Morphology and phylogeny of Prorocentrum porosum sp. nov. (Dinophyceae): A new benthic toxic dinoflagellate from the Atlantic and Pacific Oceans.

A new marine benthic toxic Prorocentrum species is described from the tropical/subtropical regions of the Atlantic (Colombian Caribbean Sea and Northeast Brazil) and Pacific (Southern Japan) oceans. Morphological cell structures were examined using light (LM) and scanning electron (SEM) microscopy. Prorocentrum porosum sp. nov. was characterized by 35.9-50.2 µm long and 25.4-45.7 µm deep cells, covered by broadly ovoid symmetric thecal plates. The surface of both thecal plates is smooth and covered by randomly scattered kidney-shaped pores (n = 102-149), rounder towards the center, absent in the central part, and surrounded by a conspicuous marginal ring of about 69-92 evenly spaced pores. Broad V-shaped periflagellar area exhibiting flagellar and accessory pores. The molecular phylogenetic position of P. porosum sp. nov. was inferred using partial LSU rRNA gene (rDNA) and rDNA ITS sequences. This new species branched with high support in a Prorocentrum clade including P. caipirignum, P. hoffmannianum and P. cf. lima (P. lima morphotype 5 sensuZhang et al., 2015). Pairwise comparison of ITS1 and ITS2 transcripts with these closest relatives revealed the presence of compensatory base changes (CBCs), with the exception of P. cf. lima (P. lima morphotype 5), which only showed in ITS2 a hemi-CBC (HCBC) and two base changes that possibly induce a structural modification. Toxin analyses performed in two Colombian and Brazilian strains in the present study detected the presence of low amounts of okadaic acid.

Diversity and Toxicity of the Genus Coolia Meunier in Brazil, and Detection of 44-Methyl Gambierone in Coolia tropicalis.

Coolia is a genus of marine benthic dinoflagellates which is widely distributed in tropical and temperate zones. Toxicity has been reported in selected Coolia species, although the identity of causative compounds is still controversial. In this study, we investigated the taxonomical and toxicological aspects of Coolia species from Brazil. Since light- and electron microscopy-based morphology was not enough to distinguish small-celled species, ITS and LSU D1-D3 phylogenetic analyses were used for species definition. Cultures of Coolia palmyrensis and Coolia santacroce were established from samples collected along the northeastern Brazilian coast, the first record of both species in South Atlantic waters. Cultures of Coolia malayensis and Coolia tropicalis were also established and exhibited acute in vivo toxicity to adults of Artemia salina, while C. palmyrensis and C. santacroce were non-toxic. The presence of 30 yessotoxin analogues, 7 metabolites of Coolia and 44 Gambierdiscus metabolites was screened in 14 strains of Coolia. 44-methyl gambierone (formerly referred to as MTX3) and a new isomer of this compound were detected only in C. tropicalis, using both low- and high-resolution LC-MS/MS. To our knowledge, this is the first report of gambierone analogues in dinoflagellates other than Gambierdiscus; the role of C. tropicalis in ciguatera poisoning thus deserves to be considered in further investigations.

Growth, chain formation, and toxin production by southern Brazilian Pseudo-nitzschia isolates under laboratory conditions.

Pseudo-nitzschia is a diatom genus capable of producing the neurotoxin domoic acid (DA), which has been related to mortalities of marine vertebrates, and the amnesic shellfish poisoning (ASP) in human consumers of contaminated bivalves. This study reports DA production among Pseudo-nitzschia strains isolated from shellfish farming areas in southern Brazil. Twenty-seven cultures of potentially toxigenic Pseudo-nitzschia species were established. Growth, stepped-chain formation, and DA production were evaluated in static, intermittently illuminated (12:12 photoperiod) batch cultures for 12 selected strains, and under continuous light and/or turbulence for a single Pseudo-nitzschia calliantha strain. Growth rate ranged from 0.16 to 0.39 day-1 among the 12 strains. Only P. calliantha and P. cf. multiseries yielded detectable levels of intracellular DA, reaching up to 0.054 fg cell-1 in late exponential and 0.15 pg cell-1 in early stationary phase, respectively. Continuous light impaired cell growth, and turbulence enhanced step-chain formation by threefold during exponential growth phase, but no DA production was detected under both conditions. The effect of turbulence on chain formation should be further evaluated in the field, once particle size is expected to affect the ingestion of toxic cells and thus toxin accumulation by certain DA vectors. The low cell toxicity revealed herein under laboratory conditions is in accordance with the low frequency of DA contamination episodes in south Brazilian waters. Nevertheless, monitoring of Pseudo-nitzschia abundance and DA presence in farming areas is continuously required to assure the quality of local shellfish products.

Diatomáceas (Bacillariophyta) marinhas e estuarinas do Paraná, Sul do Brasil: lista de espécies com ênfase em espécies nocivas / Marine and estuarine diatoms (Bacillariophyta) from Parana, southern Brazil: check-list with emphasis on harmful species

As listagens de espécies são importantes para conhecer a biodiversidade local. Se as espécies são nocivas e/ou exóticas, elas podem causar danos ambientais. O levantamento da biota aquática de regiões portuárias é valioso para informar quais as espécies de alto risco estão presentes na água (espécies exóticas e/ou nocivas). As espécies podem ser capturadas quando os navios estão atracados nos portos do Paraná durante a tomada de lastro. Então, estas espécies podem ser transferidas para o próximo porto onde será realizado o deslastro, iniciando-se o processo de invasão biológica. Neste artigo as diatomáceas marinhas e estuarinas do Paraná foram listadas com base em trabalhos publicados desde 1918 e nos resultados do projeto ALARME (Agua de Lastro: Análise de Risco, Plano de Manejo Ambiental e Monitoramento de Espécies Exóticas no Porto de Paranaguá, Paraná) no Complexo Estuarino de Paranaguá. Um total de 789 táxons específicos foram registrados, distribuídos em 167 gêneros. Destes, 575 táxons específicos, distribuídos em 152 gêneros, foram registrados para o Complexo Estuarino de Paranaguá. Algumas destas espécies são consideradas potencialmente nocivas, por sua produção de toxinas, como Amphora coffaeformis e Pseudo-nitzschia spp. Outras possuem efeitos nocivos por causarem anoxia devido ao excesso de biomassa que é decomposta por bactérias em períodos de florações. Além disso, pode ocorrer consumo excessivo de oxigênio pelas algas durante a respiração. Estas espécies são Asterionellopsis glacialis, Cerataulina pelagica, Coscinodiscus spp., Cylindrotheca closterium, Leptocylindrus spp. e Skeletonema costatum. Além destas, Chaetoceros spp. possuem setas que danificam as brânquias de peixes, causando massiva mortandade destes em algumas regiões. Algumas espécies encontradas nas amostras do projeto ALARME são novos registros para a costa do Paraná como Bellerochea horologicales, Biremis circumtexta, Gyrosigma macrum, Licmophora remulus,...

The species check-lists are important to know the local biodiversity. If they are harmful and/or exotic they can cause environmental damages. The portuary regions' aquatic biota survey is valuable to inform which are the high risk species in the water (exotic or harmful species). The species can be caught when the ships are anchored in Parana harbors during the ballast taken. After that, these species can be transferred to the next harbor where it will be discharged, so it starts the biological invasion. In this article the marine and estuarine diatoms of Parana have been listed based on some issues that have been published since 1918 and over the results of ALARME Project (Ballast Water: Risk analysis, Environmental Management Plan and Monitoring of Exotic Species in Paranagua Harbor, Parana) in the Estuarine Paranagua Complex. An amount of 789 specific taxa was recorded and distributed in 167 genera on Parana shore. Among the 789 a number of 575 specific taxa is distributed in 152 genera which were recorded in the Estuarine Paranagua Complex. Some of these species are considered potentially harmful for their toxins production i. e. Amphora coffaeformis and Pseudo-nitzschia spp. The other ones have harmful effects because of anoxia due to the excess of biomass decomposed by bacteriae during the blooming periods. Furthermore it can happens excessive oxygen consumption by algae during breathing. These species are Asterionellopsis glaciallis, Cerataulina pelagica, Coscinodiscus spp, Cylindrotheca closterium, Leptocylindrus spp and Skeletonema costatum. Furthermore, Chaetoceros spp, have setae that damage the fishes' gills causing mass mortalities in some regions. Some species found in samples of the ALARME project are new records for the Parana coast such as Bellerochea horologicales, Biremis circumtexta, Gyrosigma macrum, Licmophora remulus, Nitzschia behrei, Pseudo-nitzschia calliantha, P. multisseries and Thalassiosira subtilis var. máxima.