Effect of Water Exchange and Mechanical Aeration on Grow-out of the Amazon River Prawn in Ponds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Does water level affect benthic macro-invertebrates of a marginal lake in a tropical river-reservoir transition zone?

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Diversity of decapod crustaceans at the interface of unconsolidated seabed areas and rocky shores in tropical/subtropical Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Benthic foraminiferal distribution on the southeastern Brazilian shelf and upper slope

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Abundance and distribution of juvenile pink shrimps Farfantepenaeus spp. in a mangrove estuary and adjacent bay on the northern shore of São Paulo State, southeastern Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Population structure and reproductive period of whitebelly prawn Nematopalaemon schmitti (Holthuis 1950) (Decapoda: Caridea: Palaemonidae) on the southeastern coast of Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bathymetric distribution of the shrimp Rimapenaeus constrictus (Stimpson, 1874) (Decapoda, Penaeidae) in two locations off the southeastern Brazilian coast

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Influência do formato do aquário na sobrevivência e no desenvolvimento de larvas de matrinxã Brycon cephalus (Osteichthyes, Characidae)

Neste experimento, utilizaram-se cinco aquários cilíndricos com relevo no fundo (em forma de anel) e cinco retangulares com fundo liso para estudo da influência do formato do aquário na sobrevivência e no desenvolvimento de larvas de matrinxã Brycon cephalus. Observou-se melhor eficiência dos aquários retangulares, confirmada pela maior sobrevivência e biomassa. Os valores de temperatura, pH, condutividade e oxigênio dissolvido foram similares entre os tipos de aquários, sugerindo que esses parâmetros não influenciaram os resultados. O relevo no fundo dos aquários cilíndricos afetou negativamente o cultivo de larvas de matrinxã, pela criação de zonas com pequena capacidade da água em suspender partículas, o que resultou em acúmulo de dejetos, predadores, competidores e alimento. Aquários retangulares com fundo liso são mais adequados ao cultivo de larvas de matrinxã, por promover melhor circulação da água.

Composition and abundance of marine shrimps (Crustacea, Decapoda, Penaeidea) in Ubatuba bay, Ubatuba (SP), Brazil

This work aims to analyse the composition, abundance and distribution of the Penaeidea species which occur in the Ubatuba Bay (23 degrees 26'S and 45 degrees 02'W). The samples were monthly collected from October/1992 to September/1993. Each collect was composed of two parallel radials: the first (radial ''A'') was carried out in the mid region of the bay and the second one (radial ''B'') in the bay mouth. The trawls took one hour in a boat equipped with one otter-trawl (10 mm of mesh). The registered environmental factors were depth, bottom water temperature, granulometric composition and organic content of the sediment. After the trawls, the shrimp were separated from other marine organisms and counted. Eight species of shrimp were obtained: Xiphopenaeus kroyeri; Artemesia longinaris; Penaeus (L.) schmitti; P. (F.) brasiliensis; Trachypenaeus; constrictus; Sicyonia typica; S. dorsalis and Pleoticus muelleri. The most abundant species were X. kroyeri, A. longinaris, P. muelleri and T. constrictus. It was verified a very strong seasonality among the species. The X. kroyeri species occurred in both radials along the months but its abundance decreased from a November to March. Such fact is attributed to the temperature which reached a minimum value of 20 degrees C during this period. The species A. longinaris and P. muelleri were more frequent in the radial B which was caracterized by 14 +/- 1.3 m of depth, low organic content in the sediment (2.97%) and granulometric composition of medium sand. The distribution and abundance of these shrimps in the bay, beyond the hydrological features can be related to biotic factors as food availability, migration, inter and intra specific relations (competition, predation, etc.).

Discharge pulses of hydroelectric dams and their effects in the downstream limnological conditions: A case study in a large tropical river (SE Brazil)

To address daily fluctuations in electricity demands, the quantities of water passing through the turbines of hydropower plants can vary significantly (up to fourfold) during a 24-h cycle. This study evaluates the effects of hourly variations in water discharges on the limnological conditions observed in two below-dam river stretches. The study reservoirs, Capivara and Taquaruçu, are the 9th and 10th reservoirs in a cascade of dams in the Paranapanema River in south-east Brazil. The reservoirs exhibit different trophic conditions, water retention times, thermal regimes and spillway positions. Capivara Reservoir is deeper, meso-eutrophic, with a high water retention time and hypolimnetic discharges (32 m) varying between 500 and 1400 m3 s-1. In contrast, Taquaruçu Reservoir is relatively shallow, oligo-mesotrophic, and has a low retention time, with water discharges varying between 500 and 2000 m3 s-1. Its turbine water intake zone also is more superficial (7 m). For two periods of the year, winter and summer, profiles of limnological measurements were developed in the lacustrine (above-dam site) zones of the reservoirs, as well as in the downstream river stretches (below-dam site). In both cases, the sampling was carried out at 4-h intervals over a complete nictemeral cycle. The results demonstrated that the reservoir operating regime (water discharge variations) promoted significant differences in the conditions of the river below the dams, especially for water velocity, turbidity, and nutrient and suspended solids concentrations. The reservoir physical characteristics, including depth, thermal stratification and outlet structure, are also key factors influencing the limnology and water quality at the below-dam sampling sites. In the case of Capivara Reservoir, for example, the low dissolved oxygen concentration (<5.0 mg L-1) in its bottom water layer was transferred to the downstream river stretches during the summer. These study results demonstrated that it is important to continue such investigations as a means of verifying whether or not these high-amplitude/low-frequency variations could negatively affect the downstream river biota. © 2009 The Authors. Journal compilation © 2009 Blackwell Publishing Asia Pty Ltd.

Biologia populacional e reprodutiva do camarão sete-barbas na Baía de Santos, São Paulo

We investigated the sexual maturity, reproductive period and juvenile recruitment (both associated with salinity and temperature of bottom water) and sex-ratio of Xiphopenaeus kroyeri in Santos Bay, São Paulo. Monthly samples were obtained from June 2008 through May 2009 along four transects. Individuals were measured, sexed and the developmental stage of the reproductive system was macroscopically determined. The mean carapace length of females was larger than that of males. Females attained physiological maturity with 25.5 mm and males with 16.8 mm. The reproductive period was continuous with higher proportions of reproductive females in autumn. Although not significant, in February occurs a peak of reproductive females similar to March. An intermediate peak of these females occurs between August and October and it contributed to the recruitment in summer. The smallest amount of juveniles after the main peak of spawning (February, March and April) can be explained by migration or consequences of open access for fishery that occurs on June. The overall sex-ratio was approximately 1:1. However, when considering the spatial distribution, we observed a greater amount of reproductive females in shallow waters in the bay. The differential distribution between the sexes could be associated with appropriated areas to spawn. The current legal off-season occurs between March and May, and, according to our results of the frequency of reproductive females, we suggest the inclusion of February in the off-season.

Distribuição ecológica e dinâmica populacional do camarão sete-barbas Xiphopenaeus kroyeri(Heller, 1862) (Crustacea: Decapoda) no complexo Baia/Estuário de Santas e Sâo Vicente, SP

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Distribuição ecológica e dinâmica populacional do camarão barriga branca Nematopalaemon schmitti (Holthuis, 1950) (Caridea, Palaemonidae) na região de Macaé-RJ, Brasil

Pós-graduação em Ciências Biológicas (Zoologia) - IBB

Effect of environmental factors on the abundance of decapod crustaceans from soft bottoms off southeastern Brazil

Este estudo investigou a importância dos fatores ambientais sobre os padrões de abundância dos decápodos na costa sudeste brasileira. Amostragens foram feitas mensalmente de janeiro/1998 a dezembro/1999 em Ubatumirim e Mar Virado, região de Ubatuba, usando um barco de pesca camaroneiro equipado com redes doublerig. Foram selecionadas seis áreas adjacentes aos costões rochosos. Amostras de água de fundo foram coletadas usando garrafa de Nansen, para mensurar a temperatura e salinidade. Amostras de sedimento foram obtidas utilizando pegador de Van Veen, para determinação da textura e conteúdo de matéria orgânica. A associação dos fatores ambientais com a abundância das espécies foi verificada através da Análise de Correspondência Canônica (α = 0,05). Quarenta e uma espécies de Decapoda foram utilizadas na análise multivariada. A análise indicou que a textura do sedimento (phi) e a temperatura foram os fatores mais fortemente correlacionados (p < 0,05) com a abundância espacial e temporal das espécies. Considerando a região de estudo como zona de transição faunística, incluindo espécies de origem tropical e subantártica, as espécies responderam diferentemente aos fatores ambientais, principalmente à temperatura. Possivelmente os decápodos ajustem sua distribuição de acordo com suas limitações fisiológicas intrínsecas, como resultado dos recursos disponíveis.

Reproductive biology of Hepatus pudibundus (Crustacea: Brachyura), the most abundant crab on the southeastern Brazilian coast

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)