efeito da aplicação de uma solução salina no crescimento e na composição química da atriplex nummularia

This study aimed to analyze the effect of a saline solution on growth and chemical composition of Atriplex nummularia, shrubby plant, absorbing salts used in the diet of animals and the management of water and saline soils. These plant seedlings were planted and grown in a reserved area at the Federal University of Rio Grande do Norte. The plantation was divided into two blocks, in which one of them was irrigated with saline solution with a concentration of 2840 mgL-1 of NaCl and the second group was irrigated with drinking water. After six months, the plants were collected, harvested and divided into three parts: leaf, thin and thick stem. Monthly, dimension measurements were carried out for cataloging the growth of Atriplex. Ion Chromatography (IC) and Optical Emission Spectroscopy Inductively Coupled Plasma (ICP-OES) were used to analyze the chemical composition of the partition plant parts. The results of these analyses revealed that an absorption process of anions and cations by Atriplex nummularia plant during its growth was achieved, in particular by a higher concentration of sodium and chloride ions. Scanning electron microscopy images showed and confirmed the presence of small crystals on the leaf surface. Electrical conductivity and pH measurements of the aerial parts of the plant were carried out and these results showed that the leaf is the plant part where there is a largest concentration of ions. In addition, measurements of specific surface were obtained from irrigated plants with saline solution, achieving higher surface area, in all cases. Plant dimensions obtained monthly showed that the plants irrigated with water grew 5% more than those plants irrigated with saline solution. Based on results obtained, Atriplex plant showed a higher potential to survive and adapt to environments (aquatic or geological) with high levels of salinity and this property can be used as a tool for removing salts/metals from industrial contaminated soils and effluents.

Influência de atividades antrópicas sobre a salinização da água em área de dunas no Município de Guamaré RN

The municipality of Guamaré is located on the north coast of RN, Salineira zone, with a land area of 259 km2 and a population of approximately 12,500 inhabitants (IBGE, 2010). Presents strong morphological instability caused mainly by the influence of human activities in the region. The present study aims to assess the existing levels of salts in the springs of the region, by evaluating the electrical conductivity, pH, salinity, chlorides, hardness, calcium, magnesium and heavy metals in the water. The collection and analysis methods adopted in the survey are based on APHA (2005). The electrical conductivity, salinity and chloride behaved similarly throughout the study. Some points suffered the direct effect of the salt ponds and others. Given the existence of a drainage ditch between the saline and monitored region, there was little change in the environment, including the native vegetation. The opposite situation occurred in farms where the region is fully committed local vegetation and water holes and wells used in the past for domestic use are practically disabled (high salt content). In Rio Miassaba formation of an estuary is reversed, with the farther out from the sea showing higher salt concentracions, which may be associated with the discharge of organic matter and natural evaporation rate. In periods of no rainfall had a few points higher than the levels of salts found in seawater and may be associated with high evaporation in the region. Detected a positive factor is the high resilience and reducing salt, after periods of rainfall incidence

Obtenção e Caracterização Físico-Química do Sistema Compósito PEG-TiO2

Hybrid systems formed from polymers and transition metals have now their physical and chemical properties extensively investigated for use in electronic devices. In this work, Titanium Dioxide (TiO2) from the precursor of titanium tetrabutoxide and the composite system Poly(Ethylene Glycol)-Titanium Dioxide (TiO2-PEG) were synthesized by sol-gel method. The PEG as acquired and TiO2 and composites powders were analyzed by X-Ray Diffraction (XRD), Spectroscopy in the Infrared region with Fourier transform (IRFT), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). In the XRD analysis were observed in the TiO2 crystal faces of one of its polymorphs - anatase phase, crystal planes in Poly (Ethylene Glycol) with considerable intensity and in the composite systems the mixture of crystal faces of their precursors isolated and reduction of crystallinity. The TG / DTG suggested increasing the thermal instability of PEG in the composite powders as TiO2 is incorporated into the system. Spectral analysis presented in the infrared overlapping bands for the polymer and metal oxide, reducing the intensity of symmetric stretching of ligand groups in the main chain polymer and angular deformations; were observed using SEM micrographs of the morphological changes suffered by composite systems with the variation of the oxide concentration. Analyses by impedance spectroscopy indicated that the increased conductivity in composite occurs in line with the addition of the metal oxide concentration in the composite system

Obtenção de sistemas microemulsionados e estudo de simulação por dinâmica molecular de sistemas micelares objetivando a veiculação de produtos naturais bioativos

Among the new drugs launched into the market since 1980, up to 30% of them belong to the class of natural products or they have semisynthetic origin. Between 40-70% of the new chemical entities (or lead compounds) possess poor water solubility, which may impair their commercial use. An alternative for administration of poorly water-soluble drugs is their vehiculation into drug delivery systems like micelles, microemulsions, nanoparticles, liposomes, and cyclodextrin systems. In this work, microemulsion-based drug delivery systems were obtained using pharmaceutically acceptable components: a mixture Tween 80 and Span 20 in ratio 3:1 as surfactant, isopropyl mirystate or oleic acid as oil, bidistilled water, and ethanol, in some formulations, as cosurfactants. Self-Microemulsifying Drug Delivery Systems (SMEDDS) were also obtained using propylene glycol or sorbitol as cosurfactant. All formulations were characterized for rheological behavior, droplet size and electrical conductivity. The bioactive natural product trans-dehydrocrotonin, as well some extracts and fractions from Croton cajucara Benth (Euphorbiaceae), Anacardium occidentale L. (Anacardiaceae) e Phyllanthus amarus Schum. & Thonn. (Euphorbiaceae) specimens, were satisfactorily solubilized into microemulsions formulations. Meanwhile, two other natural products from Croton cajucara, trans-crotonin and acetyl aleuritolic acid, showed poor solubility in these formulations. The evaluation of the antioxidant capacity, by DPPH method, of plant extracts loaded into microemulsions evidenced the antioxidant activity of Phyllanthus amarus and Anacardium occidentale extracts. For Phyllanthus amarus extract, the use of microemulsions duplicated its antioxidant efficiency. A hydroalcoholic extract from Croton cajucara incorporated into a SMEDDS formulation showed bacteriostatic activity against colonies of Bacillus cereus and Escherichia coli bacteria. Additionally, Molecular Dynamics simulations were performed using micellar systems, for drug delivery systems, containing sugar-based surfactants, N-dodecylamino-1-deoxylactitol and N-dodecyl-D-lactosylamine. The computational simulations indicated that micellization process for N-dodecylamino-1- deoxylactitol is more favorable than N-dodecyl-D-lactosylamine system.

A comunidade zooplanctônica como bioindicadora do estado trófico de reservatórios da região semiárida tropical

E utrophication in continental aquatic ecosystems and the following deterioration of water quality are some of the greatest problems to be solved in this century. Due to their own peculiarities reservoirs from semi - arid regions constitute a great challenge to water management because of their greater vulnerability to eutrophication process. I dentification of biolo gical community components that may be used as bioindicators is important to allow an early detection of adverse changes, and also to provide subsidies for management and conservation actions. The aim of the present study is to evaluate the potential of zo oplankton community as bioindicator of the trophic state of two reservoirs belonging to the Piranhas - Açu basin, RN, Brazil: Boqueirão de Parelhas and Passagem das Traíras. Monthly sampling s of both systems were carried out in both systems during the period of January to December. Measurements were performed for temperature, pH, dissolved oxygen and water electrical conductivity besides water samples collection for nutrients, suspended solids, chlorophyll - a and zooplankton analyses. T axonomic composition of zooplankton , density and biomass were analysed. Trophic state index, ABC curves , W statistic and the Calanoida: Cyclopoida ratio were also obtained. The results evidenced that Boqueirão de Parelhas reservoir was a mesotrophic sy stem, and Passagem das Traíras r eservoir was eutrophic. In both reservoirs zooplankton community had low species richness, mostly constituted by tolerant species which have wide geographical distribution, as well the dominance of the rotifers Brachionus havanaensis , B. calyciflo rus and Keratella tropica ; of the calanoid copepods Notodiaptomus cearensis and N. iheringi ; cyclopoid copepod Thermocyclops decipiens, and of the cladocerans Ceriodaphnia cornuta and Diaphanosoma spinulosum . Among the biological indices the ABC curves fo r the zooplankton community indicated a moderate dis turbance in both reservoirs, th e Calanoida: Cyclopoida ration indicated not impacted environments , e xcept during the end of the study to the reservoir Passagem das Traíras . It was concluded that the indices used are good indicators of disturbance and alteration in the community, however they are not good indicators for monitoring the trophic state of the studied reservoirs due to the simultaneous occurrence of other factors selecting species, as the c oncentration of ions and high turbidity, which are part of the reservoir characteristics of semiarid.

Desenvolvimento de emulsões o/a contendo extrato glicólico de açai e avaliação da atividade fotoprotetora

Sunscreen use is the most common photoprotection alternative used by the population, and so these products should offer improved protection with broad - spectrum, UVA and UVB protection . Vegetal substances have recently been considered as resources for sunscreen formulations due to their UV spectrum absorption and antioxidant properties. The Euterpe oleracea Mart., popularly known as açai, in its che mical composition contain polyphenols compounds, such as anthocyanins and flavonoids , to which antioxidant properties have been attributed . The aim of this work was to develop O/W sunscreens emulsions con taining açai glycolic extract ( AGE) and to evaluate both their physical stability , safety and photoprotective efficacy. The safety of the extract was evaluated by in vitro phototoxicity and cytotoxicity tests. Emulsions containing AGE and sunscreens were formulated using different types and concentrations o f polymeric surfactant (Acrylates/C 10 - 30 Alkyl Acrylate Crosspolymer and Sodium Polyacrylate). The influence of two rheology modifiers (Polyacrylamide (and) C13 - 14/Isoparaffin (and) Laureth - 7 and Carbomer) on the stability was also investigated. Physical stability was evaluated by preliminary and accelerated studies. The macroscopic analyses, pH value and electrical conductivity determinations and rheological behavior were evaluated at different time intervals . The in vivo Sun Protect Factor ( SPF ) was determined according to the International Sun Protection Factor Test Method – 2006 and UVA Protection Factor (FPUVA), wavelength critical and reason SPF/FPUVA were performed according to the method Colipa 2011. The extract did not present cytotoxic ity and phototoxic ity . The stable emulsion containing 5% glycolic extract of açai and 1.0% of sodium poliyacrylate showed pseudoplastic and thixotropic behavior . The sunscreen emulsion containing açai glycolic extract showed a SPF 25.3 and PF - UVA = 14.97. Whe n açai glycolic extract was added in the emulsion sunscreen, no significant increase in the in vivo SPF and FPUVA values were observed. This emulsion showed 1.69 of the SPF/PF - UVA ratio and a critical wavelength value of 378 nm, so may therefore be conside red a sunscreen with UVA and UVB protection.

Análise da problemática socioambiental de nascentes urbanas no município de Garanhuns-PE

Garanhuns City, in Pernambuco, undergoes a rapid, polluting and non-organized urban development affecting its freshwater springs around the urban environment. These sources are of great importance to the district as well as to the hydrographic basin of the Mundaú River. In this view, this paper aims at analyzing the socio-environmental problems resulting from the urban expansion surrounding the Garanhuns’ sources. The study considers the social and environmental dynamics and follows the theoretical contributions of socio-environmental geography proposed by Mendonça’s Urban Environmental System methodological and theoretical model (2004), as well as the conceptual values of Santos’ space theory (2002a). The data treatment included bibliographical and documental research, evaluation of environmental impact, and water analysis. It revealed that Garanhuns possesses many local environmental traits favoring the coming out of freshwater springs and that these sources have played an important role in the making and development of that village. The environmental impacts on freshwater springs, like Olho D’água, Bom Pastor, Vila Maria, Pau Amarelo and Pau Pombo have been evaluated through the environmental impact score IIAN. It put alight serious cases of socio-environmental impacts on the dynamics of the freshwater springs. In the period of April 2013 and April 2014, it monitored the superficial water quality expelled by the Pau Pombo, Pau Amarelo e Vila Maria water sources, and the analyses of the contents followed the determinations of the Environmental National Board, whose parameters are dissolved oxygen, biochemical demand of oxygen, nitrate, total coliforms, faecal coliforms, and electrical conductivity. The results recollected suggest the existence of organic pollution and deep alteration in the water coming out from the sources. In consequence, it seems important the putting out of measures destined to stop those impacts and guaranteeing protection and maintenance of the freshwater springs and their micro-basins.

Influência de eventos hidrológicos extremos na qualidade da água de reservatórios na região tropical semiárida

Reservoirs are artificial ecosystems, intermediate between rivers and lakes, with diferent morphological and hydrological characteristics that can provide many important benefits to society. However, the use of this water for human consumption, watering livestock, leisure, irrigated agricultural production and pisciculture development, directly influence the increase loading of nutrients to aquatic environments and contribute to acceleration of eutrophication. Furthermore, global climate models are predicting a higher occurrence of extreme events such as floods and severe droughts, which will create hydrological stresses in lakes. In the semiarid northeast we can see the occurrence of these events, the drought of the years 2012, 2013 and 2014 was the worst drought in 60 years, according to the National Water Agency (ANA). Thus, this study aimed to evaluate the quality of the semiarid tropical water sources, identifying temporal patterns in periods with extreme hydrological events (floods and severe droughts). The study results showed that Gargalheiras and Cruzeta reservoirs presented significative changes in the limnological variables between rain and severe drought periods, with better appearance and in the most of the water quality variables in the rainy season and higher nutrientes concentrations and high electrical conductivity values in severe season, indicating decay of its quality. However, we found diferent behaviors between the reservoirs in severe drought. While Gargalheiras showed a typical behavior of the region, with high concentrations of algal biomass, indicating the worsening eutrophication, Cruzeta demonstrated a colapse in the total phytoplankton biomass, evidenced by the decrease in chla concentrations. This fact occurred because the low depth and proximity with the sediment facilited the inorganic solids resuspension and, consequently, resulted in turbid water column and light by limitation. In addition, the different behaviors between the reservoirs indicate that the responses of these environments problems such as extreme events must take into account factors such the region climate, size, depth of the reservoir and the basin characteristics.

Estudo sobre a relação entre a atividade geomagnética e cintilações de sinais de GPS em Natal-RN (Brasil)

To identify the relationship between GPS scintillation in Natal-RN (Brazil) and geomagnetic disturbances of any intensities and variations, this work made analysis of the ionospheric behavior and magnetic indexes (Dst , AE and Bz of the interplanetary magnetic field) concerning to different periods of the solar cycle between 2000 and 2014. Part of the data of this research originated at the UFRN observatory, from a GEC Plessey board connected to an ANP -C 114 antenna, modified by Cornell University’s Space group Plasma Physics in order to operate the ScintMon, a GPS monitoring program. This study, therefore, found several cases of inhibited scintillations after the main phase of magnetic storms, a fact that, along with others, corroborated with categorization of Aarons (1991) and models of disturbed dynamo (according to Bonelli, 2008) and over-shielding penetration, defended by Kelley et al. (1979) and Abdu (2011) [4]. In addition to these findings, different morphologies were noted in such disruptions in the GPS signal in accordance with previous magnetic activities. It also found a moderate relationship (R2 = 0.52) between the Dst rate (concerning to specific time) and the average of S4 through a polynomial function. This finding therefore, corroborating Ilma et al. (2012) [17], is an important evidence that the scintillation GPS are not directly controlled by magnetic induction of storms. Completing this work, this relation did show itself as a way of partial predicting of scintillations.

Ocorrência de leite instável na região semiárida do Rio Grande do Norte e sua correlação com a qualidade do leite

The unstable non acid milk (UNAM) is characterized by coagulation in the alcohol test and wanted acidity (14-18°D). Among Brazilian regions, the South and Southeast have the highest occurrence of LINA, which has been causing problems for both producers and for industries, due to the disposal or undervaluation of milk. In the Northeast there are few studies that indicate their occurrence and quality. The objective of this study was to identify the occurrence of unstable non-acid milk in the west and central mesoregions of Rio Grande do Norte, determine their physicochemical characteristics, test alcoholic graduations and evaluate their correlation with the quality of milk. 176 raw milk samples were analyzed in the period from September to December /2014 from 23 APASA’s cooling tanks, located in 7 cities of west and central mesoregions RN. The samples were collected in duplicate, one sample used for alcohol testing at 68, 72 and 76%, measurement of pH, acidity, electrical conductivity and boiling proof, made in LABOLEITE / UFRN; and the other sample containing Bronopol® preservative, was sent to the APCBRH (Cattle Breeders Association Paranaense Holstein) laboratory in Curitiba-PR, which were analyzed fat, protein, total solids, lactose, casein, urea nitrogen and somatic cell count. The test alcohol samples disapproved 31.82%, of which 30% proved to be non-acid, and 30% had high acidity. The samples were divided into three classes: Stable Milk, UNAM and acid milk. 3% Tukey test was used for comparison of stable milk components and UNAM and there was no significant difference between them. Both classes obtained averages within the standard required by IN 62. The average value of electric conductivity was 4.84 mS/cm for stable milk, 4.55 mS/cm for unstable and acid milk and 4.53 mS/cm for non-acid unstable milk. The electrical conductivity was positively correlated with alcohol stability of milk and negative correlation with acidity and pH. Could not observe direct relationship between the electrical conductivity and the somatic cell count.The boiling test was negative for all samples UNAM. It can be concluded that the incidence of UNAM in the studied region is low, although the predisposing factors such as heat stress, drought and nutritional deficiency. In conclusion, the UNAM has quality similar to stable milk, conform the norms required by Agriculture Ministry, and with adequate thermal stability, which proves that there is no reason to reject this milk by industry.

Influência da pressão e da vazão de concentrado sobre o desempenho de ultrafiltração no pós-tratamento de esgotos

Despite the numerous advantages resulting from the use of membrane filters technology, intrinsic limitations fouling process become relevant to its applicability. The control of operating conditions is an important tool to mitigate fouling and achieve good levels of efficiency. In this sense, the objective of this study was to investigate the effect of transmembrane pressure and concentrate flow in the performance of ultrafiltration, applied to the post-treatment of domestic sewage. The process was evaluated and optimized by varying the pressure (0.5 and 1.5 bar) and the concentrate flow (300 and 600 L/h), using a 22 factorial design, in order to investigate the effects on the permeate flow and quality of effluents generated at each operating condition. We evaluated the following quality indicators for permeate: pH, electrical conductivity, total suspended solids, turbidity, calcium and Chemical Oxygen Demand (COD). In all tests, we observed marked reduction in the permeate flux at the early stages, followed by a slow decline that lasted until it reaches a relatively constant level, around 120 minutes of filtration. The increased pressure resulted in a higher initial permeate flux, but the decrease of the flow with time is greater for tests at higher pressure, indicating a more pronounced fouling process. On the other hand, increasing the concentrate flow resulted in a slower decline in permeate flux with the filtration time. Regarding the quality of permeate, the transmembrane pressure of 0,5 bar was the one that allowed better results, and was statistically confirmed through the two-way ANOVA test with repeated measures, significant effect of pressure on the turbidity of the permeate. The concentrate flow, in turn, showed no significant influence on any of the quality parameters. Thus, we conclude that, from an economic and environmental point of view, it is more interesting to operate ultrafiltration membrane system with a lower concentrate flow associated with a low transmembrane pressure, since under these conditions will produce less waste, and the permeate will present lower concentrations of the analyzed constituent, especially lower turbidity.

Testes para a avaliação da qualidade fisiológica de sementes de Moringa oleifera Lam

The evaluation of seed vigor is an important factor for detection of lots of high quality seeds, so that development of procedures to evaluate the physiological potential has been an important tool in quality control programs seeds. In this sense the study aimed to adapt the methodologies of accelerated aging, electrical conductivity and potassium leaching to evaluate Moringa oleifera seed vigor LAM.. Therefore, four lots of moringa seeds were subjected to the germination tests, seedling emergence, speed of emergence index, emergence first count, length and dry mass of seedlings and cold test for their physiological characterization, in addition to accelerated aging, electrical conductivity and potassium leaching. The experimental design was completely randomized with four replications of 50 seeds and the means compared by Tukey test at 5% probability. For accelerated aging the periods were studied aging 12, 24 and 72 hours at 40, 42 and 45°C. For the electrical conductivity test was used to a temperature of 25°C for periods of 4, 8, 12, 16 and 24 hours of immersion in 75 to 125 mL of distilled water, using 25 to 50 seeds, and for potassium leaching test samples were used 25 to 50 seeds, placed in plastic cups containing 70 and 100 mL of distilled water at 25°C for periods of 1, 2, 3, 4, 5 and 6 hours. From the results obtained, it can be inferred that the methods best fit for the accelerated aging test Moringa seeds were a temperature of 40°C for 12 to 72 hours, 42°C 72 hours 45°C 24 hours . In the electrical conductivity test Moringa seeds, the combination of 50 seeds in 75 mL distilled water for a period of immersion of 4 hours and 50 seeds in 125 mL of 4 hours were efficient for the differentiation of lots of Moringa seeds as to vigor and for potassium leaching test moringa seeds, the combination of 50 seeds in 100mL of distilled water allowed the separation of lots of four levels of vigor, at 2 hours of immersion, showing promise in evaluate the quality of moringa seeds.

Testes para a avaliação da qualidade fisiológica de sementes de Moringa oleifera Lam

The evaluation of seed vigor is an important factor for detection of lots of high quality seeds, so that development of procedures to evaluate the physiological potential has been an important tool in quality control programs seeds. In this sense the study aimed to adapt the methodologies of accelerated aging, electrical conductivity and potassium leaching to evaluate Moringa oleifera seed vigor LAM.. Therefore, four lots of moringa seeds were subjected to the germination tests, seedling emergence, speed of emergence index, emergence first count, length and dry mass of seedlings and cold test for their physiological characterization, in addition to accelerated aging, electrical conductivity and potassium leaching. The experimental design was completely randomized with four replications of 50 seeds and the means compared by Tukey test at 5% probability. For accelerated aging the periods were studied aging 12, 24 and 72 hours at 40, 42 and 45°C. For the electrical conductivity test was used to a temperature of 25°C for periods of 4, 8, 12, 16 and 24 hours of immersion in 75 to 125 mL of distilled water, using 25 to 50 seeds, and for potassium leaching test samples were used 25 to 50 seeds, placed in plastic cups containing 70 and 100 mL of distilled water at 25°C for periods of 1, 2, 3, 4, 5 and 6 hours. From the results obtained, it can be inferred that the methods best fit for the accelerated aging test Moringa seeds were a temperature of 40°C for 12 to 72 hours, 42°C 72 hours 45°C 24 hours . In the electrical conductivity test Moringa seeds, the combination of 50 seeds in 75 mL distilled water for a period of immersion of 4 hours and 50 seeds in 125 mL of 4 hours were efficient for the differentiation of lots of Moringa seeds as to vigor and for potassium leaching test moringa seeds, the combination of 50 seeds in 100mL of distilled water allowed the separation of lots of four levels of vigor, at 2 hours of immersion, showing promise in evaluate the quality of moringa seeds.

Ecologia alimentar e reprodutiva da piaba-do-rabo-amarelo, Astyanax cf. lacustris (Reinhardt, 1874) (Osteichthyes: Characidae) na Lagoa do Piató, Assu, Rio Grande do Norte, Brasil

The feeding habits and biological aspects of the reproductive cycle of two-spot astyanax, Astyanax cf. lacustris (Reinhardt, 1874) were investigated. Fish samples were captured on a monthly basis, using gillnets of 4 cm mesh size, from the Piató Lake, Assu, Rio Grande do Norte, during the period of September, 2006 to August, 2007. Physico-chemical parameters, such as, temperature, electrical conductivity and dissolved oxygen of the lake were registered. The monthly values of rainfall also were obtained. The 360 individuals captured, were measured, weighed, dissected, and stomach weight and the stage of gonadal maturity were registered. The stomach contents analyses were carried out based on volumetric method, points, frequency of occurrence and applying the Index of Relative Importance. The degrees of repletion of the stomachs were determined besides the Index of Repletion relating to feeding activity variations and frequency of ingestion with limnological parameters and rainfall. The food items identified were separated into distinct groups according to their origin. Sex ratio and Gonadosomatic Relation of females were verified to determine the spawning period and fecundity. The physico-chemical parameters presented the following annual mean values: temperature = 28.8ºC, electrical conductivity = 992.5 µS.cm-1; dissolved oxygen = 4.9 mg.L-1 during the study period. The annual mean of the rainfall was 63.5 mm. The results indicate that this species present an omnivorous feeding habit with a tendency towards insectivory, with an increase in feeding activity during the dry season. The aquatic oxygen to interfere very importance in the feeding activity than the others factors physico-chemicals of water and rainfall. There was a predominance of females, with a sex proportion of 1M:7F. The macroscopic characteristics of the ovaries and testicles revealed four stages of gonadal development: immature, maturing, mature and spent. A temporal variation was observed for the gonadal development of males and females. There was reproductive activity through out the year, with peaks in the months of February, April and June to correspond with the rain of precipitation of the region. The mean fecundity was 7.681 mature oocytes, varying from 4.476 to 12.036, with mean of 7.681. There was positive relation between fecundity and body mass. Condition Factor is not an efficient indicator of the reproductive period of this species. The species A. cf. lacustris is an opportunist and is well adapted to the conditions of the semi-arid Caatinga Biome

Diversidade Ictiofaunística e Ecologia reprodutiva de uma espécie nativa de peixe da Bacia Piranhas-Assu, RN

The Caatinga biome is rich in endemic fish species fauna. The present study the results of fish faunal surveys conducted in the hydrographic basin of Piranhas-Assu of the Brazilian Caatinga biome. The fish samples collected were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families (Characidae, Curimatidae, Auchenipteridae, Anostomidae, Prochilodontidae, Erythrinidae, Cichlidae, Sciaenidae, Heptapteridae, Loricariidae, Synbranchidae) and 22 species, of which 17 are endemic and five have been introduced from other basins. The order Characiformes was the most representative in number of species (46,35% ) followed by Perciformes (35,38%), Siluriformes (17,44%) and Synbranchiformes (0,5%). The Nile tilapia, Oreochomis niloticus, the only exotic species, was most expressive in number of individuals (24.92%) followed by the native species piau preto, Leporinus piau (18,77 %). Considering the relative frequency of occurrence of the 22 species, 13 were constant, five were accessory and four were occasional. This study investigated the reproductive ecology of an endemic fish black piau, Leporinus piau from the Marechal Dutra reservoir, Acari, Rio Grande do Norte. Samplings were done on a monthly basis from January to December 2009, and a total of 211 specimens were captured. The environmental parameters such as rainfall, temperature, pH, electrical conductivity and dissolved oxygen of water were recorded. The sampled population showed a slight predominance of males (55%), however females were larger and heavier. Both sexes of L. piau showed positive allometric growth, indicating a higher increase of weight than length. The first sexual maturation of males occurred at smaller size, with 16.5 cm in total length than females (20.5 cm). During the reproductive period, the condition factor and gonadosomatic index (GSI) of L. piau were negatively correlated. This species has large oocytes with a high mean fecundity of 54.966 with synchronous oocyte development and total spawning