Distribuição da classe Thaliacea (Tunicata) em frente a costa do estado do Rio de Janeiro

Plankton was sampled at 63 station's during “Operação Rio de Janeiro I” in horizontal, vertical and oblique plankton hauls. The class Thaliacea was studied through the ohservation of 17.928 organims divided in 6 species: Salpa fusiformis, Thalia democratica, T. cicar, Doliolum nationalis Doliolum gegenbauri and Pyrosoma atlanticum. Various fases of life cycle of these species were observed and for the first time in brazilian coast water a young colonie of Pyrosoma atlanticum was appointed. The Thalia democratica and Thalia cicar separation was discussed. The resultd obtained through the horizontal distribution of the "Standing-stock" (org/100m3) of Thaliacea were compared wiht plankton biovolume and correlated with temperature and salinity data.CAPESForam realizadas 63 estações oceanográficas durante a “Operação Rio de Janeiro I” e coletadas amostras de plancton em arrastos horizontais, verticais e oblíquos. Estudou-se a classe Thaliacea, sendo identificadas 6 espécies num total de 17.928 indivíduos pertencentes às famílias: Salpidae (Salpa fusiformis, Thalia democratica, T. cicar), Doliolidae (Doliolum nationalis Doliolum gegenbauri) e Pyrosomatidae (Pyrosoma atlanticum) Foram observadas as diversas fases do ciclo de vida das espécies, sendo descrito pela primeira vez para nossas águas, a forma jovem da colônia de Pyrosoma atlanticum. E discutida ainda a separação de Thalia democratica e Thalia cicar. Os resultados obtidos da distribuição horizontal do "Standing-stock" (org/100m3) dos Thaliacea, são comparados com os parâmetros temperatura e salinidade

Larvas de Spongicolidae (Crustacea, Decapoda, Stenopodidea) do plâncton da região oceânica brasileira

Stenopodidea is comprised of the family Spongicolidae, which includes five genera (Spongicoloides, Spongiocaris, Spongicola, Paraspongicola, and Microprosthema), and the family Stenopodidae, with four genera (Engystenopus, Odontozona, Richardina, and Stenopus). In Brazil, Stenopodidea is represented by two species of the genus Stenopus and one of Microprosthema. For the present report, five larvae of two Spongicolidae collected during the cruise of the RV Thalassa between Rio Real (BA) and Cabo de São Tomé (RJ) were identified and described. Two species of Microprosthema were identified, one ascribed to M. semilaeve, the only member of Spongicolidae recorded until now in Brazil; and the other to an undescribed species of Microprosthema. The two species can be distinguished by the rostrum, which is as long as the carapace in M. semilaeve and shorter in Microprosthema sp.2; and by the presence of pleural spines on abdominal somites 1 to 3 in M. semilaeve and only on somites 2 and 3 in the second morphotype.Larvas de Spongicolidae (Crustacea, Decapoda, Stenopodidea) do plâncton da região oceânica brasileira. A infraordem Stenopodidea compreende as famílias Spongicolidae, que inclui cinco gêneros (Spongicoloides, Spongiocaris, Spongicola, Paraspongicola e Microprosthema), e Stenopodidae, com quatro gêneros (Engystenopus, Odontozona, Richardina e Stenopus). No Brasil, a infraordem Stenopodidea é representada por duas espécies do gênero Stenopus e uma de Microprosthema. No presente estudo, cinco exemplares de duas espécies de Spongicolidae coletadas durante o cruzeiro do RV Thalassa entre Rio Real (BA) e Cabo de São Tomé (RJ) foram identificados e descritos. Duas espécies de Microprosthema foram identificadas, uma atribuída a M. semilaeve, a única espécie de Spongicolidae registrada atualmente no Brasil, e outra atribuída a uma espécie ainda não descrita de Microprosthema. As larvas das duas espécies podem ser distinguidas pelo rostro, que é tão longo quanto a carapaça em M. semilaeve e mais curto na segunda espécie, e pela presença dos espinhos pleurais nos somitos abdominais 1-3 em M. semilaeve e somente nos somitos 2 e 3 no segundo morfotipo

Seasonal and spatial variability of appendicularian density and taxonomic composition in the Caravelas Estuary (Northeastern Brazil) and adjacent coastal area

This study aimed to identify and assess the seasonal and spatial variations of the appendicularians in the Caravelas River estuary and the adjacent coastal area. Samples were taken during 12 campaigns over five years (2001 and 2003-2006). Ten species were identified; the most abundant were Oikopleura dioica, Oikopleura rufescens, and Oikopleura longicauda. These species represented more than 95% of the total numbers of appendicularians. The remaining species were less frequent and occurred in low densities. The mean density of appendicularians found at the coastal stations (804 ind.m-3.) was higher than in the estuary (66 ind.m-3). However, the differences observed between the estuary and coastal stations were not significant (p=0.54). The samples taken during the dry season showed a higher mean density (587 ind.m-3) than in the rainy season (376 ind.m-3), and the differences between the seasons were statistically significant (p=0.004).<br>Esse trabalho teve como objetivo identificar e avaliar as variações espaciais e sazonais das apendiculárias no estuário do rio Caravelas e área costeira adjacente (17º35' - 18º22' S e 39º8' - 39º55'W). As coletas foram realizadas em 12 campanhas durante cinco anos (2001 e 2003 - 2006). Foram identificadas dez espécies, sendo que Oikopleura dioica, O. rufescens e O. longicauda foram as mais abundantes. Estas três espécies representaram mais de 95% do total de apendiculárias coletadas. As outras espécies foram menos freqüentes e ocorreram em baixas densidades. A densidade média de apendiculárias encontrada nas estações e costeiras (804 ind.m-3) foi maior que na de estuário (158 ind.m-3). As diferenças encontradas entre as estações de estuário e costeiras não foram significativas (p=0,73). As campanhas realizadas durante o período seco apresentaram densidade média (587 ind.m-3) maior que do período chuvoso (376 ind.m-3). As diferenças entre os períodos chuvoso e seco foram estatisticamente significativas (p>0,01)

Inter-annual variability of planktonic copepods in a tropical bay in southeastern Brazil

The aim of this work was to study the structure of the copepod community in relation to hydrographic conditions in Espírito Santo Bay, from 1993 to 1997. Zooplankton samples were obtained in the horizontal tows four times a year, using a 200 µm net. Temperature, salinity and dissolved oxygen were determined in the water samples. The overall mean density of the copepods was 9,085 ind.m-3 with the peaks exceeding 15,000 ind.m-3 in the summer and autumn during the first three years (1993 - 1995). The PCA analysis was used to relate the environmental conditions with the distribution of the copepods. The increases in the abundant species, namely Acartia lilljeborgi, Oithona hebes, Oithona oculata, Paracalanus quasimodo, Parvocalanus crassirostris and Euterpina acutifrons, were related to the decreases in the diversity. The spatial and temporal variations of the temperature and salinity influenced the abundance of the species during the five years of the sampling and the dominant species alternated in abundance