The influence of captive breeding on the fatty acid profiles of Salminus hilarii (Characiformes: Characidae) eggs and larvae

In addition to the strong influence of the broodstock diet on the development and survival of offspring, domestication may also interfere with the larval life success. We obtained eggs from wild and domesticated Salminus hilarii females and domesticated males. Wild females were caught in the Tiete River and tributaries, and the domesticated females were born three years before the beginning of the experiment in the Ponte Nova Fish Farm. Animals from both groups were fed with the same feed to exclude feed variables. The eggs and larvae were sampled at 0, 8, 16, and 28?h after spawning (HAS), with the last sampling (28 HAS) coinciding with hatching time. After hatching, samplings proceeded at 32, 48, 66, and 96 HAS, with the last sampling (96 HAS) corresponding to the end of yolk sac consumption. Finally, the last experimental period was during the larvae exogenous feeding phase, at 102, 118, 166, and 214 HAS. Our data revealed that domestication of S. hilarii females influenced fatty acid (FA) metabolism during embryo and larva development. However, the structure of membrane phospholipid FA remained mostly stable, with changes principally in the neutral fraction. When the external conditions, mainly water and feed quality, remained constant, domestication of S. hilarii females did not significantly affect the structural FA composition but influenced the selectivity of consumption and/or storage of specific FA.     

The challenge of maintaining Atlantic forest biodiversity: A multi-taxa conservation assessment of specialist and generalist species in an agro-forestry mosaic in southern Bahia

Recent developments have highlighted the importance of forest amount at large spatial scales and of matrix quality for ecological processes in remnants. These developments, in turn, suggest the potential for reducing biodiversity loss through the maintenance of a high percentage of forest combined with sensitive management of anthropogenic areas. We conducted a multi-taxa survey to evaluate the potential for biodiversity maintenance in an Atlantic forest landscape that presented a favorable context from a theoretical perspective (high proportion of mature forest partly surrounded by structurally complex matrices). We sampled ferns, butterflies, frogs, lizards, bats, small mammals and birds in interiors and edges of large and small mature forest remnants and two matrices (second-growth forests and shade cacao plantations), as well as trees in interiors of small and large remnants. By considering richness, abundance and composition of forest specialists and generalists, we investigated the biodiversity value of matrix habitats (comparing them with interiors of large remnants for all groups except tree), and evaluated area (for all groups) and edge effects (for all groups except trees) in mature forest remnants. Our results suggest that in landscapes comprising high amounts of mature forest and low contrasting matrices: (1) shade cacao plantations and second-growth forests harbor an appreciable number of forest specialists; (2) most forest specialist assemblages are not affected by area or edge effects, while most generalist assemblages proliferate at edges of small remnants. Nevertheless, differences in tree assemblages, especially among smaller trees, suggest that observed patterns are unlikely to be stable over time.     

Hypnea musciformis: alternative or complement to the production of Kappaphycus alvarezii introduced in tropical countries?

Hypnea musciformis that are harvested from natural beds and introduced Kappaphycus alvarezii are the two main sources of raw material for the production of carrageenan in Brazil. The daily growth rate (DGR) and carrageenan yield (CY) of both species were evaluated in vitro and in the sea to assess the feasibility of cultivating H. musciformis as a complement or as an alternative to the production of K. alvarezii. The DGR of H. musciformis (10.8 ± 0.6% day^?1) was higher than the DGR of K. alvarezii (5.6 ± 0.3% day^?1) in vitro, and the CY extracted using NaOH (62.3 ± 0.15%) was better than using KOH (32.0 ± 0.3%). In eutrophic medium, the DGR of H. musciformis (9.4 ± 2.1% day^?1) was higher than that of K. alvarezii (5.0 ± 1.2% day^?1). However, in this condition, the CY was similar for both species (50.2 ± 3.5%), and both species were effective in removing nutrients (30% NH₄⁺, 18% NO^2? and 2.4% ). H. musciformis did not survive when cultivated in the sea, neither in monospecific nor in multispecific cultivation. Moreover, K. alvarezii grew better in monospecific cultivation throughout the year (from 1.73 to 5.15% day^?1) except during the wet period and the CY was high in both cultivation types (33.7–50.8%). We conclude that the cultivation of H. musciformis is not an alternative to K. alvarezii on the Brazilian southeastern coast. However, the results in vitro suggested its use as a complementary source of carrageenan or as a biological filter.     

Characterization of catalytic efficiency parameters of brain cholinesterases in tropical fish

Brain cholinesterases from four fish (Arapaima gigas, Colossoma macropomum, Rachycentron canadum and Oreochromis niloticus) were characterized using specific substrates and selective inhibitors. Parameters of catalytic efficiency such as activation energy (AE), k _cat and k _cat/k _m as well as rate enhancements produced by these enzymes were estimated by a method using crude extracts described here. Despite the BChE-like activity, specific substrate kinetic analysis pointed to the existence of only acetylcholinesterase (AChE) in brain of the species studied. Selective inhibition suggests that C. macropomum brain AChE presents atypical activity regarding its behavior in the presence of selective inhibitors. AE data showed that the enzymes increased the rate of reactions up to 10¹² in relation to the uncatalyzed reactions. Zymograms showed the presence of AChE isoforms with molecular weights ranging from 202 to 299 kDa. Values of k _cat and k _cat/k _m were similar to those found in the literature.     

Antioxidant Compounds Recovery from Juçara Residue by Thermal Assisted Extraction

This study aimed to recover bioactive compounds by solid-liquid extraction from the agro-industrial residue obtained during juçara fruits processing into pulp. A preliminary study using different solvents (methanol, ethanol and water) indicated ethanol in aqueous solution as the best solvent for antioxidants recovery. Then, a Box-Behnken design was applied considering as independent variables the solvent composition (30–70% ethanol in water), temperature (30–70 °C) and time (30–60 min), in order to evaluate the effects of these factors on antioxidant activity in juçara extract. Results showed that the extracts with higher antioxidant activity were obtained using 30% ethanol at 70 °C for 60 min; measurements included ABTS and DPPH assays, determination of total phenolic content and total monomeric anthocyanins. Furthermore, the effect of pH in antioxidants recovery was evaluated. For this purpose, the 30% ethanol solution was acidified to pH 1 and 2 with HCl. Principal component analysis showed the formation of three distinct groups: one characterized by high bioactive compounds content (pH 1.0), another with superior antioxidant activity (pH 5.75, non-acidified), and finally the group at pH 2 presenting the worst concentrations in the evaluated responses. HPLC analysis showed the presence of cyanidin-3-O-rutinoside and cyanidin-3-O-glucoside in the extracts. Therefore, the conventional solid-liquid extraction using renewable solvent can be successfully applied to recover bioactive compounds from juçara residue, which can be used by different food industries.     

Common Bean Productivity Following Diverse Boron Applications on Soil

Aspects related to micronutrients management are still poorly studied and need to be clarified to guarantee sustainable production. In this way, the study aimed to evaluate boron (B) fertilization effects on nutrition and production of common beans. The parameters measured were relative chlorophyll index, dry mass, boron transport, utilization and absorption efficiencies, B content, and B accumulation in plant tissues. The study showed that the dry mass production was negatively affected by B application, with linear dry mass decrease following the increase of B doses. Accordingly, it was found that the common bean cultivar Esplendor presented high absorption capacity of boron, and can reach 175 mg kg^?1. However, the high absorption caused phytotoxicity and reduced dry matter production by up to 30%, reflecting the efficiency of boron use by the plant, which was reduced in up to 75%.