46 resultados para LITOPENAEUS SCHMITTI
Resumo:
The main specie of marine shrimp raised at Brazil and in the world is Litopenaeus vannamei, which had arrived in Brazil in the `80s. However, the entry of infectious myonecrosis virus (IMNV), causing the infectious myonecrosis disease in marine shrimps, brought economic losses to the national shrimp farming, with up to 70% of mortality in the shrimp production. In this way, the objective was to evaluate the survival of shrimps Litopenaeus vannamei infected with IMNV using the non parametric estimator of Kaplan-Meier and a model of frailty for grouped data. It were conducted three tests of viral challenges lasting 20 days each, at different periods of the year, keeping the parameters of pH, temperature, oxygen and ammonia monitored daily. It was evaluated 60 full-sib families of L. vannamei infected by IMNV in each viral challenge. The confirmation of the infection by IMNV was performed using the technique of PCR in real time through Sybr Green dye. Using the Kaplan-Meier estimator it was possible to detect significant differences (p <0.0001) between the survival curves of families and tanks and also in the joint analysis between viral challenges. It were estimated in each challenge, genetic parameters such as genetic value of family, it`s respective rate risk (frailty), and heritability in the logarithmic scale through the frailty model for grouped data. The heritability estimates were respectively 0.59; 0.36; and 0.59 in the viral challenges 1; 2; and 3, and it was also possible to identify families that have lower and higher rates of risk for the disease. These results can be used for selecting families more resistant to the IMNV infection and to include characteristic of disease resistance in L. vannamei into the genetic improvement programs
Resumo:
Shrimp farming in Brazil is a consolidated activity, having brought economical and social gains to several states with the largest production concentrated in the northeast. This fact is also reflected in higher feed intake, necessitating a more efficient feed management. Currently, management techniques already foresee food loss due to molting. In this sense, studies relating shrimp s digestive physiology, molting physiology and behavioral response of shrimp feed can optimize the feed management. Thus, our study aimed to evaluate the behavioral response of the marine shrimp L. vannamei (Crustacea: Penaeidae) in accordance with the stages of moulting cycle and feeding schedules based on higher or lower activity of proteolytic digestive enzymes; also, to investigate the influence of feeding schedule on hepatosomatic index and non-specific and specific protease activity (trypsin). Experiments were carried out at the Laboratory of Shrimp Behavioral Studies at UFRN in partnership with the Laboratory of Enzimology UFPE. Juveniles of L. vannamei weighting 5.25 g (+ 0.25 g) were kept in aquaria at a density of 33 shrimp m -2. In the first experiment, shrimp were fed in the light phase or in the dark phase for 8 days; in the ninth day, the animals were observed for 15 minutes every hour during the 12 hours of each phase of the photoperiod. We recorded the frequency of inactivity, exploration, food intake, burrowing, swimming and crawling behavior. At the end of the 12th observation session, the shrimp were sacrified and classified by the method of setogenesis in the molt cycle stages A, B, C, D0, D1, D2 or D3. We found that the shrimp in A stage show high levels of inactivity. Moreover, the frequency of food intake was very low. The shrimp in D3 stage also had low food intake and high inactivity associated with elevated frequencies of burrowing. In the second experiment, shrimp were kept in physiological acclimation to experimental conditions for 28 days, distributed in 12 treatments in the light phase and 12 treatments in the dark phase. In the end, the animals were sacrified and dissected to assess non-specific and specific protease activity (trypsin) activity. In general, these parameters did not vary among animals fed in the light phase and those fed in the dark phase. However, significant differences were found in the activity of specific and nonspecific proteases in relation to food treatment. In the light phase, the major proteolytic activities converged to 10 hours after the start of the light phase, while the lowest activities converged to 6 hours after the beginning of this phase. In the dark phase, the highest enzyme activity converged to 12 hours after the onset of phase, while the lowest activities converged to 3 hours after the onset of phase. In the third experiment, we sought to evaluate the behavioral responses of shrimp in relation to dietary treatments based on higher or lower activity of proteolytic enzymes, considering the results of the second experiment. The behavioral categories observed were the same as the ones in the first experiment, with observations of 30 minutes (15min before and 15min after food supply). We found variation in behavioral responses as a function of the treatments, with greater intake of food in shrimp fed during the period of greatest activity of proteolytic enzymes, in the light phase. Thus we see that periodic events associated with the shrimp s physiology interfere in their behavioral responses, revealing situations that are more adjustable to the provision of food, and consequently optimizing feeding management
Resumo:
The shrimp Litopenaeus vannamei has been grown in highly variable environments, especially in relation to salinity and water temperature. The adjustment to such conditions mainly involves changes in behavior, physiology, particularly in the immune response. This may consequently reduce the welfare of these animals. Despite the widespread farming of the species, little is known about their behavioral and physiological responses under stressful conditions. Thus, the objective of this study was to assess the influence of different salinities and temperatures in the behavior of the marine shrimp L. vannamei, and its relation to the total hemocytes count. In the laboratory, juvenile shrimp were kept in glass aquaria with a closed water recirculation system, continuous aeration and filtration, and under a 12:12 h light/dark cycle. Behavioral observations occurred 1, 4, 7 and 10 h after the start of each phase (light or dark). To assess the influence of salinity, shrimp were first acclimated and then observed at 2, 30 or 50 ppm salinity water, while temperatures tested were 18, 28 and 33 ° C. At the end of each experiment (30 days), shrimp hemolymph was collected for subsequent total hemocytes count (THC), a parameter used to assess stress. In general, feeding behavior was modified under lower salinity and temperature, with reduced values in feeding, exploration and digestive tract filling. Inactivity and burrowing were prevalent under extreme conditions water salinity and temperature, respectively: 2 and 50 ppm and 18 and 33 ° C; crawling was also less frequent under these conditions. In regards to light/dark cycle, shrimp were more active during the dark phase (crawling and swimming), while burrowing was higher during the light phase, regardless of salinity or temperature of the water. Inactivity behavior did not vary according to the light/dark cycle. Moreover, the total hemocytes count (THC) was reduced under 2 and 50 ppm salinity and 18 ° C temperature. Farming of L. vannamei under extremely low or high salinities and low temperatures is harmful. This suggests the species must be cultivated in salinities closer to those of the sea as well as at high temperatures, which seems to be ideal for a management focused on animal welfare, therefore, producing healthier shrimp
Resumo:
One of the factors that may interfere with the cultivation of Litopenaeus vannamei is the population density. This study aimed to assess the effect of density on growth, mortality, physical integrity and behavior of shrimp. The study was divided into two stages. At first, the shrimp were placed in tanks at densities of 50, 75 and 100 shrimp m-2. The animals were monitored in relation to the degree of proventricular filling, the stage of the molt cycle and physical integrity three times a week and in relation to the weight and length once a week. Mortality, growth and proventricular filling were not influenced by the density; frequency of records in specific stages of the molt cycle varied according to the density. The lower proportion of broken appendages and higher frequency of necrotic lesions occurred in lower density. The second stage of the research, conducted in aquaria, was divided into two parts. The first described social or feeding behavioral categories: slow displacement by contact, slow displacement by approximation, abrupt displacement by contact, abrupt displacement by approximation, reactivity, cannibalism, occupying the tray, get feed in the tray and get feed outside the tray. In the second part, these and other behavioral categories, described in the literature, were recorded in densities of 50, 75 and 100 shrimp m-2. Mortality was more frequent in higher density. The frequency of most behaviors mentioned above was very low, not differing between densities or being too low to determine differences between them. The behavioral profile of animals in different densities was, in general, very similar, with no difference in exploration, digging and cleaning between the densities. Even so, inactivity, feeding, crawling, burrowing, swimming, and proximity between animals were influenced by the density. These results suggest that some behaviors suffer greater interference from population density. However, the density may not have a broader influence on the animals when other factors, such as physico-chemical parameters of water and feed offering, are adequate
Resumo:
Carciniculture in Brazil occupies world-wide prominence due to shrimp culture, and the state of Rio Grande do Norte has presented the best results in the culture of the Litopenaeus vannamei in the last decade. This species has been shown to adapt easily to different environments and is between the five most cultivated penaeids of the world. The ponds are usually constructed in areas close to water courses and estuaries. Stock density and substrate ponds can pollute environment, causing losses in the growth and survival of the shrimps, being considered stress factors. Shrimps in inadequate densities and substrates can result reduced productivity of the farm; and favor diseases. So, it is important to verify how these variables influence the development of the animals in the culture farms. Our objective was to study the influence of the type of substrate and the stock density on the behavior and haemocyte count of the L. vannamei. Individually marked juvenile shrimps were kept in aquaria with 30 L of seawater and continuous aeration, in 12L-12D photoperiod. They were observed through Ad libitum and focal sampling instantaneous methods during thirty days, five times per week, six times per day (8:00 to 18:00) in windows of 15 minutes every two hours. The marking of carapace permitted quantifying molting and the feeding was supplied three times a day. Two experiments were carried out: the first one tested animals in the three different substrates (fine sand, smaller rocks-SPP and biggest rocks-SGR) with 33 shrimp/m2. In the second one, the animals were tested in three stock densities (26, 52 and 66 shrimp/m2) in fine sand substrate. At the end of experiment, biometry (first and second ones) and haemocyte count (second one) were made. The behavior of the L. vannamei seems to have been influenced by substrate and stocking density. In low granulometry of the substrate; the exploratory behavior became more frequent and inactivity of the shrimps was reduced. Burrowing was registered in sand substrate, specially in the initial period of the day. Cleaning was gradually higher along the day, presenting the biggest levels as the dark phase approached. The ingestion of feeding was more frequent in low density, and the animals were bigger and heavier at the end of the experiment. In the fine sand condition, the animals presented better growth, probably associated with the burrowing. The molting was equivalent in all types of substrate, but it was more frequent in high densities. Mortality of the shrimps was more frequent in high densities, and cannibalism and diseases were also registered in that condition. The clinical signals were similar to the ones of infectious mionecrosis (IMNV), generally associated with environment and physical stress. The haemocyte count was low for the hematologic standards of the penaeid, which we attributed for greater dilution of haemolymph in the postmolting phase. Smaller shrimps presented lower levels of haemocytes in relation to the bigger animals, count was also low in 26 shrimp/m2 density. The study demonstrates that stocking density and the granulometry of the substrate can affect the welfare, the health and the behavior of the L. vannamei. The sand substrate and low stocking density can be important tools in the management systems of shrimp production
Resumo:
The study aims to evaluate the performance and identify lesions of agonistic interactions of Macrobrachium rosenbergii in different densities cages (chapter 1); compare the growth performance of shrimp M. rosenbergii and Litopenaus vannamei cages (chatper 2); in addition the study aimed at identifying the knowledge and practices of a traditional community of farmers Bebida-Velha, in the city of Pureza / RN, practicing rural family and aquaculture, as well as tracing the community socioeconomic profile and evaluate the management that these farmers use in shrimp farming Macrobrachium rosenbergii (chapter 3). To perform the experiments (chapter 1 and 2) shrimp species L. vannamei and M. rosenbergii were weighed on a digital scale and transferred to cultures in cages. The cages had 1m³, with 5mm mesh between us and were closed on top with screen to avoid predators (birds, insects). The animals remained in adaptation for fifteen days before the start of data collection (each experiment). Both experiments lasted seventy days, totaling eighty-five days cultivation. During the cultures, animals were fed pelleted feed for shrimp at 10% of their biomass with 35% crude protein, offered in feed trays twice a day during the hours (7:00 am and 14:00 pm). The remnants in the tray were removed after 2h of permanence to calculate intake. To determine the performance parameters, some samples were taken every 10 days. The results of both experiments were analyzed using the STATISTIC 7.0 (2004). In Chapter 1 experiment were applied5 treatments were applied with 5 replications each: D5 - 5 animals/m2 ; D10 - 10 animals/m2 ; D15 - 15 animals/m2 ; D20 - 20 animals/m2 ; D25 - 25 animals/m2 . To this, were distributed 25 cages randomly in two masonry nurseries. The end of the experiment the lesions were verified and quantified. The chapter 2 experiment began when the shrimp reached the same age (eighty-four days) and was used the density of 25 shrimp / m2 with 4 repetitions. For the realization of chapter 3 were applied semi-structured interviews by direct approach of Bebida Velha of settlers practicing aquaculture activity, tilapia producers and community shrimp. Data were tabulated and analyzed according to the responses obtained by the participants. Therefore, the amount of damage increased with increasing stocking density. The density of 10 freshwater shrimp/m² showed the best conditions for a better performance in cages. It can be concluded that in cages, the cultivation of species of fresh water shrimp M. rosenbergii had better zootechnical indexes than the cultivation of marine shrimp species L. 9 vannamei. It was possible to verify that the activities of which the interviewees practice guarantee a good quality of life and income for them. We find that respondents have traditional and local knowledge, and also may be interested in the cultivation of the species M. rosenbergii.
Resumo:
This work was developed with the objective of proposing a simple, fast and versatile methodological routine using near-infrared spectroscopy (NIR) combined with multivariate analysis for the determination of ash content, moisture, protein and total lipids present in the gray shrimp (Litopenaeus vannamei ) which is conventionally performed gravimetrically after ashing at 550 ° C gravimetrically after drying at 105 ° C for the determination of moisture gravimetrically after a Soxhlet extraction using volumetric and after digestion and distillation Kjedhal respectively. Was first collected the spectra of 63 samples processed boiled shrimp Litopenaeus vannamei species. Then, the determinations by conventional standard methods were carried out. The spectra centered average underwent multiplicative scattering correction of light, smoothing Saviztky-Golay 15 points and first derivative, eliminated the noisy region, the working range was from 1100,36 to 2502,37 nm. Thus, the PLS models for predicting ash showed R 0,9471; 0,1017 and RMSEP RMSEC 0,1548; Moisture R was 0,9241; 2,5483 and RMSEP RMSEC 4,1979; R protein to 0,9201; 1,9391 and RMSEP RMSEC 2,7066; for lipids R 0,8801; 0,2827 and RMSEP RMSEC 0,2329 So that the results showed that the relative errors found between the reference method and the NIR were small and satisfactory. These results are an excellent indication that you can use the NIR to these analyzes, which is quite advantageous, since conventional techniques are time consuming, they spend a lot of reagents and involve a number of professionals, which requires a reasonable runtime while after the validation of the methodology execution using NIR reduces all this time to a few minutes, saving reagents, time and without waste generation, and that this is a non-destructive technique.
Resumo:
Inflammation is combined of a vascular and a cellular reaction, resulting in different cells and tissue responses, both the intravascular and extravascular environment. As the inflammatory process occurs, coagulation proteases, in particular thrombin (FIIa), are able to initiate various cellular responses in vascular biology and therefore is often observed activation of other biological systems, leading to complications during an event inflammatory, such as thrombosis and angiogenesis. Thus, antagonists molecules of these events are interesting models for the development of novel anti-inflammatory drugs. Thereby, it is worth stressing the glycosaminoglycans (GAGs), which are able to interact with several proteins involved in important biological processes, including inflammation and coagulation. Therefore, this study aimed to evaluate the anti-inflammatory, antithrombotic and anti-angiogenic potentials, as well anticoagulant of a dermatan sulfate-like GAG (DS) extracted from the Litopenaeus vannamei cephalotorax. The compound was obtained after proteolysis and purification by ion-exchange chromatography. After total digestion by DS-like compounds digesting lyases (chondroitinase ABC), the DS-like nature was revealed, and then called DSL. The shrimp compound showed reduced anticoagulant effect by the aPTT assay, but high anti-IIa activity, directly and through heparin cofactor II. On inflammation, the compound had a significant inhibitory effect with the reduction of proinflammatory cytokines. Potential Inhibitory were reported in the antithrombotic and anti-angiogenic assay, the latter being dose dependent. As for anti-hemostatic activity, the polysaccharides did not induced significant bleeding effect. Thus, the results shown by the shrimp DS-like compound indicate this glycosaminoglycan as a biotechnology target with prospects for the development of new multipotent drugs.
Resumo:
The aim of this study was to test the sediment preference of L. vannamei shrimp. It was observed shrimp visit frequency, swimming and burying behaviour at different sediment compositions for 24h. Juvenile (0.93 ± 0.29g) and sub-adult shrimps (10.0 ± 1.18g) were obtained from the aquaculture station at Universidade Federal Rural do Semi-Árido UFERSA, and held in a plastic tank (water volume 500 L) supplied with aerated water and kept at constant temperature, pH, and salinity. Shrimp was fed by commercial shrimp dry food. The experimental substrates were composed by A: medium sand + thick sand + very thick sand + gravel; B: very fine sand + fine sand; and C: silt + clay. Thus, six different substrate combinations were tested: A, B, C, A+B, A+C, B+C. To test preference, it was used a cylindrical tank (40 l) divided into six differently substrate compartments. A single shrimp was introduced each tank and the frequency at which this shrimp visited each compartment was recorded over a 24h study period. It was tested 54 shrimp (18 sub-adult males, 18 subadult females and 18 juveniles). For each trial, sediment and water were changed to avoid pheromones and residues influence. Shrimp were weighted and sub-adults were divided by sex: males present petasma and females present thelycum. Data were collected on the experimental day at 19:30; 20:30; 00:30; 1:30; 05:30; 06:30; 13:30 and 14:30 h. At each time point, shrimp were observed for 20-min periods, in which we noted down which compartment the shrimp was occupying at 2-min intervals. Thus, for each period we had eleven observations (88 observations per day). For observations at night, it was used dim red light that did not affect shrimp behaviour. At each 20-min period, it was observed visit frequency in each substrate, if shrimp was burred or not or if it was swimming. There was not significant difference between light and dark burry activity for females. Swimming activity was significantly higher at night, mainly at 00:30 and 01:30 h. All L. vannamei shrimp showed preference for sediment B. This animal presents cyclic activity, spends the day light period buried and swims at night
Resumo:
The expansion of shrimp farming has caused a series of environmental impacts, often as a result of lack of planning and adequate management. Organic aquaculture has emerged as an alternative to conventional shrimp farming, and differently, aims at the economical, ecological and farming potential of other organisms, such as fishes, oysters and seaweeds. The present study aimed at evaluating the biological diversity and abundance of the ichthyofauna associated to Litopenaeus vannamei organic culture at PRIMAR farm (Rio Grande do Norte, Brazil). The sampling period consisted of four culture cycles (1, 2, 3, and 4) accomplished in four grow-out ponds (V1, V7, V2, and V4) in 2005. The first two culture cycles were carried out during the rainy season, and the last two cycles, during the dry season. Environmental (temperature, salinity, transparency, and rainfall), biodiversity (diversity and uniformity and abundance indexes) of the ichthyofauna, and shrimp productivity data were collected throughout these four culture cycles. The results obtained for the environmental variables showed that both salinity and transparency oscillated in a significant way (p < 0.001) between culture cycles. In relation to the abundance of the ichthyofauna, fifty four species associated to the organic culture of Litopenaeus vannamei were collected and identified at PRIMAR. For the biodiversity criterion, larger species richness (S = 46) and uniformity (E = 0.59 ± 0.16) were observed during cycles 3 and 4 than in cycles 1 and 2 (S = 41 and E = 0.15 ± 0.12). A positive and significant correlation was obtained for the transparency with diversity and uniformity of fish species between cycles 1 and 2 (wet season) and cycles 3 and 4 (dry season) (p < 0.017 - Shannon Index; p < 0.008 - Pielou Index, respectively). A correlation could not be established between shrimp productivity and fish biomass. However, fish biomass decreased from cycles 1 and 2 to cycles 3 and 4, concomitant with an increase in shrimp productivity, most probably due to a higher (from 58.0% to 71.0%) shrimp survival. Regarding the culture potential of the ichthyofauna, three species (Mugil curema, Mugil liza and Chaetodipterus faber) were identified as potential farming alternatives, either singly or in consortium with Litopenaeus vannamei. A fourth species (Centropomus undecimalis) was indicated as an alternative for single culture or in consortium with other fish species. In conclusion, the large diversity of estuarine fishes associated to Litopenaeus vannamei farming observed at PRIMAR clearly indicated the ecological feasibility for organic aquaculture in northeastern Brazil
Resumo:
The occurrence of bioactive compounds in marine organisms comes awaking the interest of the pharmaceutical industry. Heparin, a sulfated polysaccharide which presence was already identified in several marine invertebrates, is very attractive due its remarkable functional versatility. Besides to intervene in blood coagulation, this molecule has a great anti-inflammatory potential. However, its strong anticoagulant activity difficult the clinical exploitation of its anti-inflammatory properties. Thus, the aims of this work were to evaluate the effect of a heparin-like compound (heparinoid), isolated from the cephalotorax of the Litopenaeus vannamei shrimp, on the inflammatory response, hemostasia and synthesis of antithrombotic heparan sulfate by endothelial cells, besides studying some aspects concerning its structure. The purified heparinoid was structurally characterized following an analytical boarding, involving electrophoresis and chromatography. The structural analysis have shown that this compound possess a high content of glucuronic acid residues and disulfated disaccharide units. In contrast to mammalian heparin, the heparinoid was incapable to stimulate the synthesis of heparan sulfate by endothelial cells in the tested concentrations, beyond to show reduced anticoagulant activity and hemorrhagic effect. In a model of acute inflammation, the compound isolated from the shrimp reduced more than 50% of the cellular infiltration. Besides reduce the activity of MMP-9 and proMMP-2 of the peritoneal lavage of inflamed animals, the heparinoid also reduced the activity of MMP-9 secreted by activated human leukocytes. These results demonstrate the potential of heparinoid from L. vannamei to intervene in the inflammatory response. For possessing reduced anticoagulant activity and hemorrhagic effect, this compound can serve as a structural model to direct the development of more specific therapeutical agents to the treatment of inflammatory diseases
Resumo:
Sulfated Polysaccharides with unique chemical structures and important biological activities has been found in a diversity of sea invertebrates. For that, to exist a huger interest on the biotechnology field in the research theses sulfated compounds isolated from sea organisms. Despite the privileged brazilian position for these compounds attainment, there are still a few scientific informations about the isolated substances and their biological activities. A head the displayed, the present work has for objectives, to evaluate the pharmacological properties of the glycosaminoglycans isolated from the sea shrimp Litopenaeus schimitti on homeostasis, blood coagulation, leukocytes migration and platelet/leukocyte adhesion. For this, yhe glycosaminoglycans were extracted from crustacean tissues by proteolysis, fractionation with acetone and later submitted to pharmacological assays. The crustacean tissues showed compounds heparin-like, with anticoagulant activity of 45 IU/mg and 90 IU/mg, respectively. These molecules showed low residual hemorrhagic effects in the tested concentration (100 µg/mL), when compared to unfractionated commercial heparin (UFH). Another dermatan sulfate-like compound, predominately constituted for disulfated disaccharides, was isolated from crustacean abdomen. This compound showed an efficient effect on leukocytes migration inhibition, in the concentration of 15 µg/mL, reducing the cellular infiltration in 65% when compared to the controlled animals. In this same concentration, the DS reduced in 60% the protein concentration of the peritoneal exudates. In the concentration, this compound of 0.5 mg/mL, it was capable to reduce in 40% platelet/leukocytes adhesion. Our data demonstrate that these sulfated polysaccharides isolated from the shrimp L. schimitti will can be used as bioactive compounds, appearing as active principles for pharmacological development, anticoagulants and inflammatory response regulators
Resumo:
In recent years the heparin has been the subject of several studies that aim to expand its use as a therapeutic agent, due to its ability to modulate the activity of various proteins that play important roles in the regulation of pathophysiological processes. In several experiments and preclinical trials, heparin has demonstrated an anti-inflammatory role. However, its clinical use is limited, due to its strong anticoagulant activity and hemorrhagic complications. For this reason, considerable efforts have been employed in discovery of heparin analogous (heparinoid) with reduced side effects, that retain the anti-inflammatory properties of heparin. In this context, a heparinoid obtained from the head of Litopenaeus vannamei shrimp, which presents a structural similarity to heparin, showed, in previous studies, anti-inflammatory activity in a model of acute peritonitis with reduced anticoagulant effect in vitro and low hemorrhagic activity. Thus, the present work had as objective to evaluate the effect the heparinoid of the cephalothorax of gray shrimp on the acute inflammatory response in different times (3 or 6 hours after the induction of inflammatory stimulus), using the model of acute peritonitis induced in mice. It was also analyzed the HL effect over the activity of elastase, an enzyme involved in leukocyte recruitment. Furthermore to check if the different doses of heparin and heparinoid change the hemostatic balance in vivo, was assessed the effect of these compounds on the plasma clotting time in animals submitted to inflammation. The results show that in 3 hours, all doses of heparinoid were able to prevent efficiently in the acute inflammatory process without any anticoagulant effects, unlike the extrapolation dose of heparin, which has induced a large hemorrhage due its high anticoagulant activity. However, 6 hours after induction of inflammation, only the dosages of 0.1 and 1.0 μg/Kg of heparin and 1.0 μg/Kg of heparinoid kept anti-migratory effect, without changing of the hemostatic balance. These results indicate that the anti-migratory effect of theses compounds depends on the dosage and time of inflammatory stimulus. The HL and heparin were also able to inhibit the activity of the enzyme elastase. The discovery of this bioactive compound in the cephalothorax of shrimps can arouse great interest in biotechnology, since this compound could be useful as a structural model interesting for the development of new therapeutic agents for peritonitis
Resumo:
without practical results so far. Protocols used in biotechnological cultured aquatic organisms aimed at increasing growth rates and disease resistance, have been studied and perfected. Among the available techniques, the application of chromosomal manipulation, although still nascent, is presented as a tool aimed at mitigating ecological and economical issues in shrimp farming. The polyploidization artificial method already employed in fish and shellfish, has been widely researched for use in farmed shrimp. Some limitations of this method of expansion in shrimp refer to a better knowledge of cytogenetic aspects, the level of sexual dimorphism and performance in growing conditions. To contribute on some of these issues, the present study aimed to characterize cytogenetic species Litopenaeus vannamei (Decapoda) and Artemia franciscana (Anostraca), analyze the effectiveness of methods for detection of ploidy, through the use of flow cytometry in processes of induction polyploidy cold thermal shock at different stages of development of newly fertilized eggs. Additionally, aimed also the qualitative and quantitative comparison of larval development between diploid and polyploid organisms, besides the identification of sexual dimorphism in L. vannamei, through geometric morphometrics. The results provide information relevant to the improvement and widespread use of biotechnological methods applied toward national productivity in shrimp farming
Resumo:
The shrimp farming industry is the most profitable area of the aquaculture at Rio Grande do Norte (RN) state, which is one of the largest producers in Brazil. However the infections that affect the shrimp cause major economic losses. The infection is a result of the interaction between the shrimp, the environment and pathogen. The change of these factors may lead to a condition of stress and susceptibility to opportunistic infections. One of these infections caused by Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) is widely distributed in several countries and affects a wide range of hosts. To optimize conditions for production of Litopenaeus vannamei shrimp, the more species cultivated in Brazil, it is necessary to understand the effects of environmental factors in the susceptibility of this species to infections. The aim of this study was to determine the IHHNV prevalence and to investigate the influence of environmental factors as salinity, temperature, stocking density, dissolved oxygen and rainfall in the IHHNV incidence in L. vannamei grown in farms, in the RN state. To determine the IHHNV prevalence were used 1089 samples of L. vannamei collected in seven farms. To perform the study about the influence of environmental factors, 525 samples of L. vannamei shrimp were collected in eight farms located in regions of low (0-1 ), medium (21-30 ) and high (38-57 ) salinity, using extensive (≤15 shrimp/m2 ), semi-intensive (18-33 shrimp/m2) or intensive (>36 shrimp/m2) stocking density systems. The IHHNV infection was determined in pleopod and hemolymph using the polymerase chain reaction (PCR). The environmental factors were recorded during the collection of animals, using a refractometer to measure the salinity and a multi-parameter meter to measure the temperature and concentration of dissolved oxygen in the water. The IHHNV prevalence in RN was 43% (468 infected shrimp out of 1089), varying on different farms. On the seven farms studied, IHHNV prevalence ranged from 18.6% to 54.8%. The infection rates in the shrimp cultured in low, medium and high salinity were respectively 43.10% (125/290), 31.2% (15/48) and 24.6% (46/187) and was significantly higher in shrimp grown in low salinity (P<0.001). The infection rates in ponds of extensive, semi-intensive and intensive systems were respectively, 28.7%, 28.28% and 47.84%, and was significantly higher in high stocking densities (P<0.001). This study indicated a high IHHNV prevalence and a significant effect of salinity and stocking density, but not of the temperature, rainfall and dissolved oxygen on the IHHNV infection rate in the L. vannamei shrimp cultured in the northeastern Brazil