvage et al, 2016), Papua New Guinea (This study), Vanuatu (This study), New Caledonia (Grande Terre, Surprises Is.) (This study), Fiji (Coppejans et al, 2011;This study), Tonga (This study). List of vouchers from this study: Fiji, Nagelelevu Lagoon, 2007: NOU087262;Fiji, Heemskercq reef, 2007: NOU087250;Fiji, Vanua Levu, 2007: NOU087256;Vanuatu, Bridgestock point, 2006.…”

“…Several authors have subsequently contributed to improve knowledge of species diversity (Farghaly, 1980;Meinesz, 1980;Littler & Littler, 1990a, 1990bVroom et al, 1998;Collado-Vides et al, 2009), and with the discovery of new species and the increase in morphological information, several authors have discussed the need to redefine genera (Agardh, 1887;Gepp & Gepp, 1911;Nizamuddin, 1963;Farghaly, 1980;Littler & Littler, 1990a;Dragastan et al, 1997). The few molecular-based studies conducted on Udoteaceae have highlighted conflicts between morphological and molecular information, revealing polyphyletic genera (i.e., Chlorodesmis, Penicillus, Poropsis, Rhipocephalus, Rhipidosipon, and Udotea) and unresolved phylogenetic relationships for most taxa (Kooistra, 2002;Lam & Zechman, 2006;Curtis et al, 2008;Verbruggen et al, 2009aVerbruggen et al, , 2009cCoppejans et al, 2011;Lagourgue et al, 2018;Wade & Sherwood, 2017;Cremen et al, 2019). When reassessing the classification of the order Bryopsidales using the chloroplast genome, and to avoid proliferation of new families with a parsimonious and practical purpose, Cremen et al (2019) proposed to abandon the Udoteaceae family in favor of tribe Udoteae, which the authors placed in family Halimedaceae Link, together with other families such as Rhipiliaceae Kützing and Pseudocodiaceae L. Hillis-Colinvaux, and the genus Halimeda.…”

Diversity and distribution of Udotea genus J.V. Lamouroux (Chlorophyta, Udoteaceae) in the Yucatan peninsula littoral, Mexico

“…Since the phylogeny does not support the current taxonomic division based on morphological and anatomical characters, these genera should be revised under the molecular and phylogenetic approach using sequences of 18S, ITS, rbcL, tufA, atpB, 16S genes. For example, the rbcL and tufA plastidial genes have proved to be good markers for the species delimitation of green algae Ulvophyceae (Fama et al 2002, Zucarello et al 2009, Verbruggen et al 2009b, Saunders & Kucera 2010, Coppejans et al 2011, Dijoux et al 2012, van der Loos et al 2017. It is imperative to generate more gene sequences of all morphological described Udotea species to resolve these taxonomic inconstancies.…”