&amp;lt;i&amp;gt;Gracilariopsis lemaneiformis&amp;lt;/i&amp;gt; (Gracilariaceae, Rhodophyta) in the Mexican Coasts: A Case of Disjunct Distribution?

Kurt M Dreckmann,Martha Isabel Vilchis,Abel Sentíes,Oscar E Hernandez,María Luisa Nuñez-Resendiz

doi:10.4236/ajps.2020.112009

Abstract

Gracilariopsis lemaneiformis is a widely reported species of marine red algae, with records from around the world. Particularly in Mexico, it has been recorded along the coasts of the Gulf of Mexico and the Mexican Caribbean as well as the Tropical Mexican Pacific; so, its current distribution on the Mexican coasts is disjunct. From its molecular characterization with COI-5P and rbcL sequences of specimens collected at sites in Mexico where this species has been most frequently recorded, our aim was to re-evaluate the current distribution of Gp. lemaneiformis on the Mexican coasts and discuss the taxonomic implications. Phylogenetic analysis, supported by DNA species delimitation methods, genetic distances and morphological comparisons, showed that the current disjunct distribution of Gp. lemaniformis in Mexico is a consequence of taxonomic misidentifications. From our results, Gp. lemaneiformis is the only species of the genus with a distribution in the Tropical Mexican Pacific, whereas Gp. tenuifrons is the only species with a distribution in the Gulf of Mexico and the Mexican Caribbean. Also, we propose that Gp. cata-luziana is to be merged with Gp. tenuifrons, while Gp. costarisensis is to be merged with Gp. lemaneiformis.

Highlights

The COI-5P alignment consisted of 35 sequences of 675 base pairs long, the rbcL alignment consisted of 48 sequences with 1241 pb long
Phylogenetic analysis, supported by DNA species delimitation methods, genetic distances and morphological comparisons, showed that the current disjunct distribution of Gracilariopsis lemaneiformis in Mexico is a consequence of taxonomic misidentifications
Since the sequences of all the species discussed in the present study were not available with COI-5P, our discussion was based on the phylogenetic analysis with rbcL, using the phylogeny with COI-5P mainly to reinforce the molecular identification of our specimens

Summary

Introduction

Gracilariopsis E.Y. Dawson, with the type species Gp. sjoestedtii (Kylin) E.Y. Dawson, comprises 25 species currently accepted taxonomically [1]. Some species of this genus are commercially important because of the presence of polysaccharides, as agars, in their cell walls [3]

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