ABSTRACT
AbstractOstreopsis cf. ovata is a toxic epiphytic dinoflagellate widely distributed in warm waters that often co-occur with species of the genera Coolia, Fukuyoa, Gambierdiscus and Prorocentrum. We investigated a strain isolated from the coast of Ubatuba, Brazil (Southwest Atlantic Ocean) by light and epifluorescence microscopies; we also report molecular data based on the LSU rDNA and ITS markers. Cells were 35-65 µm in the dorso-ventral diameter and 20-40 µm wide. We obtained the sequence of a ~1 900 base pair region of the rRNA gene cistron. In the LSU rDNA phylogeny, the sequences under the names O. ovata and O. cf. ovata branched into three clades. The ITS marker showed greater resolving power and the sequences of O. ovata/O. cf. ovata split into five clades. Our ITS sequence branched in a clade with sequences of strains from the Mediterranean Sea, European Atlantic coasts, subtropical NE Atlantic, other sequences from Brazil at Rio de Janeiro, and a few sequences from Japan. The cell dimensions and thecal plate arrangement were under the variability range reported in other ocean regions. Our observations confirm O. cf. ovata as the most commonly recorded species of Ostreopsis in the SW Atlantic Ocean. Ostreopsis cf. ovata co-occurred with Coolia malayensis in Brazil and Asia, but it has been commonly reported from the Mediterranean Sea, where C. malayensis has not yet been recorded; while Coolia malayensis has been reported from the Caribbean Sea, but not O. ovata. With the current knowledge, it is difficult to understand the factors that determine the biogeography of the tropical epiphytic dinoflagellates. Rev. Biol. Trop. 65 (3): 1022-1032. Epub 2017 September 01.
ResumenOstreopsis cf. ovata es un dinoflagelado tóxico epifítico de amplia distribución en aguas cálidas, que a menudo coincide con especies de los géneros Coolia, Fukuyoa, Gambierdiscus y Prorocentrum. Investigamos una cepa aislada en la costa de Ubatuba, Brasil (Atlántico sudoccidental) mediante microscopía óptica y de epifluorescencia. Obtuvimos una secuencia de una región de unos 1 900 pares de bases del cistrón del gen del ARN ribosómico. Las células tenían 35-65 µm de diámetro dorso-ventral y 20-40 µm de ancho. En la filogenia del marcador LSU rADN, las secuencias con los nombres O. ovata and O. cf. ovata se sitúan en tres grupos. El marcador ITS mostraba un mayor poder resolutivo y las secuencias de O. ovata/O. cf. ovata se separan en cinco grupos. Nuestra secuencia ITS se sitúa en un grupo con secuencias de cepas procedentes del Mar Mediterráneo, costas europeas Atlánticas, Atlántico subtropical nororiental, otras secuencias procedentes de Río de Janeiro en Brasil, y algunas secuencias de Japón. Las dimensiones celulares y la disposición de las placas tecales se sitúan en el rango de variabilidad descrito en otras regiones oceánicas. Nuestras observaciones confirman a O. cf. ovata como la especie más comúnmente registrada de Ostreopsis en el Atlántico sudoccidental. Ostreopsis cf. ovata coindice con Coolia malayensis en Brasil y Asia. Ostreopsis cf. ovata ha sido comúnmente encontrada en el Mar Mediterráneo, donde C. malayensis aún no ha sido registrada. Coolia malayensis has sido registrada en el Mar Caribe, donde O. ovata aún no ha sido encontrada. Es difícil comprender los factores que determinan la biogeografía de los dinoflagelados epífitos tropicales, a partir del conocimiento actual.
ABSTRACT
ABSTRACT Coral reefs are one of the most vulnerable ecosystems to ocean warming and acidification, and it is important to determine the role of reef building species in this environment in order to obtain insight into their susceptibility to expected impacts of global changes. Aspects of the life history of a coral population, such as reproduction, growth and size-frequency can contribute to the production of models that are used to estimate impacts and potential recovery of the population, acting as a powerful tool for the conservation and management of those ecosystems. Here, we present the first evidence of Siderastrea stellata planulation, its early growth, population size-frequency distribution and growth rate of adult colonies in Rocas Atoll. Our results, together with the environmental protection policies and the absence of anthropogenic pressures, suggest that S. stellata population may have a good potential in the maintenance and recovery in the atoll. However, our results also indicate an impact on corals' recruitment, probably as a consequence of the positive temperature anomaly that occurred in 2010. Thus, despite the pristine status of Rocas Atoll, the preservation of its coral community seems to be threatened by current global changes, such as more frequent thermal stress events.
Subject(s)
Animals , Climate Change , Anthozoa/anatomy & histology , Anthozoa/growth & development , Coral Reefs , Time Factors , Atlantic Ocean , Brazil , Environmental Monitoring , Population Growth , Geographic MappingABSTRACT
Species of Cymatosiraceae (diatoms) studied from Santa Catarina and Rio Grande do Sul littorals: Campylosira cymbelliformis, Cymatosira belgica, Cymatosirella minutissima, Plagiogrammopsis minima and Plagiogrammopsis vanheurckii) are presented with a morphological description, dimension data, distribution in the studied area and are illustrated in light microscope, and scanning and transmission electron microscopes. Superficial sand samples from the swash zone and plankton were collected from over 30 marine sandy beaches. Cymatosirella minutissima and Plagiogrammopsis minima are new recordings in Brazil widening their distribution to South America, previously being restricted to Europe. Campylosira cymbelliformis was the species most often observed in plankton samples and Plagiogrammopsis minima in sediment samples. Cymatosira belgica and Plagiogrammopsis minima were recorded as abundant species in Mariscal, Quatro Ilhas and Zimbros reaching a relative frequency of 9.6%. The study adds new morphological data to some taxa as the presence of rimoportula on C. minutissima and one row of poroids on copulae of P. minima, these features being in agreement with Cymatosiraceae diagnosis.
As espécies de Cymatosiraceae (diatomácea) encontradas no litoral de Santa Catarina e Rio Grande do Sul: Cymatosira belgica, Campylosira cymbelliformis, Cymatosirella minutissima, Plagiogrammopsis minima e Plagiogrammopsis vanheurckii são apresentadas com descrições morfológicas acompanhadas de dados referentes a dimensões, distribuição na área de estudo e ilustrações em microscopia óptica, e eletrônica de varredura e de transmissão. As amostras da areia superficial foram coletadas na região de varrido das ondas e de plâncton em mais de 30 praias arenosas. Cymatosirella minutissima and Plagiogrammopsis minima são registros novos para o Brasil ampliando sua distribuição para a América do Sul antes restritas à Europe. Campylosira cymbelliformis foi a espécies mais frequentemente observada nas amostras de plâncton and Plagiogramma minima in the sediment samples. Cymatosira belgica e Plagiogrammopsis minima são registradas como espécies abundantes em Mariscal, Quatro Ilhas e Zimbros alcançando a freqüência relativa máxima de 9,6%. Este estudo adiciona novos dados morfológicos para alguns táxons com a presença de uma rimopórtula em C. minutissima e uma fileira de poróides nas cópulas de P. minima, estando estas características de acordo com a diagnose da Cymatosiraceae.
ABSTRACT
This study provides the first data on the population structure of swimming crab Callinectes ornatus Ordway, 1863 bycatch from coastal shrimp fishing in northern Rio de Janeiro State, Brazil (21º 30'-21º 50' S and 41º 05'-41º 07' W). Crabs were collected monthly from April 2006 to March 2007. A total of 5,611 specimens were analyzed, of which 3,951 were males and 1,660 ovigerous and non-ovigerous females. The overall sex ratio (2:1) differ significantly from the expected 1:1 proportion, being the mature males significantly predominant as bycatch in this fishery. The specimens' carapace width and weight varied from 27 to 126 mm (mean: 77.3 ± 12.3 mm) and 1.2 to 128.2 g (mean: 31.0 ± 14.4 g) for males, and 30 to 101 mm (mean: 63.4 ± 9.3 mm) and 1.7 to 66.0 g (mean: 16.4 ± 7.4 g) for ovigerous and non-ovigerous females. Seasonal comparisons did not reveal differences between the number of specimens captured in dry and rainy periods considering both sexes and maturity stages. The size at first maturity was 79 mm for males and 65 mm for females, and the carapace width-weight relationship indicated an alometric pattern for both sexes. The bycatch swimming crabs are locally used as bait, but the capture tendency for a specific sex/age-group can affect this population structure over time.
Este estudo fornece os primeiros dados sobre a estrutura populacional do siri Callinectes ornatus Ordway, 1863 capturado incidentalmente através da pesca camaroneira realizada no litoral norte do estado do Rio de Janeiro, Brasil (21º 30'-21º50' S e 41º 05'-41º 07' O). Os siris foram coletados mensalmente entre abril de 2006 a março de 2007. Um total de 5.611 espécimes foram analisados, dos quais 3.951 eram do sexo masculino e 1.660 fêmeas ovígeras e não ovígeras. A razão sexual (2:1) diferiu significativamente da proporção 1:1 esperada, sendo os machos maduros significativamente predominantes como captura incidental nesta pescaria. A largura da carapaça e o peso dos espécimes variaram de 27 a 126 mm (média: 77,3 ± 12,3 mm) e 1,2 a 128,2 g (média: 31,0 ± 14,4 g ) para machos, e 30 a 101 mm (média: 63,4 ± 9,3 mm ) e 1,7 a 66,0 g (média: 16,4 ± 7,4 g) para fêmeas ovígeras e não ovígeras. As comparações sazonais não revelaram diferenças entre o número de espécimes capturados nos períodos seco e chuvoso, considerando ambos os sexos e estágios de maturidade. O tamanho de primeira maturação foi de 79 mm para machos e 65 mm para as fêmeas, e a relação largura da carapaça-peso indicou padrão alométrico para ambos os sexos. Os siris capturados incidentalmente são utilizados localmente como isca, mas a tendência de captura sobre um grupo sexual/etário específico pode afetar a estrutura dessa população ao longo do tempo.