Effects of ambient nitrite on amazon river prawn, macrobrachium amazonicum, larvae

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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)

Sex and reproductive stage differences in the growth, metabolism, feed, fecal production, excretion and energy budget of the Amazon River prawn (Macrobrachium amazonicum)

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

Integrated multi-trophic culture of Nile tilapia (Oreochromis niloticus) and Amazon river prawn (Macrobrachium amazonicum) in brackish water

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

The ultrastructural evaluation of digestive cells in the hepatopancreas of the Amazon River prawn, Macrobrachium amazonicum

The Amazon River prawn Macrobrachium amazonicum is endemic to tropical South America and is being intensively exploited by artisanal fisheries in Brazil. Limited information is available about the nutritional requirements of M. amazonicum, although the production of this species is now technically feasible. The digestive process in this species is still unclear and investigation into the digestive cells of its hepatopancreatic epithelium is required. Thus, the hepatopancreas from 15 specimens were fixed in Karnovsky Solution and processed for Transmission Electron Microscopy. Our results indicate that E cells are located at the distal portion of the hepatopancreatic tubule and are involved in mitotic activity. The cylindrical R cells are sparse and are only found in the proximal portion of the hepatopancreatic tubule. According to its ultrastructural characteristics, this cell is involved in pinocytosis. M cells are generally found near the R cells. The F cells are scattered throughout the length of the hepatopancreatic tubules, and B cells are observed mainly in the proximal and middle regions. F cells and B cells are likely related to, respectively, the synthesis of enzymes and the intracelular digestion. R- and M cells are probably related to material storage. Thus, these findings provide basic information on the cell types that perform protein digestion in M. amazonicum, and will be useful in further nutritional research. The identification and characterization of digestive cells is an important step towards understanding the digestive mechanisms.

Morphotypes in male Amazon River Prawns, Macrobrachium amazonicum

The occurrence of morphotypes in Macrobrachium amazonicum males was investigated. Prawns aged 4 to 24 months were taken from 10 aquaculture earthen ponds. Color and spination of right second cheliped were analyzed under a stereomicroscope. Post-orbital and carapace length were measured as well as the length of the cheliped and all limb joints on the right second pereiopods. Four distinct morphotypes were identified: Translucent Claw (TC), Cinnamon Claw (CC), Green Claw 1 (GC1) and Green Claw 2 (GC2). They differed in cheliped morphology and some morphometric relationships. Chelipeds were translucent in TC prawns while in CC they were generally cinnamon-color. Both showed a few spines and some low prominences similar to very small tubercles. GC1 and GC2 showed long moss green chelipeds provided with long and robust spines. However, in GC2, cheliped length was always greater than post-orbital length and the angles of spines on the carpus and propodus were more open, ranging from 51°to 92°, while, in GC1 it varies from 34°to 65°. Cheliped length, the cheliped length/post-orbital length ratio and the spine angle were significantly different among the four morphotypes. A description for the identification of each group is provided and the development of M. amazonicum males is discussed. Each morphotype may play a different role in the population and in the environment in which it lives. Therefore, the identification of morphotypes is advisable for future researches on the biology and culture of M. amazonicum. © 2004 Elsevier B.V. All rights reserved.

Kinetic Analysis of Gill (Na+,K+)-ATPase Activity in Selected Ontogenetic Stages of the Amazon River Shrimp, (Decapoda, Palaemonidae): Interactions at ATP- and Cation-Binding Sites

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

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

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

Effect of nitrite on larval development of giant river prawn Macrobrachium rosenbergii

The effects of ambient nitrite concentrations on larval development of giant river prawn Macrobrachium rosenbergii were evaluated. The trials were conducted in two phases: phase 1, larvae from stages I through VIII and phase 2, larvae from stage VIII until post-larvae. In both phases larvae were kept in water with nitrite (NO2-N) concentrations of 0, 2, 4, 8 and 16 mg/L. Oxygen consumption was analyzed for larvae in stage II at nitrite concentrations of 0, 4, and 8 mg/L. Survival, weight gain, larval stage index and metamorphosis rate decreased linearly with increasing ambient nitrite concentration. However, there was no significant difference between larvae subjected to 0 and 2 mg/L NO2-N. In phase 1, there was total mortality at 16 mg/L NO2-N, while in phase 2 larval development stopped at stage X in this treatment. The oxygen consumption in stage II increased significantly at NO2-N concentration from 0 to 4 mg/L, but there was no difference between 4 and 8 mg/L NO2-N. In conclusion, increasing ambient nitrite up to 16 mg/L NO2-N delays larval development, reduces larval growth rate and causes mortality, whereas no significant effect occurs for levels below 2 mg/L NO2-N. However, the establishment of a general safe level of nitrite to M rosenbergii hatchery may be difficult due to the great variability in larvae individual sensitivity. (c) 2006 Elsevier B.V. All rights reserved.

Sensory aspects of liquid smoking of giant river prawn: comparison with traditional smoking

P>The purpose of this paper is to investigate the impact of liquid smoke on the sensory characteristics of giant river prawn (Macrobrachium rosenbergii). The sensorial profile was plotted using quantitative descriptive analysis and assessment of the acceptability of samples of beheaded and peeled and only beheaded freshwater prawns smoked using the traditional method or liquid smoke (LS). The prawns subjected to LS were characterised by their aroma, artificial flavour and bitter flavour. The beheaded, peeled prawns were found to be more acceptable, confirming that the presence of the shell is a limiting factor in the acceptability of smoked prawns.

Reproductive indices in natural nests of giant Amazon river turtles Podocnemis expansa (Schweigger, 1812) (Testudines, Podocnemididae) in the Environmental Protection Area Meanders of the Araguaia river

Realizou-se a contagem dos ovos não eclodidos, dos filhotes vivos e mortos de Podocnemis expansa oriundos de 327 ninhos naturais, localizados nas praias da Área de Proteção Ambiental (APA) - Meandros do Rio Araguaia, onde se determinou a porcentagem de eclosão dos ovos (94,63%); não eclosão (5,37%); sobrevivência (94,24%) e mortalidade dos filhotes (5,76%), e a média de filhotes mortos durante os 15 dias no berçário (0,97%). A média do total de filhotes por ninho foi determinada pela soma do número de filhotes vivos e mortos divididos pelo total de ninhos, enquanto que a média do total de ovos por ninho foi determinada pela soma do número de filhotes vivos, mortos e ovos não eclodidos divididos pelo total de ninhos. Com isso, obtiveram-se os valores médios do número de filhotes vivos (88,98 ± 23,94); mortos (0,37 ± 0,93); ovos não eclodidos (5,07 ± 9,57), e total de ovos (94,42 ± 21,30). A eficiência reprodutiva da população selvagem de P. expansa pode ser afetada por muitos fatores ambientais, como temperatura, umidade e precipitação. Além disso, fatores influenciados pelo homem, como a presença de produtos químicos na água e a possibilidade de doenças infecciosas, também têm impacto significativo. Os dados dos índices reprodutivos obtidos neste estudo são indispensáveis para futuras investigações de anomalias de incubação.

Pb-210 and composition data of near-surface sediments and interstitial waters evidencing anthropogenic inputs in Amazon River mouth, Macapa, Brazil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Changes in optical properties caused by UV-irradiation of aquatic humic substances from the amazon river basin: Seasonal variability evaluation

Aquatic humic substances (AHS) isolated from two characteristic seasons of the Negro river, winter and summer corresponding to floody and dry periods, were structurally characterized by (13)C nuclear magnetic ressonance. Subsequently, AHS aqueous solutions were irradiated with a polychromatic lamp (290-475 nm) and monitored by its total organic carbon (TOC) content, ultraviolet-visible (UV-vis) absorbance, fluorescence and Fourier transformed infrared spectroscopy (FTIR). As a result, a photobleaching upto 80% after irradiation of 48 h was observed. Conformational rearrangements and formation of low molecular complexity structures were formed during the irradiation, as deduced from the pH decrement and the fluorescence shifting to lower wavelengths. Additionally a significant mineralization with the formation of CO(2), CO, and inorganic carbon compounds was registered, as assumed by TOC losses of up to 70%. The differences in photodegradation between samples expressed by photobleaching efficiency were enhanced in the summer sample and related to its elevated aromatic content. Aromatic structures are assumed to have high autosensitization capacity effects mediated by the free radical generation from quinone and phenolic moieties.

Association of midazolam with ketamine in giant Amazon river turtles Podocnemis expansa breed in captivity

OBJETIVO: Avaliar os efeitos de duas associações anestésicas em tartarugas da Amazônia em (Podocnemis expansa). MÉTODOS: Vinte P. expansa, hígidas, de ambos os sexos, com massa corporal entre 1,0 e 1,5 kg, de um criatório comercial localizado no vale do rio Araguaia, Goiás, Brasil, foram distribuídas em dois grupos (G1 n=10 e G2 n=10). Cada grupo recebeu um protocolo sendo: P1 = midazolam (2 mg/kg IM) com cetamina (20 mg/kg IM) e P2 = midazolam (2 mg/kg IM) com cetamina (60 mg/kg IM), aplicados nos grupos G1 e G2, respectivamente. Os fármacos foram aplicados no membro torácico esquerdo. Os parâmetros clínicos avaliados foram: locomoção, relaxamento muscular, resposta aos estímulos dolorosos nos membros torácico direito e pelvinos e freqüência cardíaca. Essas avaliações foram feitas no tempo 0 (imediatamente após a injeção) e nos tempos 5, 10, 20, 30, 45, 60, 90, 120, 150 e 180 minutos após as injeções. RESULTADOS: O G2 apresentou maior freqüência cardíaca que o G1 e imobilização mais rápida e prolongada. CONCLUSÃO: As sedações obtidas por esses protocolos (P1 e P2) foram satisfatórias, sendo possível a contenção farmacológica para a coleta de amostras biológicas e exame físico em P. expansa.