Ecologia parasitária de isópodos e biologia reprodutiva em tibiro, Oligoplites spp (OSTEICHTHYES: CARANGIDAE) das águas costeiras de Natal, Rio Grande do norte

Oligoplites palometa (Cuvier) and Oligoplites saurus (Bloch & Schneider) (Osteichthyes: Carangidae) are coastal pelagic fish species. The objective of this study was to investigate the effect of parasitism by isopods and the reproductive biology of the leather jack, Oligoplites spp. A total of 113 individuals of Oligoplites spp (35 of O. saurus and 78 of O. palometa) were captured during the period between January, 2005 and July, 2007 from the coastal waters of Natal, RN. The morphometric and meristic characters were registered; macroscopic analyses were done to collect the isopod parasites and the gonads were observed to verify the reproductive aspects. The crustacean isopod parasite, Cymothoa spinipalpa (Isopoda: Cymothidae) was encountered on the tongue in the oral cavity in both fish hosts. The parasitic indices of C. spinipalpa showed high values of prevalance of 51,4% for O. saurus and 64,1% for O. palometa. The host presented significant correlations between body mass and body length of O. palometa and the number of parasites. Body lengths of female C. spinipalpa were small due to the limited space available in the oral cavity of the host. There was a significant difference in the sex ratio of O. palometa, males outnumbered the females. The isopod parasites showed specificity to the oral cavity of hosts. Macroscopic analyses of gonads showed four stages of gonadal development for both sex of O. palometa: immature, maturing, mature and spent

Potencial larvicida de extratos de plantas regionais no controle de larvas de Aedes aegypti

Dengue, amongst the virus illnesses one can get by vectorial transmission, is the one that causes more impact in the morbidity and mortality of world s population. The resistance to the insecticides has caused difficulties to control of vector insect (Aedes aegypti) and has stimulated a search for vegetables with larvicidal activity. The biodiversity of Caatinga is barely known and it is potential of use even less. Some plants of this biome are commercialized in free fairs northeast of Brazil, because of its phytotherapics properties. The vegetables in this study had been selected by means of a questionnaire applied between grass salesmen and natives of the Serido region from Rio Grande do Norte state; culicids eggs had been acquired with traps and placed in container with water for the larva birth. Thirty larvae had been used in each group (a group control and five experimental groups), with four repetitions four times. The vegetables had been submitted to the processes of decoction, infusion and maceration in the standard concentration of 100g of the vegetable of study in 1l of H2O and analyzed after ½, 1, 2, 4, 8, 12, 24 and 48 hours for verification of the average lethal dose (LD50) from the groups with thirty larva. The LD50 was analyzed in different concentrations (50g/l, 100g/l, 150g/l, 200g/l e 300g/l) of Aspidosperma pyrifolium Mart. 48 extracts of rind, leaf and stem of the seven vegetal species: Aspidosperma pyrifolium Mart., Mimosa verrucosa Benth, Mimosa hostilis (Mart.) Benth., Myracrodruon urundeuva Allemão, Ximenia americana L, Bumelia sartorum Mart Zizyphus joazeiro Mart, had been analyzed. The extracts proceeding from the three methods were submitted to the freezedrying, to evaluate and to quantify substances extracted in each process. The results had shown that Aspidosperma pyrifolium Mart. and Myracrodruon urundeuva Allemão are the species that are more distinguished as larvicidal after 24 hours of experiment, in all used processes of extraction in the assays. The Zizyphus joazeiro Mart species has not shown larvicidal activity in none of the assays. In relation to the extraction method, the decoction was the most efficient method in the mortality tax of the A. aegypti larvae

Biologia reprodutiva da |Tainha, Mugil curema valencientes, 1836 (osteichthyes: mugilidade) nas águas costeiras do Rio Grande do Norte

The marine fish white mullet, Mugil curema Valenciennes, 1836 (Osteichthyes: Mugilidae) exhibits a wide geographical distribution, being common in the Brazilian coast and is an important component of the artisanal fisheries. The objective of this study was to investigate the reproductive biology of M. curema in the coastal waters of Rio Grande do Norte. Fish samples were captured on a monthly basis during August, 2008 to July, 2009. The fish specimens were numbered, weighed, measured, dissected and their gonads were removed, weighed, their sex and gonadal development were identified. The length-weight relationship was determined for males and females. The sex ratio, the size at first gonadal maturation and gonadosomatic index (GSI) were calculated and ovarian development was investigated using macroscopic and histological techniques. The fecundity, spawning type and the reproductive period of the species were determined. A total of 366 specimens (186 males and 180 females) were captured. The sex ratio was 1:1 and the females were heavier than males. The estimated values of the angular coefficient for both sexes suggest that the species has isometric growth. The size at which 50% of the population began the process of maturation was 25.9 cm of total length for grouped sex. The macroscopic characteristics of the ovaries showed four stages of development: immature, maturing, mature and spent. However, the microscopic characteristics of the ovaries showed five stages of development: immature, early maturing, late maturing, mature and spent. The development of oocytes indicated five phases: Chromatin-nucleolus (phase I), initial perinucleolar (phase II), final perinuclear (phase II), formation of vitelline vesicle or yolk (phase III), vitellogenic (phase IV) and complete vitellogenesis (phase V). The species has a prolonged spawning period, with two peaks coinciding with the rainy season.

Biologia alimentar e morfohistologia do tubo digestório do mussum, synbranchus marmoratus, bloch (osteichthyes: synbranchidae) no açude Marechal Dutra Gargalheiras , localizado no semi-árido brasileiro

Food habits and morpho-histology of the digestive tract of marbled swamp eel, Synbranchus marmoratus (Block, 1917) were investigated. The fish samples were captured during August, 2007 to July, 2008 in the Marechal Dutra reservoir, Acari, Rio Grande do Norte. The rain fall data was obtained from EMPARN. The fish captured, were measured, weighed, dissected, eviscerated and individual stomach weights 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 during the rainy and dry seasons. The rainfall varied from 0 mm a 335 mm with a mean value of 71.62 mm. Highest rainfall of 335.5 mm was registered in March, 2008 and August to December was the dry period. During the dry period the study species presented high degrees of repletion of the stomachs, with a peak value in the month of September (mean = 4.54; ± SD = 0.56). The minimum mean value of = 3.99 ± SD = 0.25 was registered in the month of May during the rainy period. The stomach contents of S. marmoratus registered show that this fish prefers animals, 78.22% of crustaceans 2.85% of mollusks, 3.25% of fish, 1.4% of insects and 13.5% of semi-digested organic matter, thus characterizing the study species as a carnivore with a preference for crustaceans. The morpho-histological aspects of the digestive tract of S. marmoratus indicate that the mouth is terminal adapted to open widely, thin lips with taste buds, small villiform teeth forming a single series on maxillas, four pairs of branchial arches with short and widely spaced branchial rays. The oesophagus is short and cylindrical with a small diameter. The oesophagus wall is thick with mucas surface and internal parallel folds. The stomach is retilinical in form, presenting cardiac, caecal and pyloric portions. The caecal portion is long and is intermediary in position between the cardiac and pyloric portions. The cardiac portion of the stomach is short and cylindrical formed of simple epithelial cylindrical mucus cells. The caecal portion is long with narrow walls, a big cavity and smaller folds which give rise to gastric glands. The phyloric portion has no glands and primary or secondary mucas folds. The morphohistological aspects of the digestive tract of S. marmoratus indicate its adaptation to a carnivorous feeding habit

Estudo epidemiológico das parasitoses oculares na população de escolares da cidade de Natal-RN, Brasil

The objective of this study is to estimate the prevalence of Ocular Toxocariasis, Diffuse Unilateral Subacute Neuroretinitis (DUSN), Toxoplasma gondii infection and Ocular Toxoplasmosis in a student population in Natal-RN/Brazil and relate it to demographic, epidemiologic and socio-economic risk factors. The incidence of DUSN was observed in patients at the Federal University of Rio Grande do Norte Ophthalmology Service and the Prontoclinica de Olhos Ophthalmology clinic in Natal. In cases where a worm was found in the subretinal space, the result of treatment with photocoagulation using Green Laser (Eye Light ALCON) was evaluated in relation to final visual result. The sample was randomly selected among the schools of the four districts of Natal, according to the type of institution (public or private), its level (elementary or secondary), and study period (morning, afternoon or evening). The school population was studied from March to May, 2001. Initially, the students answered a questionnaire to evaluate demographic, epidemiologic and socio-economic risk factors. Afterwards, the following procedures were carried out: blood samples were taken for Toxoplasmosis (IgG, IgM) serology, hemogram, ophthalmological examination, consisting of clinical history, measurement of visual acuity, refraction under cycloplegia, biomicroscopy of the anterior segment and annexa, funduscopy and examination of extrinsic motility. The prevalence of Toxocariasis was 0.2% or 2 per one thousand students. The sample was insufficient to estimate the prevalence of DUSN. Seventy patients with DUSN diagnosis were examined from January, 2001 to January, 2003. A live worm was found in the subretinal space of all four patients in the acute phase, and these were treated with laser photocoagulation. After follow-up (average = 11.5 months), visual acuity improved in three eyes and remained unaltered in one eye. Worms were found in 22 of the 66 patients in the chronic phase, and these also were treated with laser photocoagulation. After a follow-up period of 13.1 months, on average, visual acuity improved in two of the patients, remained unchanged in 19 and worsened in one. The comparison of visual result before and after treatment was not statistically significant (p = 0.302). The diagnosis of DUSN in the acute phase, followed by prompt localization and destruction of the worm by photocoagulation, can improve the patient s vision. However, destruction of the worm by laser photocoagulation in eyes with DUSN in the chronic phase does not improve visual acuity. Seroprevalence for IgG was 46% (Confidence Interval CI 95%-42.9-49.2%) and for IgM it was 1.4% (CI 95% = 0.8-2.4%). The prevalence of ocular lesion was 1.15% (CI 95% = 0.6 - 2.0%). Socio-economic conditions were determinants in the prevalence of Systemic and Ocular Toxoplasmosis in the bivaried analysis and confirmed in the multivaried analysis (mother s scholarity illiterate/ OR = 2.9 and p < 0.001). The T. gondii infection prevalence, although high, was less than that found in studies performed in the South and Southeast of Brazil and that of Ocular Toxoplasmosis was completely discrepant, varying from 5 to 17 times less. Although important epidemiological variables such as owning a cat, drinking unfiltered water, and coming into contact with rivers or lakes showed an association in the preliminary analysis, they lost their influence when included in the logistic model. Future studies are scheduled to begin in March, 2004, in collaboration with other Brazilian and American universities in an attempt to discover the reason for these findings, as well as identifying the different strains of Toxoplasma gondii, and studying the sources of water utilized by the population of Natal Brazil

O erotismo mítico da ninfeta

This dissertation establishes a viewpoint in the Social Cience Field of the Nymphs image in the romanesque construction of the twentieth century based in modern archaeology. Our literary corpus is constitututed by the book of the russian author callled Wladimir Nabokov entlited Lolita and the book Presença de Anita, from a brazilian author called Mario Donato. Both works had a singular repercussion involving an erotic conception wich was faced as pornographic and baffling. We appeal to Georges Bataille‟s and Foucault‟s discussion in order to observe it through an erotic viewpoint from an inner experience not submitted to normalizations. Such experiences provoke a feeling of something unknown and it reflects wild singularities proposed by Foucault and related with many misunderstanding things presented in institutions and cultures. Furthemore Bataille‟s conception about erotism will give us conditions to analyze nymphs‟ bodies in order to see themselves from their main characteristics, such as seduction and tempting and maligning forces. We still aim to focus the paradigm of mankind and nature in the direction presented by Edgar Morin. He analyzes some feelings that nymphs provoke and their relation between men and death. In adittion, we present in this issue some questions between culture and biology, focusing on the initial period of larva (wich means the beggining), bringing up what is ready to be born, a mythical and significant body shown in the media. Lolita in the cinema and A Presença de Anita in the TV was disturbing in society and it projected the possibility of a syntaxes of desire. It can has a symbolic purpose or it can be a kind of social and cultural phenomenon, wich is an object of representation. Our purpose is to immersion/emerge in the Nimphs‟s body with adventure and its risks at the same time in wich we are crossing frontiers

Efeitos da tilápia do Nilo, Oreochromis niloticus, sobre a biomassa planctônica e a transparência da água ao longo de um gradiente de enriquecimento por nutrientes

The omnivorous filter-feeding fish, Nile tilapia (Oreochromis niloticus), can have negative effects on water quality enhancing the eutrophication process. These effects depend on the nutrient enrichment level in the water. We carried out a mesocosm experiment for five weeks in a tropical man-made lake in Brazil to test ifthe effects of tilapias depend on of the level of nutrient enrichment. The experiment lasted for 5 weeks and a factorial 2x5 experimental design was used where the presence and absence of tilapias were manipulated in combination to 5 different levels of nutrient load in a total of 10 treatments. A two way repeated measure ANOVA was performed to evaluate the effects of time (t), tilapia (F), nutrients (NP) and the interactions among these factors on: chlorophyll a, water transparency, total phosphorous, total nitrogen, N:P ratio, zooplankton biomass and phytoplankton biovolume. The tilapia effect was evident, but nutrient enrichment didn t have any effect on the variables analyzed. Tilapia decreased the water transparency, total zooplankton biomass, calanoid copepod biomass, nauplii copepod biomass and cladocerans biomass. On the other hand, tilapia had no effect on phytoplankton biovolume. This lack of effect on phytoplankton is probably due to tilapia grazing that may counteract the positive effect of tilapia on phytoplankton via trophic cascades and nutrient recycling. Hence, a reduction in tilapia stock would not be an effective way to reduce phytoplankton biomass and improve water quality

Respostas funcionais de diferentes tamanhos de Tilápia do Nilo; Oreochromis niloticus; predando zooplâncton

The Nile tilapia, Oreochromis niloticus, is an important omnivorous fish in the reservoirs of the semi-arid region of Brazil. Throughout its growth tilapia s feeding behavior changes from a visual predator of zooplankton to a filter-feeder, collecting suspended particulate matter, including planktonic organisms, through pumping. This feature results in different impacts of tilapia on plankton community as the fish grows. Aiming to quantify the functional response of different sizes of Nile tilapia on zooplankton experiments in microcosms scale in the laboratory and in mesocosm scale in the field were carried out. The data were fitted to four different models of functional response. The best fits were obtained for nonlinear models in laboratory experiments. While the experiments in mesocosms were the best settings for responses of type I (juvenile and adult tilapia) and type III (fry). The Manly's alpha index was used to evaluate the feeding selectivity of tilapia on the three main groups of the zooplankton in the experiments in mesocosms. The results show that: (i) rotifers were the preferred prey of fingerlings,(ii) copepods were rejected by fry and juvenile tilapia and (iii) adult fish fed non-selectively on copepods, cladocerans and rotifers. The functional response models obtained in this research can be applied to population models and help in modeling the dynamics of interactions between Nile tilapia and the planktonic communities in the reservoirs of the semi-arid

Apreciação ergonômica da atividade dos pescadores artesanais que utilizam jangadas na Praia de Ponta Negra-Natal/RN

The jangadeiros in the work activity are exposed to diverse and constant variability, which are extremely important to know in order to understand this activity and the risks they are exposed. The current study aims to analyze the work activity raftsmen of Ponta Negra beach in Natal, focusing on handling and quality of the fish sold by them to propose through the social construction recommendations for improving its product. To achieve this purpose was used a methodology inspired by the ergonomic work analysis using techniques observational and interactional. He was also made an assessment of fish sold by jangadeiros Ponta Negra, this evaluation was a sensory evaluation using the method "Torry Research" adapted by Vieira (2004) in order to assess the level of quality fish. In general it was observed that the fish originated from the fishing that rafts in Ponta Negra, have a good degree of freshness. But it was found that some ways of handling and storage can be improved

Extração supercrítica do óleo de linhaça: construção do extrator, estudo de parâmetros de processo, avaliação química e antioxidante do produto

The aim of the present study was to extract vegetable oil from brown linseed (Linum usitatissimum L.), determine fatty acid levels, the antioxidant capacity of the extracted oil and perform a rapid economic assessment of the SFE process in the manufacture of oil. The experiments were conducted in a test bench extractor capable of operating with carbon dioxide and co-solvents, obeying 23 factorial planning with central point in triplicate, and having process yield as response variable and pressure, temperature and percentage of cosolvent as independent variables. The yield (mass of extracted oil/mass of raw material used) ranged from 2.2% to 28.8%, with the best results obtained at 250 bar and 50ºC, using 5% (v/v) ethanol co-solvent. The influence of the variables on extraction kinetics and on the composition of the linseed oil obtained was investigated. The extraction kinetic curves obtained were based on different mathematical models available in the literature. The Martínez et al. (2003) model and the Simple Single Plate (SSP) model discussed by Gaspar et al. (2003) represented the experimental data with the lowest mean square errors (MSE). A manufacturing cost of US$17.85/kgoil was estimated for the production of linseed oil using TECANALYSIS software and the Rosa and Meireles method (2005). To establish comparisons with SFE, conventional extraction tests were conducted with a Soxhlet device using petroleum ether. These tests obtained mean yields of 35.2% for an extraction time of 5h. All the oil samples were sterilized and characterized in terms of their composition in fatty acids (FA) using gas chromatography. The main fatty acids detected were: palmitic (C16:0), stearic (C18:0), oleic (C18:1), linoleic (C18:2n-6) and α-linolenic (C18:3n-3). The FA contents obtained with Soxhlet dif ered from those obtained with SFE, with higher percentages of saturated and monounsaturated FA with the Soxhlet technique using petroleum ether. With respect to α-linolenic content (main component of linseed oil) in the samples, SFE performed better than Soxhlet extraction, obtaining percentages between 51.18% and 52.71%, whereas with Soxhlet extraction it was 47.84%. The antioxidant activity of the oil was assessed in the β-carotene/linoleic acid system. The percentages of inhibition of the oxidative process reached 22.11% for the SFE oil, but only 6.09% for commercial oil (cold pressing), suggesting that the SFE technique better preserves the phenolic compounds present in the seed, which are likely responsible for the antioxidant nature of the oil. In vitro tests with the sample displaying the best antioxidant response were conducted in rat liver homogenate to investigate the inhibition of spontaneous lipid peroxidation or autooxidation of biological tissue. Linseed oil proved to be more efficient than fish oil (used as standard) in decreasing lipid peroxidation in the liver tissue of Wistar rats, yielding similar results to those obtained with the use of BHT (synthetic antioxidant). Inhibitory capacity may be explained by the presence of phenolic compounds with antioxidant activity in the linseed oil. The results obtained indicate the need for more detailed studies, given the importance of linseed oil as one of the greatest sources of ω3 among vegetable oils

Memórias de rios e de lagos na construção romanesca: leitura de narrativas da Amazônia paraense

This study focalizes the memoirs of rivers and of lakes in the romantic construction starting from the romances Chove nos campos de Cachoeira (1941), Marajó (1947) and Três casas e um rio (1958), of writer Dalcídio Jurandir; of the book of memoirs Marajó, minha vida (1998), of writer Dita Acatauassu; of the story "A Feiticeira", published in the book Contos Amazônicos, written by Inglês de Sousa (1883); of the short story "O Peixe", published in O carro dos milagres, (1990), of writer Benedicto Monteiro; of the oral narratives Honorato: Cobra Grande , O encanto de Honorato and A Lenda da Cobra Norato , picked up by the project named The Imaginary in the Shape of Oral Narratives of Paraense Amazon (IFNOPAP) of the Federal University of Pará. In those speeches, the voices of the memory detach the multiple functions of rivers and lakes represented as space, atmosphere, scenery, route and route, thread and fabric, re-elaborated in the narrators' memoirs, characters and narrators/character of the fiction and in popular narratives

Dinâmica populacional e alimentar de Stegastes fuscus, (Osteichthyes:pomacentridae) em arrecifes da praia de Búzius, no Rio Grande do Norte

The damselfish, Stegastes fuscus Cuvier, 1830 (Osteichthyes: Perciformes: Pomacentridae), is abundant in the coastal reefs of Búzios Beach, Rio Grande do Norte, Brazil and they play an important role in the reef community ecology. The present study investigated the feeding strategy of this species considering the food habits and morfo-histology of the digestive tract. Influence of the environmental correlates such as temperature, rainfall and luminosity in the tidal rock pools were studied. The fish were captured on a monthly basis from September 2004 to August 2005, during which period 842 individuals of S. fuscus were captured, 125 males, 437 females and 280 individuals without sex identification. The sex ratio observed was 1 M : 3,5 F. The total body length of males varied from 3.6 to 11.3 cm, with a mean of 7.77 cm; that of females varied from 2.9 to 11.4 cm, with a mean of 7.85 cm, and that of sex grouped individuals varied from 2.9 to 11.4 cm, with a mean of 7.83. However, there was no difference between males and females in total body length. This species presented a positive alometric growth and the equations obtained for the relation between body mass and total body length were: Wt =0,0174Lt 3,1123 for males; Wt =0,0137Lt 3,2294 for females and Wt = 0,0148Lt 3.1928 for sex grouped individuals. The relation between total body length and standard length was L t = 1 ,3223Ls + 0,1527 for sex grouped individual s. February to August was associated to a long period of gonadal resting. The fish spawned during January and in September -October. The frequency of fish with empty stomachs occurred during August to December, whereas frequency of fish with food contents i n stomachs occurred during January to July. This species is considered as a preferential herbivore based on the volume of macroalgae in its diet composition. The morfo -histological aspects of S. fuscus confirm herbivory. Among the environmental factors con sidered only rainfall showed a correlation with the feeding habits of this species

Composição ictiofaunística e estratégias reprodutivas de quatro espécies de peixes nativos da Bacia Hidrográfica Piranhas - Assu, Rio Grande do Norte

This study focuses on the fish fauna composition and reproductive strategies of four native fish species in relation to environmental variables of the Piranhas-Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil. Fish and environmental data were collected monthly during the period September 2008 to February 2010, in the Marechal Dutra reservoir and River Acauã a tributary of Piranhas- Assu. The fish were measured, weighed and dissected, and the gonads were removed, weighed and examined macroscopically for identification and determination of gonad maturation stages. The results of this work generated seven articles. The first article is about the fish fauna composition of the Piranhas-Assu hydrographic basin, Rio Grande do Norte. The 602 fish samples captured were distributed in four orders (Characiformes, Perciformes, Siluriformes and Synbranchiformes), 11 families and 22 species, of which 17 are endemic to the Caatinga ecoregion. The order Characiformes was more representative followed by Perciformes, Siluriformes and Synbranchiformes. The second article is about the length-weight relationship and growth of seven native fish species Crenicichla menezesi, Cichlasoma orientale, Triportheus angulatus, Psectrogaster rhomboides, Pimelodella gracilis, Prochilodus brevis and Leporinus piau from a semiarid Brazilian reservoir. The third article is about the reproductive aspects of Crenicichla menezesi. Males were larger, heavier and with a slight predominance as compared to females. Four stages of gonadal development were characterized, being immature, maturing, mature and spent. The females reached sexual maturity earlier than males, with an average fecundity of 398 oocytes per batch. The spawning was partial with a long reproductive period. The fourth article deals with the reproductive strategy of Leporinus piau a neotropical freshwater fish in semi-arid region of Brazil. The population of L. piau (n = 211) showed a slight predominance of males (55%), with larger and heavier females. The males matured earlier than the females. This species presented total spawning, with an average fecundity of 55,000 mature oocytes. Rainfall and concentration of dissolved oxygen acted as influential factors during the spawning season. L. piau shows a seasonal reproductive strategy. The fifth article is related to the morphometric-meristic characteristics and reproductive aspects of freshwater sardine, Triportheus angulatus from River Acauã of the Caatinga biome. There was a predominance of larger females, reaching first maturation before males. There was total spawning during the rainy period of the region. The sixth article reports on the reproductive strategy of Psectrogaster rhomboides. The sex ratio was 1M: 1F, with negative allometric growth. Males reached sexual maturity earlier than females Females and males showed four stages of gonadal development and spawned during the rainy season. The fecundity was low and this species presented total spawning. The seventh article reports on the dynamics of territorial behavior of Crenicichla menezesi. Ten agonistic behaviors displayed by the males were observed: frontal and lateral threat, chasing, circular chasing, perpendicular, lateral and mouth attacks, escape, parallel positioning and stationary. The formation of four social groups was observed among males: without interaction; interaction with submission and escape; with frontal and lateral agonistic interactions. In social interactions between males and females, it was observed that the larger males interacted more among themselves and with the larger females. The large male established its territory and the two small males along with the small female were excluded from the other groups. These studies clarified the fish fauna composition and reproductive strategies of four native species Crenicichla menezesi, Leporinus piau, Triportheus angulatus and Psectrogaster rhomboides of the Piranhas- Assu hydrographic basin of the Caatinga biome, Rio Grande do Norte, Brazil.

Álcool e comportamento: efeitos na aprendizagem e memória

Excessive alcohol consumption is responsible for many harmful effects on individuals and society. Despite years of research, the mechanisms by which alcohol affects neurological functions and the exact causes of cognitive impairment related to long-term use are unknown. In this sense, this master study proposed to observe how different doses of alcohol affect the addiction response and the learning ability of two fish species: Betta splendens and Danio rerio, the latter a commonly model due to organizational and functional characteristics shared with mammals. For this, different concentrations of ethanol (0%, 0.1%, 0.25%, 1% and 1.5%) were used in acute, chronic and withdrawal treatments. We tested the fish in three experimental protocols: 1) alcohol addiction potential using conditioned place preference, 2) associative conditioning using light as unconditioned stimulus and food as conditioned stimulus and 3) spatial learning using a maze without cues. For the alcohol addiction potential, preference between two different places in a shuttle box was tested before and after alcohol exposure (chronic and acute). In this test, the animals intoxicated by 0.1% did not change behavior, while animals receiving 1% and 1.5% alcohol changed the initial preference to the side where they received alcohol For the associative conditioning, the results show that the groups undergoing low dose (0.1%), both in chronic and withdrawal treatment, learned the task faster than control; groups under 0.25 and 1% alcohol withdrawal learned the task after control; groups chronically intoxicated with these doses did not learn the task. For the spatial learning test, fish submitted to acute and chronic treatments decreased the time to exit the maze; there were significant differences in the animal s performance in a dose-dependent pattern. This difference was not observed for the withdrawal treatment. Given these results, we conclude that the effects of alcohol on learning are dependent on the dosage. Furthermore, low doses of alcohol seem to maximize animal performance on learning tasks and do not alter their seeking behavior, while higher doses induced addition and hinder learning

Hidrocarbonetos policíclicos aromáticos no meio ambiente: diferenciação de fontes em sedimentos e metabólitos em bile de peixes

Many studies on environmental ecosystems quality related to polycyclic aromatic hydrocarbons (PAH) have been carried out routinely due to their ubiquotus presence worldwide and to their potential toxicity after its biotransformation. PAH may be introduced into the environmet by natural and anthropogenic processes from direct runoff and discharges and indirect atmospheric deposition. Sources of naturally occurring PAHs include natural fires, natural oil seepage and recent biological or diagenetic processes. Anthropogenic sources of PAHs, acute or chronic, are combustion of organic matter (petroleum, coal, wood), waste and releases/spills of petroleum and derivatives (river runoff, sewage outfalls, maritime transport, pipelines). Besides the co-existence of multiples sources of PAH in the environmental samples, these compounds are subject to many processes that lead to geochemical fates (physical-chemical transformation, biodegradation and photo-oxidation), which leads to an alteration of their composition. All these facts make the identification of the hydrocarbons sources, if petrogenic, pyrolytic or natural, a challenge. One of the objectives of this study is to establish tools to identify the origin of hydrocarbons in environmental samples. PAH diagnostic ratios and PAH principal component analysis were tested on a critical area: Guanabara Bay sediments. Guanabara Bay is located in a complex urban area of Rio de Janeiro with a high anthropogenic influence, being an endpoint of chronic pollution from the Greater Rio and it was the scenario of an acute event of oil release in January 2000. It were quantified 38 compounds, parental and alkylated PAH, in 21 sediment samples collected in two surveys: 2000 and 2003. The PAH levels varied from 400 to 58439 ng g-1. Both tested techniques for origin identification of hydrocarbons have shown their applicability, being able to discriminate the PAH sources for the majority of the samples analysed. The bay sediments were separated into two big clusters: sediments with a clear pattern of petrogenic introduction of hydrocarbons (from intertidal area) and sediments with combustion characteristics (from subtidal region). Only a minority of the samples could not display a clear contribution of petrogenic or pyrolytic input. The diagnostic ratios that have exhibited high ability to distinguish combustion- and petroleum-derived PAH inputs for Guanabara Bay sediments were Phenanthrene+Anthracene/(Phenanthrene+Anthracene+C1Phenanthrene); Fluorantene/(Fluorantene+Pyrene); Σ (other 3-6 ring PAHs)/ Σ (5 alkylated PAH series). The PCA results prooved to be a useful tool for PAH source identification in the environment, corroborating the diagnostic indexes. In relation to the temporal evaluation carried out in this study, it was not verified significant changes on the class of predominant source of the samples. This result indicates that the hydrocarbons present in the Guanabara Bay sediments are mainly related to the long-term anthropogenic input and not directly related to acute events such as the oil spill of January 2000. This findings were similar to various international estuarine sites. Finally, this work had a complementary objective of evaluating the level of hydrocarbons exposure of the aquatic organisms of Guanabara Bay. It was a preliminary study in which a quantification of 12 individual biliar metabolites of PAH was performed in four demersal fish representing three different families. The analysed metabolites were 1-hydroxynaphtalene, 2-hidroxinaphtalene, 1hydroxyphenanthrene, 9-hydroxyphenanthrene, 2-hydroxyphenanthrene, 1hydroxypyrene, 3-hidroxibiphenil, 3- hydroxyphenanthrene, 1-hydroxychrysene, 9hydroxyfluorene, 4-hydroxyphenanthrene, 3-hydroxybenz(a)pyrene. The metabolites concentrations were found to be high, ranging from 13 to 177 µg g-1, however they were similar to worldwide regions under high anthropogenic input. Besides the metabolites established by the used protocol, it was possible to verified high concentrations of three other compounds not yet reported in the literature. They were related to pyrolytic PAH contribution to Guanabara Bay aquatic biota: 1-hydroxypyrine and 3-hydroxybenz(a)pyrine isomers