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In the present study, we observed seasonal variations in the density of decapod larvae as well as changes in density related to diurnal and tidal cycles. Among the decapod larvae collected, portunids and grapsids were the most abundant, especially during nocturnal ebb tides and near the surface. The same results were obtained in late winter (September) and late summer (March). These results demonstrated a flow of decapod larvae from Guanabara Bay to adjacent coastal waters. Luciferid (Lucifer faxoni) was the only group with high densities during flood tides and we suggest this is an evidence of L. faxoni larvae entering Guanabara Bay in late winter. Probably these changes in distribution of Lucifer faxoni among winter and summer were related to reproductive cycle in the bay. For the portunids, grapsids and ocypodids, a similar dispersion strategy was observed towards adjacent coastal waters in the surface during nocturnal ebb tides.
Larvas de crustáceos decápodes são organismos planctônicos comuns tanto em regiões costeiras rasas como em estuários. Nesse trabalho, foi acompanhada a variação da densidade das larvas de decápodes num ponto estratégico entre a porção interior da baía de Guanabara e a região costeira adjacente. A coleta de grandes quantidades de zoés de braquiúros, principalmente das famílias Portunidae e Grapsidae, na superfície durante as marés de vazante noturnas sugere uma tendência de exportação para a região costeira adjacente. A repetição desse padrão no inverno e no verão demonstrou que as respostas dos organismos às variações de luz e maré não foram alteradas de modo significativo entre as duas estações do ano, exceto para os luciferídeos. O fluxo observado para a única espécie de luciferídeo capturada (Lucifer faxoni) foi significativamente diferente entre os dois períodos do ano analisados. É provável que essas diferenças na distribuição de Lucifer faxoni seja relacionada ao ciclo reprodutivo da espécie. Foi observado um padrão de dispersão similar para as larvas zoé dos portunídeos, grapsídeos e ocypodídeos; transporte para a região costeira adjacente pela superfície durante as marés de vazante noturnas

We examined the spatial and temporal variations of coastal and oceanic epipelagic copepods (rainy–dry seasons of 2009) in a tropical area of the south-west Atlantic. Zooplankton samples were obtained at 48 stations along six transects perpendicular to the coast, in the subsurface water between the 25 and 3000 m isobaths, by horizontal hauls using a Multinet. Abundance (42–64,753 ind. m−3), biomass (0.08–113 mg C m−3) and daily copepod production (0.17–163.20 mg C m−3 d−1) showed longitudinal and latitudinal variability. The highest values were observed over the southern continental shelf during the dry season. Temoridae, Undinula vulgaris and Paracalanus quasimodo dominated the biomass and daily copepod production during the rainy season; while Calanoides carinatus, Calanopia americana, Clausocalanidae, Temoridae, Paracalanidae and Subeucalanidae dominated during the dry season. The copepod assemblages formed four different groups: rainy season–continental shelf (1), dry season–continental shelf (2), rainy season–continental slope (3) and dry season–continental slope (4). Temperature, salinity, chlorophyll-a and suspended particulate matter explained 45% of the productivity distribution of the dominant copepod species. This study is the first attempt to examine the biomass and daily copepod production in oceanic waters in the south-west Atlantic Ocean, and it showed that copepod biomass and production in a tropical region can be relatively high compared with other regions of the world's oceans.

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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.
Este trabalho descreve a estrutura da comunidade de copépodes em relação às condições hidrográficas da baía do Espírito Santo, no período de 1993 a 1997. As amostras do zooplâncton foram obtidas através de arrastos horizontais, quatro vezes ao ano, com uma rede de 200µm. A temperatura, a salinidade e o oxigênio dissolvido foram determinados nas amostras de água. A densidade média dos copépodes foi de 9.085 ind.m-3, com picos superiores a 15.000 ind.m-3, durante o verão e o outono de 1993 a 1995. Utilizou-se a PCA para relacionar as variáveis ambientais à distribuição dos copépodes. A comunidade dos copépodes, principalmente as altas densidades das espécies Acartia lilljeborgi, Oithona hebes, Oithona oculata, Paracalanus quasimodo, Parvocalanus crassirostris e Euterpina acutifrons foram relacionados à diminuição da diversidade. As variações espaço-temporais da temperatura e da salinidade influenciaram a abundância das espécies durante os cinco anos de coleta, com a alternância das espécies dominantes

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The copepod assemblage on the inner continental shelf adjacent to the coastal system of Camamu Bay (state of Bahia, Brazil) is described in relation to hydrographic conditions, during the wet and dry seasons of 2004. The zooplankton samples were obtained in vertical tows using a net with 200 µm mesh size. Temperature and salinity were measured, and the total density, frequency and percentage occurrence of the copepod taxa were determined for each sampling period. The highest densities were observed at the entrance of Camamu Bay (up to 7.473 ind.m-3), and the lowest on the adjacent inner continental shelf south of Camamu Bay (less than 500 ind.m-3). A total of 57 copepod taxa were identified. Paracalanus quasimodo Bowman, 1971, Subeucalanus pileatus (Giesbrecht, 1888), Clausocalanus furcatus (Brady, 1883), Corycaeus giesbrechti F. Dahl, 1894, Temora turbinata (Dana, 1849), Oithona similis Claus, 1866, Temora stylifera (Dana, 1849) and Nannocalanus minor (Claus, 1863) dominated numerically. The densities measured in both sampling seasons were significantly different: the means were 1.849 ± 1.922 ind.m-3 and 3.657 ± 3.170 ind.m-3 for the wet season and dry season, respectively. Depth and temporal variation in temperature and salinity influenced species abundance during the wet and dry seasons, with the dominant species alternating. Species richness and diversity increased on the inner shelf adjacent to the coastal system of Camamu Bay at the 30- and 50-m isobaths, suggesting that most species were oceanic in origin. The diversity was similar to other coastal systems of northeast Brazil