Ostreopsis cf. ovata (Dinophyceae) Molecular Phylogeny, Morphology, and Detection of Ovatoxins in Strains and Field Samples from Brazil.

Silvia Nascimento,Fabiano Salgueiro,Luiz Mafra,Thais Cockell,Rodrigo Da Silva,Santiago Fraga,Guilherme Melo,Agatha De Morais,Adriana Menezes-Salgueiro,Gabriela De’Carli,Philipp Hess,Raquel Neves,Geovanna Borsato

doi:10.3390/toxins12020070

Abstract

Recurrent blooms of Ostreopsis cf. ovata have been reported in Brazil and the Mediterranean Sea with associated ecological, and in the latter case, health impacts. Molecular data based on the D1–D3 and D8–D10 regions of the LSU rDNA and ITS loci, and the morphology of O. cf. ovata isolates and field populations from locations along the Brazilian tropical and subtropical coastal regions and three oceanic islands are presented. Additional ITS sequences from three single cells from the tropical coast are provided. Toxin profiles and quantities of PLTX and their analogues; OVTXs; contained in cells from two clonal cultures and two field blooms from Rio de Janeiro were investigated. Morphology was examined using both light and epifluorescence microscopy. Morphometric analysis of different strains and field populations from diverse locations were compared. Molecular analysis showed that six of the seven sequences grouped at the large “Atlantic/Mediterranean/Pacific” sub-clade, while one sequence branched in a sister clade with sequences from Madeira Island and Greece. The toxin profile of strains and bloom field samples from Rio de Janeiro were dominated by OVTX-a and -b, with total cell quotas (31.3 and 39.3 pg cell−1) in the range of that previously reported for strains of O. cf. ovata.

Highlights

IntroductionSchmidt is a genus of benthic dinoflagellate that has been extensively studied in recent years due to the impacts caused by their recurrent toxic blooms to human health and marine ecosystems
O. cf. ovata cells with a small suture between plates 30 and 5” or just touching in a point were observed in cultures of strains UNR-05 and UNR-10, similar to cells depicted by Tibiriçá et al [30] in their Figure 4B,F
Blooms of O. cf. ovata are common at Armação dos Búzios and Arraial do Cabo in Rio de Janeiro, Brazil, and the presence of moderate ovatoxin concentrations in bloom field samples highlights the potential risk these toxic proliferations may represent to marine fauna and human health in the area

Summary

Introduction

Schmidt is a genus of benthic dinoflagellate that has been extensively studied in recent years due to the impacts caused by their recurrent toxic blooms to human health and marine ecosystems. The genus was first identified in tropical areas [1,2,3], and later studies showed the presence of Ostreopsis species in temperate regions [4]. Schmidt [1], O. lenticularis Y. Fukuyo [2], O. ovata Y. Fukuyo [2], O. heptagona D.R

Methods

Results

Discussion

Conclusion