Transferring Gracilaria irregularis (Gracilariaceae, Rhodophyta) from Thailand to Gracilariopsis based on morphological and molecular analyses. Issue 1 (30th October 2013)

• Record Type: Journal Article
• Authors: Muangmai, Narongrit; Yamagishi, Yukimasa; Zuccarello, Giuseppe C.; Chirapart, Anong; Lewmanomont, Khanjanapaj
• Is Part Of: Phycological research. Volume 62:Issue 1(2014:Jan.)
• Page Start: 29
• Page End: 35
• Publication Date: 2013-10-30
• Subjects: Algae -- Japan -- Periodicals; Algae -- Periodicals; 579.8
• DOI: 10.1111/pre.12032
• Languages: English
• ISSNs: 1322-0829

Abstract

<abstract abstract-type="main"> <title>Summary</title> <p> <italic>Gracilaria irregularis</italic>, endemic to Thailand, was originally described from Ao Len, Trat peninsula, Thailand, and was characterized by a short, succulent thallus with irregular branching, <italic>verrucosa</italic>‐type spermatangia (a taxonomic criterion for <italic>Gracilaria</italic>) and the absence of nutritive filaments (a taxonomic criterion for <italic>Gracilariopsis</italic>). Due to the combination of characters diagnostic of both the genera <italic>Gracilaria</italic> and <italic>Gracilariopsis</italic>, the taxonomic status of this species is unclear. This present study reassesses the identity of <italic>G. irregularis</italic> based on morphological features and the large subunit of ribulose‐bisphosphate carboxylase/oxygenase gene sequences. Newly collected samples from the type locality and KU collection were investigated. Our morphological re‐examinations were relatively similar to the original type description, except that the male plants showed superficial <italic>chorda</italic>‐type spermatangia, an important characteristic recognized in <italic>Gracilariopsis</italic>. Molecular analysis placed <italic>G. irregularis</italic> in the <italic>Gracilariopsis</italic> clade, forming a well‐supported clade with <italic>Gracilariopsis bailiniae</italic>. Detailed morphology and molecular phylogenetic analyses clearly showed that <italic>G. irregularis</italic> is congruous with the generic concept of <italic>Gracilariopsis</italic>, and consequently the new combination of <italic>Gracilariopsis irregularis</italic> is proposed. We believe that in the original description a heterogeneous holotype was used. Our data also shows the problems that can occur when collections are made of multiple plants, of similar external morphology, to describe new species.</p> </abstract>