Morphological and phylogenetic analyses and sequencing of the partial LSU gene and internal transcribed spacer (ITS) regions of the rDNA gene were combined to study toxic strains of Alexandrium tamiyavanichi Balech collected from northeastern Brazilian coastal waters. All specimens were identified with A. tamiyavanichi mainly based on the shape of the anterior sulcal plate (S.a.), which was the most conservative character. Among the specimens studied, 8% did not conform to the morphological description of A. tamiyavanichi. The occurrence of transitory states between A. tamiyavanichi and Alexandrium cohorticula (Balech) Balech tended to confirm that both species are conspecific. The posterior sulcal plate (S.p.) was not a good taxonomic character as variability in its shape did not allow a clear assignment of specimens from the same clonal isolate to either morphologically defined species. Phylogenetic analyses confirmed the overall validity of morphological characters to delineate the evolutionary relationships among the clades of Alexandrium species analyzed here, indicating that A. tamiyavanchi is a valid species according to the morphological species concept. This analysis showed that the Brazilian strains form a monophyletic clade with Asiatic strains of A. tamiyavanichi, but with enough genetic distance to argue for long-term separation and isolation of locally established populations, extending the known biogeographic range of this species. On the higher phylogenetic level, our data also indicate that Alexandrium tropicale Balech forms part of the clade otherwise consisting of the morphologically defined freterculus group, and this A. tamiyavanichi ⁄ tropicale ⁄ fraterculus (Balech) Balech clade (including species from the formerly termed tropical Asian [TROP] clade) may be considered as a sister group of the Alexandrium tamarense species complex.

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The purpose of this study was to describe the composition and occurrence of potentially toxic and harmful species of thecate dinoflagellates in cultured shellfish, located at Armação do Itapocorói (AI) and Praia Alegre (PA) in the municipality of Penha, SC -Brazil. Water samples were collected and environmental parameters (salinity, water temperature and depth of Secchi disk) were determined weekly between April 2007 and April 2008 at two sites by a monitoring program maintained by the Laboratory for the Study of Harmful Algae, CTTMar, UNIVALI. The identification of the organisms was made through an Olympus microscope, model BX41 with up to 1000x. During the sampling period, we identified 21 species of thecate dinoflagellates potentially toxic and harmful in the genus Alexandrium, Ceratium, Dinophysis and Prorocentrum. The species P. obtusum (86%), D. acuminata (78.5%) and P. micans (72%) were very frequent throughout the period in the two sample points. The point with highest species richness was the AI, with 14 species, and the PA had the lowest richness with only two species. Most samples were considered rare relative to the abundance of thecate dinoflagellates compared to the presence of harmful microalgae, but during the month of September 2007, were considered abundant, during which there was a bloom of D. acuminata. The similarity between the two points throughout the sampling period reached a high coefficient (86%), and between the months examined, June 2007 showed the lowest similarity (10%) and July 2007 the greatest similarity recorded (91%). The composition and distribution of thecate dinoflagellates during the study showed that the existence of a dynamic community structure could be used as a tool to aid the monitoring of harmful algae mariculture activity in this region.

RESUMOFlorações de algas nocivas são eventos naturais que ocorrem em todos os oceanos e podem estar associadas com a presença de toxinas que afetam a saúde humana. Neste trabalho monitorou-se a ocorrência de toxinas causadoras de PSP, DSP e ASP em moluscos cultivados no Ribeirão da Ilha em Florianópolis entre fevereiro e setembro de 2006. Amostras para identificação do fitoplancton e variáveis ambientais também foram coletadas. A temperatura da água variou entre 17 e 28 ºC, a salinidade de 32 a 35 ‰ e a transparência da água de 0,6 a 3,1 metros, condições frequentemente observadas nesta área. A clorofila a variou de 1,1 a 5,9 mg m -3 caracterizando um ambiente mesotrofico. ) durante o período observado quando também não se observaou a presença de toxinas nos tecidos dos moluscos. PALAVRAS CHAVE: Monitoramento, Fitoplâncton, MariculturaAbstract: Implementation and evaluation of monitoring of harmful algae and phycotoxins in a molluscs farm in Florianópolis -SC. Phytoplankton blooms are natural event and when it is associated with a harmful effect, they are called harmful algal bloom. Globally, the main syndromes caused by phycotoxins are PSP, DSP and ASP. This paper describes the results of the monitoring of the occurrence of harmful algae and phycotoxins at Ribeirão da Ilha, a mussel culturing area at Baia Sul/Florianópolis, southern Brazil, behind February and September of 2006.The occurrence of phycotoxins in Perna perna tissue was accessed by mouse bioassay and high performance liquid chromatography, while the presence of harmful species by light microscopy, from net and integral tube samples. The water temperature ranged form 17 to 28 ºC, the salinity from 32 to 35 ‰ and the transparency from 0.6 to 3.1 meters. Chlorophyll a varied from 1.1 to 5.9 mg m , causing the observed negative results for toxin analysis and bioassays.

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Microscopy technique is traditionally employed for assessing phytoplankton taxonomy. However, chemical approaches, such as the identification of biomarker pigments, allow to elucidate microalgae groups more quickly, in addition to detecting these valuable compounds. This study aimed to identify the pigment profile of microalgae species and to determine the seasonal pigment fluctuation in a marine mussel farm. Water samples were collected periodically between the years of 2014 and 2015. Phytoplanktonic organisms were isolated and cultivated in f/2 liquid medium under controlled temperature and light cycle. Cell content extracts from each unialgal culture and water sample were analyzed by High Performance Liquid Chromatography (HPLC). Pigment profiles of 13 marine microalgae strains were identified (12 Diatoms and 1 Dinoflagellate). Chlorophyll a and fucoxanthin were most present in Diatoms, while peridinin was the major carotenoid in Prorocentrum micans. Bacillariophyceae had higher density in the summer and fall. Dinophyceae, Cryptophyceae, Euglenophyceae, Prasinophyceae, Dictyophyceae and Ebriidea, had an increase in density during winter and spring. Following the trend of phytoplankton groups, pigments such as fucoxanthin, zeaxanthin, diadinoxanthin, chlorophyll c3 and c2, were identified throughout the year. Prasinoxanthin, peridinin, dinoxanthin and antheraxanthin were identified in samples collected during winter and spring.

The main transport vector for exotic-invasive species around the world is ballast water in merchant ships, crossing natural biogeographic barriers. This is one of the main factors responsible for the reduction and homogenization of the global biota. As phytoplankton is the main group transported by these vessels, this study assesses the risk of bioinvasion in the port complex of Itajaí and Navegantes (southern Brazil), using a polyphasic approach, mixing classical taxonomy with molecular biology. Ballast water collections were carried out to analyze the traditional taxonomy and for clonal cultivation in the laboratory. A successful cultivation of 12 local strains and 10-ballast water was successful. In the latter case, some fresh water, contrary to the statement by the commanders of the exchange of water in the deep ocean (> 200 m). Molecular identification was performed by sequencing the complete ITS region, confirming the presence of Thalassiosira minuscula Krasske, 1941, harmful and of public health interest, previously not mentioned for the region. The species Pleurosigma W. Smith, 1852; Asterionellopsis glacialis (Castracane) Round, 1990; Trieres mobiliensis (Bailey) Ashworth and E.C. Theriot, 2013; Thalassiosira minima Gaarder, 1951; Skeletonema pseudocostatum Medlin, 1991; Pectinodesmus holtmannii E. Hegewald, C. Bock and Krienitz, 2013; Neodesmus Hindák, 1976; and Pseudopediastrum boryanum (Turpin) E. Hegewald, 2005, were identified. The results indicate the possibility of growth of the species found in the ballast environment, which may negatively alter the disposal environment. Keywords: exotic species, molecular identification, marine phytoplankton, port complex of Itajaí and Navegantes.