Diversity and Phylogeny of Gymnodiniales (Dinophyceae) from the NW Mediterranean Sea Revealed by a Morphological and Molecular Approach

Albert Reñé,Jordi Camp,Esther Garcés

doi:10.1016/j.protis.2015.03.001

Albert Reñé, Jordi Camp + Show 1 more

Open Access

https://doi.org/10.1016/j.protis.2015.03.001

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Abstract

The diversity and phylogeny of dinoflagellates belonging to the Gymnodiniales were studied during a 3-year period at several coastal stations along the Catalan coast (NW Mediterranean) by combining analyses of their morphological features with rDNA sequencing. This approach resulted in the detection of 59 different morphospecies, 13 of which were observed for the first time in the Mediterranean Sea. Fifteen of the detected species were HAB producers; four represented novel detections on the Catalan coast and two in the Mediterranean Sea. Partial rDNA sequences were obtained for 50 different morphospecies, including novel LSU rDNA sequences for 27 species, highlighting the current scarcity of molecular information for this group of dinoflagellates. The combination of morphology and genetics allowed the first determinations of the phylogenetic position of several genera, i.e., Torodinium and many Gyrodinium and Warnowiacean species. The results also suggested that among the specimens belonging to the genera Gymnodinium, Apicoporus, and Cochlodinium were those representing as yet undescribed species. Furthermore, the phylogenetic data suggested taxonomic incongruences for some species, i.e., Gyrodinium undulans and Gymnodinium agaricoides. Although a species complex related to G. spirale was detected, the partial LSU rDNA sequences lacked sufficient resolution to discriminate between various other Gyrodinium morphospecies.

Highlights

The diversity of living marine dinoflagellates is estimated at 2,500 species (Gómez 2005; Sournia 1995)
2.1 Morphospecies detected During this study, 59 different species belonging to the Gymnodiniales were detected along the Catalan coast (Fig. 1)
Most organisms were identified by their characteristic morphological features, others were only unequivocally identified at the species level when their molecular phylogeny was determined, and some could not be confidently identified even though their rDNA sequences were obtained

Summary

Introduction

The diversity of living marine dinoflagellates is estimated at 2,500 species (Gómez 2005; Sournia 1995). Dinoflagellate taxonomy has been based on the morphological features of the different groups, with the major orders established (Fensome et al 1993; Taylor 1987). The interrelationships among the different lineages remain unresolved and many orders have proved to be polyphyletic (Moestrup and Daugbjerg 2007; Murray et al 2005; Saldarriaga et al 2004). The coupling of morphological features with molecular phylogenetic data has enabled analyses of the relationships between many genera and species (Handy et al 2009; Murray et al 2009; Taylor 2004). Most of the organisms that have been sequenced are cultivable photosynthetic species whereas there is little information for a large number of genera, such as those that are mixo- and heterotrophic. One method to avoid cell culture bias is single-cell PCR (Ruiz-Sebastián and O'Ryan 2001), which has been successfully and recurrently applied to dinoflagellates (Lynn and Pinheiro 2009)

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