Production of Nile tilapia Oreochromis niloticus and freshwater prawn Macrobrachium rosenbergii stocked at different densities in polyculture systems in Brazil

The effect of stocking prawns Macrobrachium rosenbergii at increasing densities in ponds with Nile tilapia Oreochromis niloticus reared at low density was evaluated. Twelve 0.01-ha earthen ponds were stocked with 1 tilapia/m2 and 0, 2, 4, or 6 post-larvae prawn/m2. Three replicates were randomly assigned to each prawn density. Postlarval prawns were stocked a week prior to tilapia juveniles and both were harvested 175 d after the beginning of the experiment. Tilapia final average weight, survival, production, and food conversion rates did not differ significantly among treatments (P > 0.05); the averages were 531 g. 67%, 3,673 kg/ha, and 1.91, respectively. Prawn survival rates did not differ for the three stocking densities (mean 90%). However, final weight and production were significantly different (P < 0.05) as follows: 34.0, 23.0, and 14.7 g and 639, 909, and 818 kg/ha, respectively for 2, 4, and 6 prawns/m2 densities. Stocking densities up to 6 prawn/m2 did not affect tilapia production and required neither additional feeding nor significant changes in management. The polyculture system allowed an increase in total production with the same amount of supplied feed, thus improving the system sustainability.

Effects of nitrate concentration on larval development of the giant river prawn, Macrobrachium rosenbergii

The effect of nitrate concentration on giant river prawn, Macrobrachium rosenbergii, larvae was investigated. Survival rate, weight gain, and larval development were evaluated for different concentrations of nitrate in three experiments. The experiments were divided i n to two phases. In the first phase, larvae from stages I through VIII were analysed, while in the second phase larvae from stage VIII through post-larvae metamorphosis were analysed. Oxygen consumption was also determined for zoea I, II, and VIII exposed to 0, 700, and 1,000 mg/L of nitrate-N. No effect was observed for concentrations up to 180 mg/L NO3-N (experiments I and II), and nitrate levels as 1,000 mg/L NO3-N did not affect survival in the first phase of the third experiment. On the other hand, larval stage index (LSI) and weight gain decreased as nitrate-N concentration increased from 0 to 1,000 mg/L. In the second phase, survival and metamorphosis rate decreased as nitrate concentration increased, according to a linear model. The effect of nitrate levels on weight gain followed a curvilinear pattern. Larval respiration decreased in the water where nitrate was added, but only during stage II. The results demonstrated that nitrate presents extremely low toxicity for giant river prawn larvae, and data were related to the levels of nitrate that usually occur in larviculture systems also discussed. Therefore, nitrate is not a limiting factor for giant river prawn larviculture. © 2003 by The Haworth Press, Inc. All rights reserved.

Larval development of the giant river prawn Macrobrachium rosenbergii at different ammonia concentrations and pH values

The effect of ammonia and pH levels on giant river prawn Macrobrachium rosenbergii larvae were evaluated to provide science-based information on safe levels of ammonia and pH for larviculture. Survival rate, developmental stage, and larval weight gain were determined for larvae kept in water with total ammonia (NH4-N) concentrations of 0, 1, 2, 4, and 8 mg\L and pH 7, 8, and 9. The trials were conducted in two phases: phase 1, larvae from stages I through VIII and phase 2, larvae from stage VIII until metamorphose. Oxygen consumption was determined for larvae in stages I and VIII at total ammonia concentrations of 0, 4, and 8 mg/L and pH 8. Survival rate up to stage VIII varied from 86 to 98% and did not differ for total ammonia concentrations in pH 7 and 8 and for 0 mg/L NH4-N in pH 9. Survival rate was significantly lower (0-20%) for total ammonia concentrations from 1 to 8 mg/L (0.43-3.41 mg/L of unionized ammonia) in pH 9. Larval stage indexes (7.9-8.0 range) and weight gain (1.572-2.931 mg range) of larvae at the end of phase 1 of the experiment did not differ for the different ammonia concentration solutions, but were significantly lower in pH 9. In phase 2, no parameter differed among treatments for pH 7 and 8; however there was total mortality at pH 9 until 96h. Respiration rates diminished when larvae were exposed to total ammonia concentrations of 4 and 8 mg/L (0.28 and 0.55 mg/L of unionized ammonia), but development remained unaltered. Therefore, M. rosenbergii larvae tolerate high levels of total ammonia, while toxicity depends primarily on unionized ammonia concentrations. In addition, alkaline pH (9) acted directly on the larvae, curbing development and causing severe mortality. Larval tolerance to high ammonia and pH levels decreases for the last zoeal stages. © Copyright by the World Aquaculture Society 2005.

Shelf-life of tail meat of the giant river prawn, Macrobrachium rosenbergii, stored on ice

The objective of this study was to evaluate the shelf-life of peeled giant river prawn Macrobrachium rosenbergii stored directly in contact with ice (DCI), and without direct contact with ice (WCI). The prawns from DCI treatment showed an intense leaching of non-protein nitrogen (NPN) and total volatile bases nitrogen (TVB-N), thus suggesting that NPN or TVB-N should not be used as freshness indicators of peeled tails stored directly in contact with ice. Loss of flavor and a quick texture tactile decrease with time occurred in both treatments. The shelf-life of peeled tails prepared from M. rosenbergii was 7 days for DCI and 10 days WCI. © 2006 by The Haworth Press, Inc. All rights reserved.

Reproductive cycle, ovarian development, and vertebrate-type steroids profile in the freshwater prawn Macrobrachium rosenbergii

This study is intended to characterize the ovarian development and hemolymph vertebrate-type steroids concentration during the reproductive cycle of the freshwater prawn, Macrobrachium rosenbergii. A five-stage classification based on the external observation of the ovary's size and color as seen through the tegument was used. The results showed the existence of a direct correspondence between the ovarian stages and the gonadosomatic index, the oöcyte diameter, and the characteristics of ovarian histology. In each stage total bleeding of the prawns was conducted and the hemolymph concentrations of 17β-estradiol (E 2), testosterone (T) and 17α-hydroxyprogesterone (17-OHP; conjugated and unconjugated) were determined by solid-phase radioimmunoassay (RIA). High levels of unconjugated 17-OHP, relatively constant concentrations of unconjugated T, and null concentration of unconjugated E 2 were found throughout the five stages considered. Nonetheless, low levels of E 2 were determined in all stages, in conjugated (glucoronide) form. The highest levels were obtained in stage II and III (18.14 ± 14.52 pg/ml hemolymph) and progressively declined in the other stages (7.53 ± 6.76 pg/ml hemolymph). These results point out the possible involvement of vertebrate-type steroids in the endocrine regulation of the Macrobrachium rosenbergii's ovarian cycle. To our knowledge this is the first study concerning the vertebrate-like steroid levels throughout the ovarian cycle and is a step needed to characterize the hemolymph profile of these steroids in order to elucidate the possible role in the regulation of the reproductive crustacean cycle.

Crescimento de mudas de Schizolobium amazonicum (Huber ex Ducke) em substrato fertilizado com nitrogênio, fósforo e potássio

The nutritional management of seedlings in the nursery is one of the most important practices that influence seedling quality. The aim of this work was to evaluate the effect of nitrogen, phosphorus and potassium on the development of Schizolobium amazonicum seedlings grown in 250 cm containers with a commercial substrate in the North of Mato Grosso State, Brazil. The experimental design was completely randomized design with five treatments and five replications, each replication being represented by 24 seedlings. The treatments were: control (only commercial substrate); nitrogen fertilization (150 g m-3 N using ammonium sulfate + 1.0 kg of ammonium sulfate dissolved in 100 L of water and applied in coverage); phosphorus fertilization (300 g P2O 5 m-3 using simple superphosphate); potassium fertilization (100 g m-3 K2O using potassium chloride + 0.3 kg of potassium chloride dissolved in 100 L of water and applied in coverage) and; complete (a mixture of the three nutrients, 150, 300 and 100 g m-3 N, P2O5 and K2O, respectively + 1.0 kg of ammonium sulfate + 0.3 kg of potassium chloride). The commercial substrate was composted milled pine bark plus vermiculite. Evaluations of the seedlings were performed at 90 days after sowing. The complete treatment (NPK) gave the highest values for biometric and best plant indices, which express the quality. When analyzing nutrients in isolation; potassium had the lowest effect. Based on these results it can be recommended to fertilize Schizolobium amazonicum seedlings in nurseries with 150, 300 and 100 g m-3 of N, P2O5 and K2O, respectively, plus 1.0 kg of sulfate ammonium and 0.3 kg of potassium chloride applied in coverage.

Subcellular localization and kinetic characterization of a gill (Na +, K+)-ATPase from the giant freshwater prawn macrobrachium rosenbergii

The stimulation by Mg2+, Na+, K+, NH 4 +, and ATP of (Na+, K+)-ATPase activity in a gill microsomal fraction from the freshwater prawn Macrobrachium rosenbergii was examined. Immunofluorescence labeling revealed that the (Na +, K+)-ATPase α-subunit is distributed predominantly within the intralamellar septum, while Western blotting revealed a single α-subunit isoform of about 108 kDa M r. Under saturating Mg2+, Na+, and K+ concentrations, the enzyme hydrolyzed ATP, obeying cooperative kinetics with V M = 115.0 ± 2.3 U mg-1, K 0.5 = 0.10 ± 0.01 mmol L-1. Stimulation by Na+ (V M = 110.0 ± 3.3 U mg-1, K 0.5 = 1.30 ± 0.03 mmol L -1), Mg2+ (V M = 115.0 ± 4.6 U mg -1, K 0.5 = 0.96 ± 0.03 mmol L-1), NH4 + (V M = 141.0 ± 5.6 U mg -1, K 0.5 = 1.90 ± 0.04 mmol L-1), and K+ (V M = 120.0 ± 2.4 U mg-1, K M = 2.74 ± 0.08 mmol L-1) followed single saturation curves and, except for K+, exhibited site-site interaction kinetics. Ouabain inhibited ATPase activity by around 73 % with K I = 12.4 ± 1.3 mol L-1. Complementary inhibition studies suggest the presence of F0F1-, Na+-, or K +-ATPases, but not V(H+)- or Ca2+-ATPases, in the gill microsomal preparation. K+ and NH4 + synergistically stimulated enzyme activity (≈25 %), suggesting that these ions bind to different sites on the molecule. We propose a mechanism for the stimulation by both NH4 +, and K+ of the gill enzyme. © 2013 Springer Science+Business Media New York.

Efeito da intensificação na larvicultura do camarão-da-malásia Macrobrachium rosenbergii

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Caracterização do ciclo da vitelogênese do camarão de água doce Macrobrachium olfersi (Wiegmann, 1836) (Crustacea, Decapoda, Palaemonidae)

Pós-graduação em Ciências Biológicas (Biologia Celular e Molecular) - IBRC

Análise da variabilidade genética e do padrão de atividade esterásica no hepatopâncreas de camarões palemonídeos expostos a diferentes pesticidas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Desenvolvimento ontogenético de estruturas sensoriais em Macrobrachium rosenbergii (De Man 1879) (Crustacea, Palaemonidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Níveis de cálcio, fósforo, lipídeo e proteína na dieta inerte do camarão-da-malásia Macrobrachium rosenbergii, na fase larval

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The history of the introduction of the giant river prawn, Macrobrachium cf. rosenbergii (Decapoda, Palaemonidae), in Brazil: new insights from molecular data

The giant river prawn, Macrobrachium cf. rosenbergii, is one of the most cultivated freshwater prawns in the world and has been introduced into more than 40 countries. In some countries, this prawn is considered an invasive species that requires close monitoring. Recent changes in the taxonomy of this species (separation of M. rosenbergii and M. dacqueti) require a re-evaluation of introduced taxa. In this work, molecular analyses were used to determine which of these two species was introduced into Brazil and to establish the geographic origin of the introduced populations that have invaded Amazonian coastal waters. The species introduced into Brazil was M. dacqueti through two introduction events involving prawns originating from Vietnam and either Bangladesh or Thailand. These origins differ from historical reports of the introductions and underline the need to confirm the origin of other exotic populations around the world. The invading populations in Amazonia require monitoring not only because the biodiversity of this region may be affected by the introduction, but also because admixture of different native haplotypes can increase the genetic variability and the likelihood of persistence of the invading species in new habitats.

Feeding and larval growth of an exotic freshwater prawn Macrobrachium equidens (Decapoda: Palaemonidae), from Northeastern Pará, Amazon Region

No presente estudo foram realizados experimentos sobre alimentação, com a espécie de camarão de água doce Macrobrachium equidens. Foram, testados o tipo de alimento e a densidade de alimento adequada para o desenvolvimento das larvas. Para o experimento sobre o tipo de alimento, 8 tratamentos foram realizados: (I) inanição, (AL) microalgas, (RO) rotíferos, (NA) náuplios de Artemia, (RO + NA) rotíferos + Artemia, (AL + RO) microalgas + rotíferos, (AL + NA) microalgas + Artemia, (AL + RO + NA) microalgas + rotíferos + Artemia. Para o experimento sobre a densidade de alimento, foi utilizado o tipo de alimento que resultou em uma elevada taxa de sobrevivência no experimento anterior. Três tratamentos foram realizados: 4, 8 e 16 náuplios de Artemia/mL. A taxa de alimentação durante o desenvolvimento das larvas foi observada. A sobrevivência, o peso e o percentual de juvenis de cada experimento de alimentação foram determinados. Foi identificado que as larvas de M. equidens são carnívoras, no entanto, houve uma seletividade do tipo de alimento, pois as larvas concluíram o seu ciclo de zoea para a fase de juvenil somente quando os náuplios de Artemia foram disponibilizados. Verificouse também que as larvas se alimentam preferencialmente durante o período diurno, e são oportunistas em relação à densidade do alimento ofertado.

Fertilidade e fauna edáfica em solo sob reflorestamento com paricá (Schizolobium amazonicum Huber ex Ducke) no município de Aurora do Pará

Com este estudo objetivou-se avaliar a variação na fertilidade do solo e na fauna edáfica sob reflorestamento com paricá (Schizolobium amazonicum Heber ex. Ducke) em monocultivo ou em sistema agroflorestal quando comparados com floresta secundária em área experimental considerando a sazonalidade da precipitação no período de 2009 e 2010. A área experimental pertence a Fazenda Tramontina Belém S/A, localizada no nordeste paraense, no município de Aurora do Pará. Foram analisados quatro tratamentos submetidos a reflorestamento com: Curauá (Ananas comosus var. erectifolius L.B.Smith), Paricá (Shizolobium var. amazonicum Huber ex Ducke) sob a forma de monocultivos, Paricá + curauá (Ananas comosus var. erectifolius L.B.Smith; Shizolobium var. amazonicum Huber ex Ducke); Paricá + Mogno + Freijó + Curauá (Shizolobium var. amazonicum Huber ex Ducke; Switenia macrophylla, King; Cordia goeldiana Huber; Ananas comosus var. erectifolius L.B.Smith). As amostragens foram realizadas em dezembro de 2009, abril e julho de 2010, o que caracterizou o período sazonal de transição (estiagem para chuva intensa), chuva intensa e estiagem respectivamente, para avaliar a granulometria, densidade aparente, densidade da partícula, porosidade total e umidade atual, bases trocáveis, soma de bases, CTC, acidez, fósforo, teor de carbono orgânico, pH, em três profundidades diferentes (0 – 10 cm. 10 - 20 cm; 20 – 40 cm) e a ocorrência de macrofauna edáfica. Os resultados mostraram a ação dos períodos sazonais sobre a densidade aparente, densidade da partícula, porosidade total do solo. Fatores químicos como, por exemplo, carbono orgânico, cujos teores variaram entre 5,85 g/kg e 13,00 g/kg, com teores elevados no sistema de cultivo S2, sofreu alterações nos períodos sazonais chuva intensa e estiagem. Quanto a fauna edáfica, foram capturados 9.964 invertebrados pertencentes a 26 táxons diferentes. Os mais abundantes foram Hymenoptera- Formicidae (5.805), Coleoptera (1.454), Acari (862), Collembola (649), Diplopoda (307) e Isopoda (110). Dos 26 táxons identificados, aproximadamente 40% deles apresentaram apenas um representante nas três amostragens efetuadas ou em apenas uma delas. Os maiores valores para frequência relativa ocorreu no sistema de cultivo S2, S4 e S3, respectivamente. O maior valor para frequência absoluta ocorreu durante o período sazonal chuva intensa em S1. As áreas sob reflorestamento com monocultivo e sistema agroflorestal paricà + curauá mostraram melhores desempenhos na recuperação da fertilidade do solo e da fauna edáfica comprovando a eficácia do paricá em monocultivo ou em sistema agroflorestal na recuperação da fertilidade do solo e da fauna edáfica.