Janessa Sampaio de Abreu

Stress responses of the endemic freshwater cururu stingray (Potamotrygon cf. histrix) during transportation in the Amazon region of the Rio Negro.

Potamotrygon cf. histrix (cururu stingray) are endemic freshwater stingrays from the middle region of the Rio Negro in the Brazilian Amazon basin and are exported worldwide as ornamentals caught by artisanal fishermen. The transport process from capture to final destination is long and stressful. This study quantified stress related changes in corticosterone, blood and water samples (baseline, pre-transport, 3h, 12h and 24h) analyzed during a transport experiment which tested two water additives (tetracycline and the probiotic Efinol). There was a significant stepwise increase in corticosterone levels in stingrays over transport time in combination with osmoregulatory disturbances suggesting a stress related role of this corticosteroid. There were significant increases in water conductivity, Na(+) and K(+) losses and ammonia excretion. Blood parameters such as glucose, hematocrit, red blood count and urea did not change significantly during the experiment. Glucose levels did not increase significantly during transport and this may be due to the fact that other elasmobranchs have been shown to rely more on ketone bodies for energy rather than glucose and produce ammonia as their main nitrogenous waste. The mineralocorticoid action of this hormone has been shown in elasmobranchs and most likely plays a role in osmotic homeostasis. The use of probiotic and especially antibiotic should be avoided since no beneficial effects were observed.

Stress responses of juvenile matrinxã (Brycon amazonicus) after transport in a closed system under different loading densities

Optimum loading density for the transport of matrinxa juveniles was investigated in a closed system with plastic bags. Transport was conducted for 4 h with fish (23.5± 0.4g and 11.6 (0.08cm) starved for 24h at loading densities of 83g L-1 (D1), 125g L-1 (D2), 168g L-1 (D3) and 206g L-1 (D4). Fish were sampled before transport (BT), after transport (AT) and 24h AT. The water quality was monitored before capturing fish in depuration tanks, after transport in plastic bags and in recovery tanks. Water oxygen decreased to values below 4mg L-1 in D2, D3 and D4, temperature was around 32°C, pH 6.5-6.78, total ammonia 1.09-1.7mg L-1, un-ionized ammonia 3.58-9.33x103mg L-1 and alkalinity 134-165mg CaCO3 L-1. Blood cortisol and glucose concentrations increased in fish of all densities AT and recovered the BT levels 24h after arrival. Osmolality did not change AT but increased 24h AT in fish of all densities whereas plasma chloride decreased inversely to the loading densities after the procedure. Hematocrit decreased 24h AT in fish of all densities but no differences were verified in the number of erythrocytes. No mortality was registered in any treatment during the next week after transport. Matrinxa demonstrated to be a crowding tolerant-species in transport operations besides tolerating low levels of oxygen in the water.

Bem-estar e taxa de hematomas de bovinos transportados em diferentes distâncias e modelos de carroceria no estado do Mato Grosso - Brasil

The welfare, bruising incidence of 3,415 Nelore cattle transported on different types of truck (simple truck, trailer truck, and double-deck trailer) and transport distance was evaluated.Animals transported by double deck and trailer showed a higher incidence of falls (77.52a; 75.31a) compared to simple trucks (49.09b). Higher incidence of slips (95.78a), vocalizations (82.9a), use of electrical probes (96.06a) and crashing into fixed objects (88.74a) were also observed in animals transported by double deck in comparison to the trailer and simple truck. In the second experiment, 120 Nelore beef cattle were transported using the same trucks in the same slaughterhouse but in two different transport distance (over 180km and below 130km). Was observed a higher incidence of bruising on carcasses of cattle transported by double deck truck in both distances (1.09a, 1.02b) in comparison to the others treatments, as well as greater extent of lesions (1.81a, 1.65b). Was used the nonparametric Kruskal-Wallis test at 5% significance in a randomized design.

Características histomorfométricas do intestino de juvenis de tambaqui após uso de probiótico na dieta e durante transporte

This study evaluated the histomorphometric characteristics of tambaqui intestinal mucous after using Bacillus spp based probiotics, incorporated in feed and dissolved in water during transport. It was used a completely randomized design, with three treatments and seven replications, and a control treatment (fish fed commercial feed without probiotic) was compared with two other treatments involving the use of commercial probiotic incorporated in the feed or in the transport water. A total of 510 juvenile tambaqui (average weight and total length 83.26±28.14g and 17.39±1.90cm, respectively) was distributed in three cement tanks. During 60 days, fish of two tanks were fed with commercial feed and fish of the third tank received commercial feed supplemented with probiotic. After this period, the fish from each tank were divided into plastic bags and transported for 4 hours according to the following treatments: T1 = feeding with commercial feed (control); T2 = feeding with commercial feed and probiotic dissolved in the water during transport (20mg/L); T3 = feeding with commercial feed supplemented with probiotic (1.0g/kg feed). Before transport (basaline), 24 and 96 hours after transport, eight fish of each treatment were submitted to euthanasia and the intestine was removed for weighing and length measuring to establish the relation between length/gut ratio. Then, the anterior and posterior portions of the intestine were collected for evaluation of morphological and histological characteristics of intestinal mucous. The use of probiotic during transport did not affect the intestine weight of tambaqui. Regardless of the treatment, the intestine length increased as the fish increased in size. The supplementation with probiotics (Bacillus spp.) had no effect on height and length villus of tambaqui’s intestine during transport challenge.

Effect of beta 1,3 glucan in stress responses of the pencilfish (Nannostomus trifasciatus) during transport within the rio Negro basin

We investigated the use of beta 1,3 glucan as an imunostimulant during a transport experiment to determine the effects upon the stress response of the pencilfish (Nannostomus trifasciatus). Pencilfish were fed for seven days with different concentrations of beta 1,3 glucan: 0.0% (control); 0.01%; 0.1% and 0.5% of beta 1,3 glucan per kg of feed-1. Fish were then transported for 24 hours by boat from Barcelos to Manaus. The highest dose of beta 1,3 glucan in the food increased Na+influx after 12 hours of transport and 0.1 and 0.5% beta 1,3 glucan maintained the flux of both ions close to zero at 24 hours. All doses of beta 1,3 glucan reduced K+ loss significantly in the beginning of the transport, but after 12 to 24 hours did not. No significant differences in whole body cortisol or survival were observed. Our results indicate that pencilfish had ionic alterations during transport from Barcelos to Manaus. The lack of significant differences in whole body cortisol and survival rate in addition to the maintenance of Na+ and K+ balance during transport reinforce the positive effects of beta 1,3 glucan immunostimulant on fish homeostasis. Therefore, we recommend its addition to food prior to transport.

Economic viability of the piauçu Leporinus macrocephalus (Garavello & Britski, 1988) production

Brazilian fish farms presented an accelerated development during the early 90s, mainly because of the increase in fee-fishing operations. To meet the demand of this market, fish production and supply became excessive and, as a consequence, the number of fee-fishing operations, farmers and the final selling price, decreased. This study analyzes the technical aspects, production cost, profitability and economic viability of the production of piaucu (L. macrocephalus) in ponds, based on information from a rural property. Feeding and fingerling costs amount to approximately 47.1% of the total production cost, representing together with the final selling price the most important factor affecting profitability. The payback period was 8.3 years, the liquid present value US

Ovopel® and carp pituitary extract for induction of reproduction in Colossoma macropomum females

291.07, the internal return margin 9%, and the income-outcome ratio was 1.01, which represents an unattractive investment as a projection based on current conditions. The improvement in productive efficiency enhances the economic valuation index, and that the relative magnitude of cost and income are the most important points for the economic viability of the studied farm.

Stress in pacu exposed to ammonia in water

The aim of this study was to evaluate the efficiency of the hormonal inducers Ovopel® and carp pituitary extract (CPE) for induction of reproduction in Colossoma macropomum females. The treatments were CPE at the dose of 5.5 mg/kg divided into two applications (10%; and 90% after 12 h) and Ovopel® at doses of 0.2 and 0.4 pellet/kg body weight in a single application. Eight replicates were used in each of the three treatments, totaling 24 experimental units. The females spawned when treated with the 0.2 pellet of Ovopel® (100.0%), 0.4 pellet of Ovopel® (62.5%), and CPE (87.5%), but there were no significant differences among the treatment groups in spawning rate. When there was treatment with Ovopel® spawning occurred with greater (P < 0.05) degree-hours (average water temperature × number of hours until spawning; 0.2 pellet: 417.7; 0.4 pellet: 412.3) in relation to the CPE treatment (268.9). The total oocyte weight was similar when there was treatment with Ovopel® (0.2 pellet: 832.3 g; 0.4 pellet: 798.9 g) and CPE (688.3 g). By contrast, the production index was greater (P < 0.05) with the Ovopel® treatments (0.2 pellet: 8.8%; 0.4 pellet: 9.0%) as compared with CPE (6.7%). Fertility and hatching rates were similar among the treatment groups. Ovopel® and CPE are efficient in induction of reproduction in C. macropomum females. Of the two Ovopel® treatments assessed in this study, the dose of 0.2 pellet/kg body weight is sufficient for effective induction of reproductive processes.

Routine exposure to biometric procedures in fish farming reveals differences in stress response in tambaqui and hybrid tambatinga

The present study evaluated stress indicators in pacu exposed to ammonia in water under the following conditions: without NH4Cl (0.00 g/L); with 0.0078 g NH4Cl/L; and with 0.078 g NH4Cl/L (pH 8.3 and 27 oC). After the salt dilution the water flow was interrupted and reestablished in 24 hours. Sampling occurred prior to the addition of NH4Cl (control) and after 12, 24 and 48 hours. Glycaemia increased only in fish with the highest salt concentration when compared with group control, regardless of time, and at 24 hours, regardless of treatment. Plasma ammonia, highest in fish exposed to the highest NH4Cl concentration, decreased progressively up to 48 hours. Plasma chloride only decreased in fish not exposed to salt when compared with control and osmolality increased after 24 hours. Hematocrit (Ht), number and volume of erythrocytes and hemoglobin did not change when NH4Cl was added; Ht decrease was reported after 12 hours, but it was not followed by the other blood parameters. The results show tolerance of the pacu to ammonia in the environment.

Performance of hybrid catfish subjected to different protein levels

The physiological stress responses of tambaqui and hybrid tambatinga were evaluated after subjecting the fish to routine practices in a breeding system such as periodic biometric procedures. For 270 days of culture, the fish underwent monthly biometric measurements, and at the end of the period, blood was collected at six sampling times (before, immediately after and 2, 24, 48 and 72 h after biometric measurements) for the evaluation of physiological indicators of stress. Tambatinga are more susceptible to stress because they presented higher levels of cortisol and glucose in the bloodstream after handling and took longer to recover their basal physiological state for these parameters. However, the low cortisol levels observed in both species suggest that the fish were familiar with biometric procedures, resulting in a less intense response. Handling led to an increase in the cellular volume of erythrocytes in tambaqui, resulting in a change in hematocrit and a decrease in hemoglobin concentration. Hypochloremia was found in both species only 72 h after handling. Biometric procedures promote hormonal, hematological and hydroelectrolytic changes in the tambaqui and hybrid tambatinga, but when routinely adopted, at regular intervals, they elicit stress responses of lower magnitude.The physiological stress responses of tambaqui and hybrid tambatinga were evaluated after subjecting the fish to routine practices in a breeding system such as periodic biometric procedures. For 270 days of culture, the fish underwent monthly biometric measurements, and, at the end of the period, blood was collected at six sampling times (before, immediately after, and 2, 24, 48 and 72 h after biometric measurements) for the evaluation of physiological indicators of stress. Tambatinga is more susceptible to stress because it presented higher levels of cortisol and glucose in the bloodstream after handling and took longer to recover its basal physiological state for these parameters. However, the low cortisol levels observed in both species suggest that the fish were familiar with biometric procedures, resulting in a less intense response. Handling led to an increase in the cellular volume of erythrocytes in tambaqui, resulting in a change in hematocrit and a decrease in hemoglobin concentration. Hypochloremia was found in both species only 72 h after handling. Biometric procedures promote hormonal, hematological and hydroelectrolytic changes in the tambaqui and hybrid tambatinga, but when routinely adopted, at regular intervals, they elicit stress responses of lower magnitude.