RESUMO
This study investigated the in vitro antimicrobial and anthelmintic effect of copper nanoparticles (CuNPs) against the bacterium Aeromonas hydrophila, the monogeneans Dactylogyrus minutus, Dactylogyrus extensus, Gyrodactylus cyprini, and the cestode Schyzocotyle acheilognathi, as well as their toxicity to Cyprinus carpio Koi. In the antimicrobial in vitro test, the inhibition zone method and minimum inhibitory concentration (MIC) were performed. In order to determine the time and efficacy of monogenean parasite mortality, the parasites were exposed to CuNP concentrations of 20, 50, 100, 150, 200, and 300 mg L-1, and a control group with tank water and one with copper sulphate pentahydrate (CuSO4.5H2O) at a concentration of 0.3 mg L-1, performed in triplicate. The parasites were observed every 10 min for 300 min, and mortality was recorded. For the cestodes, parasites were immersed in CuNP concentrations of 50, 100, 150, and 300 mg L-1. At the end of the in vitro tests, the anthelmintic efficacy of each treatment was calculated. To assess the tolerance and toxicity in fish, they were exposed to CuNP concentrations of 0.6, 1.25, 2.5, 5, 10, 20, and 50 mg L-1 for 12 h. The MIC demonstrated that CuNPs effectively inhibited the growth of A. hydrophila up to a dilution of 12,500 mg L-1 and showed an inhibition zone of 14.0 ± 1.6 mm for CuNPs. The results of anthelmintic activity showed a dose-dependent effect of concentration for both groups of parasites, with the most effective concentration being 300 mg L-1 in 120 min. In the toxicity test, the carps showed tolerance to lower concentrations. The study indicated that CuNPs were effective against the studied pathogens. However, it proved to be toxic to fish at high concentrations. The use of low concentrations is recommended still requires further investigation.
RESUMO
This study investigated the in vitro and in vivo efficacy of trichlorfon against Dawestrema cycloancistrium, as well as its physiological effects on arapaima. Naturally parasitized arapaima gill arches were exposed in vitro to 100, 250, 500 and 750 mg/L of trichlorfon and a control group (only distilled water), in triplicate. Parasites were monitored, and mortality was used to determine the median effective concentration (EC50 ). The 750 mg/L concentration demonstrated 100% in vitro efficacy against D. cycloancistrium after 60 min, while the intermediate (500 mg/L) and the lowest (100 and 250 mg/L) tested concentrations were completely efficient after 90 and 130 min, respectively. The EC50-1h of trichlorfon for D. cycloancistrium was determined at 171.73 mg/L. Parasitized arapaima juveniles were exposed to a control group and 150 mg/L of trichlorfon in triplicate. Fish were exposed to two therapeutic baths for 60 min with 24-h intervals between treatments. Therapeutic baths with 150 mg/L of trichlorfon were 92.99% effective against D. cycloancistrium and did not bring about haematological alterations (erythrogram, white blood cell count, thrombogram, plasma glucose and total proteins). Therefore, 150 mg/L of trichlorfon can be used in therapeutic baths to control and treat D. cycloancistrium infestations with no physiological impairments for arapaima.
Assuntos
Doenças dos Peixes , Triclorfon , Animais , Peixes , BrânquiasRESUMO
Acanthocephalosis in tambaqui Colossoma macropomum culture is a limiting factor for the production of the species, being the most recurrent, which makes it necessary to develop strategies to control parasitosis even in the early stages of parasite development. This study aimed to elucidate the morphological characteristics of eggs of the acanthocephalan Neoechinorhynchus buttnerae and the ovicidal effect of the essential oils of Lippia alba, Lippia sidoides, and Lippia gracilis. The parasites were collected from hosts naturally infected with N. buttnerae, and the eggs obtained from the female 'parasites' abdominal cavity were added to 12-well plates containing the essential oils at different dilutions. After the eggs (N = 300) were separated and measured (length and width) with the aid of an optical microscope coupled to a digital program, the viability of the treated eggs was monitored 24 h after treatments, L. gracilis essential oil was 100% effective at the highest concentration, whereas L. sidoides essential oil showed over 50% efficacy at 2 mg/ml, reaching 100% efficacy at all higher concentrations. Lippia. alba essential oil did not show satisfactory efficacy in preventing N. buttnerae egg hatching.
Assuntos
Acantocéfalos , Caraciformes , Doenças dos Peixes , Lippia , Óleos Voláteis , Animais , Caraciformes/parasitologia , Feminino , Doenças dos Peixes/parasitologia , Óleos Voláteis/farmacologia , Óleos de Plantas/farmacologiaRESUMO
In Brazil, studies evaluating the concentration of trace metals in fish farms are scarce. Therefore, studies investigating the presence and levels of these metals in aquatic biota, particularly in fish tissues, are crucial for developing appropriate strategies to mitigate the impact of possible toxic metals. Herein, we investigated the levels of trace metals (Cr, Mn, Co, Ni, Cu, Zn, Al, Ag, Cd, Pb, Fe, Na, Mg, Ca, K, and Ba) in water, feed, and sediment, as well as the bioconcentration and bioaccumulation factors in tambaqui muscles (Colossoma macropomum). For this purpose, eight commercial fish farms, which are also engaged in other agricultural activities, were selected. Fe, Zn, Mg, and Cr concentration in tambaqui muscles exceeded the limits set by the Brazilian regulations for daily consumption by adults. Mn, Zn, Al, Pb, Fe, Na, Cu, Co, Ag, Cd, and Ba levels were substantially higher in the liver tissue of tambaquis than those in the muscle tissue. The most prevalent metals found in the feed were Ca, K, Na, Mg, and Fe. However, the levels of Cr and Cd in the sediment, as well as Pb, Mn, Cu, and Fe in the water, exceeded the maximum limits allowed by the Brazilian legislation. The highest bioconcentration factors were observed for the metals, Na, Zn, and K, with concentrations up to 4.74, 12.61, and 72.08 times, respectively, higher in tambaqui muscle compared to those in water. The bioaccumulation factors for Ca, Zn, Mg, Na, and K were 2.90, 6.96, 21.21, 212.33, and 492.02 times, respectively, higher in the muscle tissue than those in the sediment values in fishponds across all fish farms. Therefore, our findings suggest that tambaquis have a remarkable ability to bioaccumulate trace metals, particularly the essential ones, and can be categorized as a bioindicator species for environmental quality. Furthermore, we observed that, although water exhibits the highest prevalence and diversity of elements above the values recommended by the Brazilian legislation, sediment is the primary source of trace metal contamination for tambaquis.
Assuntos
Caraciformes , Metais Pesados , Poluentes Químicos da Água , Animais , Cádmio , Monitoramento Biológico , Chumbo , Monitoramento Ambiental , Água , Agricultura , Metais Pesados/análise , Poluentes Químicos da Água/análiseRESUMO
This study aimed to evaluate the anesthetic activity of Ocimum basilicum essential oil and the distribution and depletion of its major compounds in different tissues of the pacu, Piaractus mesopotamicus. Juveniles (319.08 ± 9.14 g) were individually anesthetized with six concentrations of essential oil from O. basilicum (150, 180, 210, 240, 270, and 300 mg L-1), while in a second experiment, fish (492.39 ± 51.51 g) were subjected to a 10 min immersion bath with essential oil from O. basilicum (300 mg L-1). After anesthetic recovery, blood and tissue samples of the brain, gills, liver, spleen, and white muscle were collected at 0, 0.5, 1.0, 3.0, 6.0, 12.0, and 24 h. A 300 mg L-1 concentration induced anesthesia in the shortest time (193.11 ± 9.31), while at 270 and 300 mg L-1 concentrations, the anesthetic recovery period was the longest (244.33 ± 12.44) Methyl chavicol and linalool were quantified in all tissue samples. The plasma concentrations of methyl chavicol differed (p < 0.05) at all evaluated times. Linalool decreased (p < 0.05) from 0 to 1 h and decreased again only after 12 h. Reduction percentages in 24 h were 92.9% for methyl chavicol, and 97.2% for linalool. Elimination of the compounds methyl chavicol and linalool is slower in the gills, where lower elimination constants (0.03 and 0.15 per h) and longer half-lives (25.84 and 4.53 h), respectively, are noted. In general, essential oil from O. basilicum compounds was readily eliminated, showing promising potential for use as an anesthetic in aquaculture.
Assuntos
Monoterpenos Acíclicos , Derivados de Alilbenzenos , Anestésicos , Anisóis , Ocimum basilicum , Óleos Voláteis , Animais , Cromatografia Gasosa-Espectrometria de Massas/veterinária , Óleos de Plantas/farmacologia , Óleos Voláteis/farmacologia , Anestésicos/farmacologiaRESUMO
The determination of mean intensity of parasitism for colony-forming sessile protozoan such as Epistylis has been a great problem in parasitological studies. Some alternatives have been proposed by researchers for laboratory and field conditions. This study describes the criteria to establish the parasitic intensity score for epistylidid infestation in fish. Parasite distribution and the host-parasite relationship in four species of Brazilian cultured catfish and their hybrids are discussed. The highest prevalence rates were found in the hybrid jundiara, Leiarius marmoratus male × Pseudoplatystoma reticulatum female (96.4 %), followed by jurupoca, Hemisorubim platyrhynchos (60 %), and the hybrid surubim, Pseudoplatystoma corruscans male × P. reticulatum female (52.7 %). Positive correlation between parasitic intensity score and the fish size, weight, and relative condition factor were also observed. These findings indicate that Epistylis infestation in Brazilian catfish is an emerging disease in cultured fish.
Assuntos
Peixes-Gato/parasitologia , Infecções por Cilióforos/veterinária , Doenças dos Peixes/parasitologia , Oligoimenóforos/isolamento & purificação , Carga Parasitária , Animais , Peso Corporal , Brasil , Infecções por Cilióforos/parasitologia , Feminino , MasculinoRESUMO
Fish parasites are excellent bioindicators of environmental contamination because they respond quickly to water pollutant chemicals, and they can accumulate high concentrations of trace metals compared to their hosts. Here, we investigated the bioaccumulation pattern of the following: Cd, Ca, K, Na, Mg, Fe, Al, Zn, Ba, Mn, Cu, Pb, Cr, Ni, and Co. We investigated the presence of trace metals in the acanthocephalan parasite Neoechinorhynchus buttnerae, and the bioaccumulation factors (BAFs) of metals were tested in the food, muscle, and liver of its host fish Colossoma macropomum (tambaqui). We used samples from four commercial fish farms that also conduct other agribusiness activities. Tissues of the fish along with their parasites were subjected a trace metal concentration analysis by inductively coupled plasma optical emission spectrometry. Most of metals showed significantly higher presence in N. buttnerae than in tambaqui (p < 0.05), with increased level of Na, Pb, Ca, Mn, Zn, Al, and Fe in fish muscle and that of Cr, Ni, Zn, Al, Ca, and Ba in fish liver. Considering all the fish farms, the highest values of BAF were observed for Fe, Al, Zn, and Mn with concentrations up to 35.63, 26.88, 14.12, and 6.66 times higher in acanthocephalan tissues than in the fish muscle, respectively. Moreover, Ba, Ca, and Al showed concentrations up to 18.11, 12.18, and 11.77 times higher in acanthocephalan than in the liver of tambaqui. Our results indicate that the higher the levels of these metals in the parasite, the lower their concentrations in the muscular and hepatic tissues of the fish. Therefore, we suggest that N. buttnerae can directly influence the concentrations of trace metals in the fish tissues and accumulate both essential trace (Fe, Zn, Mn, and Ca) and toxic elements (Al, Pb, and Ba) in the host.
Assuntos
Caraciformes , Metais Pesados , Animais , Pesqueiros , Bioacumulação , Chumbo/análise , Músculos/química , Metais Pesados/análise , Monitoramento Ambiental/métodosRESUMO
The aim of this study was to observe how abiotic and biotic factors in a tropical region influence the rate of monogenean parasitism in Nile tilapia (Oreochromis niloticus) that are farmed in net cages. A total of 240 sexually reversed fish were analyzed, and 20 from each culture stage were collected during each sampling month. Overall, 60 fish were sampled in April (autumn), 60 in August (winter), 60 in November (spring), and 60 in February (summer). Fish were collected from a commercial fish farm located in Capivara Reservoir in the lower Paranapanema River region of Paraná, Brazil. In total, 3290 monogenean parasites were collected from fish gills of the following species: Cichlidogyrushalli, C. thurstonae, Scutogyruslongicornis, C. cirratus, C. sclerosus, and C. tilapiae. Higher parasitological indices were observed in colder seasons with lower precipitation. Autumn had the highest parasitic infection values compared to the other seasons. The occurrence of monogenean parasites showed a negative correlation with season, in contrast to the culture stage, in which there was a positive correlation. These results may provide a means for establishing adequate fish farm management to predict periods of high monogenean infestation.
RESUMO
Trichodinids are problematic ectoparasites for intensive arapaima fish farming, which can make their breeding costly and unprofitable. The search for effective and safe therapeutic molecules is constant, and chloramine-T has stood out as an effective biocide to treat various pathogens in aquaculture. Here we investigated the acute toxicity (LC50-4h) of chloramine-T and its behavioural, morphological, histological, physiological, and antiparasitic effects on the control of trichodinids in arapaima juveniles. Initially arapaima were exposed to chloramine-T (0, 10, 20, 40, 50, 60, 80, 100 mg L-1) for 4 h. During this period, behavioural, morphological, and mortality changes were recorded. Immediately after a toxicity test, gills were collected for the histological analysis. The LC50-4h was calculated at 23.8 mg L-1 of chloramine-T. Behavioural changes like erratic swimming, loss of balance, gasping at the water surface, excessive mucus, jumping at the water surface, lethargy and gill hyperventilation, and morphological changes like loss of scales, ocular opacity, and skin darkening, were considered mild in arapaima exposed to 10 and 20 mg L-1 of chloramine-T for 4 h. The arapaima gills exposed to 10, 20 and, 40 mg L-1 of chloramine-T presented epithelial hyperplasia, dilated venous sinus and eosinophilic infiltrate, but they were reversible and of a low pathological degree. Based on the acute toxicity test (LC50-4h) results, concentrations were defined for the in vivo efficacy test, during which arapaima were exposed to 0, 10, 15, and 20 mg L-1 of chloramine-T for 1 h. After a therapeutic bath, physiological and parasitological analyses were performed. The use of 20 mg L-1 of chloramine-T significantly reduced (p < 0.05) parasitism by Trichodina sp. with an efficacy of 50.27 % and 53.23 % in gills and on the body surface, respectively. Chloramine-T did not change haematological parameters (erythrogram and thrombogram) or the biochemical parameters of arapaima after 1 h of exposure. However, monocytosis and neutrophilia were noted at slightly higher concentrations (15 and 20 mg L-1), but changes in fish homeostasis were not characterised. Thus, we demonstrate that the application of a therapeutic bath with 20 mg L-1 of chloramine-T for 1 h reduces parasitism by trichodinids and does not affect general arapaima juvenile health.
Assuntos
Peixes , Brânquias , Animais , Aquicultura , Cloraminas , Peixes/anatomia & histologia , Peixes/fisiologia , Brânquias/parasitologia , Compostos de TosilRESUMO
The objective of this study was to investigate the parasites occurrences and to determine the rates of infestation/parasitic infection in juvenile Arapaima gigas from seven fish farms in the state of Amazonas, relating to the characteristics of these fish farms. Of the 70 A. gigas evaluated, 43 were infested/infected, with a total of 133 parasites collected. Three fish farms (2, 4, 6) showed the highest levels of prevalence of parasites (100%, 70%, 70%), mean intensity (4.1±2.6, 8.1±9.2, and 2.1±1.3), and mean abundance (4.1±2.6, 5.7±8.1, and 1.5±1.5), respectively. Prevalence ranged from 30% to 100%, mean intensity from 1.0 to 8.1 and mean abundance from 0.3 to 5.7. Monogenea, Digenea, Nematoda (Hysterothylacium sp. and Spirocamallanus sp.) and Acanthocephala (Neoechinorhynchus sp. and Polyacanthorhynchus sp.) were identified. The parasites Hysterothylacium sp. and Neoechinorhynchus sp. were the most prevalent parasites with 31.43% and 15.71%, respectively. The fish presented negative allometry in growth and constant condition factor. Measures to prevent and control the parasitic diseases diagnosed are discussed as well prophylactic practices that contribute to the biosecurity of the farms.
Assuntos
Acantocéfalos , Ascaridoidea , Doenças dos Peixes , Parasitos , Trematódeos , Animais , Pesqueiros , Brasil/epidemiologia , Peixes/parasitologia , Doenças dos Peixes/epidemiologia , Doenças dos Peixes/parasitologiaRESUMO
This study evaluated the parasitic fauna of hybrids tambacu (Colossoma macropomum × Piaractus mesopotamicus) and patinga (P. mesopotamicus × Piaractus brachypomus) and their host-parasite-environment interaction during the warm and cold seasons in two fish farms located in the State of Mato Grosso do Sul, Brazil, South America. A total of 120 fish, being 60 fish for species (30 in the warm season and 30 in the cold season) were examined. Water quality was measured weekly to evaluate the interaction between environmental conditions and parasitism. Fifteen species of parasites were found: Ichthyophthirius multifiliis, Chilodonella hexasticha e Trichodina sp. (Protozoa), Henneguya piaractus, Myxobolus colossomatis and Myxobolus cuneus (Myxozoa); Anacanthorus penilabiatus, Mymarothecium boegeri, Mymarothecium viatorum, and Notozothecium janauachensis (Monogenoidea), Goezia spinulosa and Goezia sp. (Nematoda), Echinorhynchus jucundus (Acanthocephala), and Dolops carvalhoi, Lernaea cyprinacea (Crustacea). The ciliate protozoan I. multifiliis and monogenoids were the most prevalent parasites in the cold and warm seasons for both hybrids in the different culture systems intensive production and sportive fishing. It was observed that the serrasalmid hybrids are more susceptible to parasites and harbor high diversity of parasites in relation to the parental species C. macropomum, P. mesopotamicus and P. brachypomus, with a predominance of ectoparasites.
Assuntos
Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Parasitos/classificação , Animais , Aquicultura , BrasilRESUMO
Infections negatively influence the production of tambaqui, and in north Brazil, the wide distribution of this parasitic disease has generated concern among fish farmers. The objective of this study was to review published literature on this pathogen. Six main online research databases were searched using the keywords "Neoechinorhynchus buttnerae", "acantocefalose", and "acanthocephalan fish". Based on a set of predetermined criteria, 39 publications were selected for this review. The mechanism of pathogenic action of N. buttnerae is related to the degree of penetration of the proboscis. Infection results in histopathological and morphological changes in the host. The recurrence of the parasite in the northern region was greater twelve years after their first occurrence. The lack of specific legislation on veterinary products for aquatic animals, combined with the neglect of good management practices, and the absence of a contingency plan for the control of acanthocephalan infections have contributed to the current health situation of Colossoma macropomum northern Brazil. Additional information about the occurrence of the disease, pathogenicity, and control of acanthocephalan infections are imperative for developing a disease contingency plan in the region and research to address these should be encouraged by the sector.
Assuntos
Doenças dos Peixes , Helmintíase Animal , Doenças Parasitárias , Animais , Aquicultura , Brasil , VirulênciaRESUMO
Infection by the acantocephalan Neoechinorhynchus buttnerae is considered one of most important concerns for tambaqui fish (Colossoma macropomum ) production. Treatment strategies have been the focus of several in vivo studies; however, few studies have been undertaken on in vitro protocols for parasite maintenance. The aim of the present study was to develop the best in vitro culture condition for N. buttnerae to ensure its survival and adaptation out of the host to allow for the testing of substances to be used to control the parasite. To achieve this, parasites were collected from naturally infected fish and distributed in 6-well culture plates under the following treatments in triplicate: 0.9% NaCl, sterile tank water, L-15 Leibovitz culture medium, L-15 Leibovitz + agar 2% culture medium, RPMI 1640 culture medium, and RPMI 1640 + agar 2% culture medium. The plates containing the parasites were maintained at 24 °C, 28 °C, and 32 °C. The RPMI 1640 + agar 2% culture medium showed the best survival of 24 days at 24 °C. No body alterations such as swollen parasites, body deformation, dehydration and hardening were observed in the RPMI 1640 + 2% culture medium.
Assuntos
Acantocéfalos/crescimento & desenvolvimento , Temperatura , Animais , Caraciformes/parasitologia , Meios de CulturaRESUMO
The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.13% for Dolops geayi. The greatest mean parasite intensity was found in acantocephalans followed by monogeneans and branchiuran crustaceans. A negative correlation was observed between abundance of N. buttnerae and hematocrit percentage, hemoglobin concentration, total thrombocyte count and glucose and between abundance of the monogenean and glucose concentration. Parasitic infections caused damage in tambaqui in terms of the observed hematological parameters that were characterized by hypochromic anemia and thrombocytopenia, which are important parameters to be used in parasitic diagnosis. This study is the first record of the occurrence of Dolops geayi in farmed tambaqui in the Amazon.
Assuntos
Arguloida , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , Helmintos/classificação , Animais , Aquicultura , Caraciformes/sangue , Doenças dos Peixes/sangue , Helmintíase Animal/sangueRESUMO
This study evaluated the parasite fauna of farmed hybrid surubim (Pseudoplatystoma reticulatum x P. corruscans) and the host-parasite-environment relationship in two fish farms located in Mato Grosso do Sul, Central Brazil, South America. A total of 120 hybrids from two different farms, 60 in each season (30 in the hot and 30 in cold season) were examined during a year. Water quality was weekly measured to evaluate the interaction among environmental conditions and parasitism. Histopathology was used to observe the effects of the parasites and environment on the fish gills. The ciliate protozoan Ichthyophthirius multifiliis and the monogeneans (Ameloblastella sp., Amphocleithrium paraguayensis, Vancleaveus ciccinus, V. fungulus and V. janacauensis) were the most prevalent parasites detected in both seasons in both farms, with prevalence above 80%. It was stated that parasites did not cause important damage in the health status of the hybrid surubim. These results might be related to general good management practices and environmental quality implemented by the fish farmers. The presence of uncommon monogenean parasites to this hybrid compared to their parents causing an environmental and ecological concern is here discussed.
Assuntos
Peixes-Gato/parasitologia , Quimera/parasitologia , Doenças dos Peixes/parasitologia , Trematódeos , Infecções por Trematódeos/veterinária , Animais , Brasil , Infecções por Trematódeos/parasitologiaRESUMO
This study evaluated the influence of diet supplementation with propolis and Aloe barbadensis on hematological parameters and parasitism in tilapia. One hundred and eighty fish were distributed among 12 water tanks forming four treatments: fish supplemented with a 1:1 mixture of 0%, 0.5%, 1% and 2% propolis and aloe extracts. After the fish had been fed on the experimental diets for 15 and 21 days, blood samples were taken and parasites collected. The monogeneans Cichlidogyrus sclerosus, C. halli, C. thurstonae and Scutogyrus longicornis were identified in the gills. Between the sampling times, there were increases in the numbers of erythrocytes, leukocytes, thrombocytes and lymphocytes, as observed after 21 days, possibly due to the stress level over the course of the assay and/or accumulation of substances in the organism. Supplementation with the mixture of propolis and aloe for 15 days showed the highest efficacy against the parasites. This was possibly due to the association between the two compounds. The results demonstrated that supplementation with mixtures of extracts did not produce hematological alterations and also favored a significant reduction in the number of gill parasites. The best results were achieved after 15 days of feeding with a diet with 0.5% and 1% supplementation with the extract mixture, which increased efficiency by 83 and 85% respectively.
Assuntos
Aloe , Ciclídeos/sangue , Ciclídeos/parasitologia , Suplementos Nutricionais , Extratos Vegetais/farmacologia , Própole , AnimaisRESUMO
This study evaluated the correlation of hematological parameters with the mean abundance of the monogenean helminth Rhabdosynochus rhabdosynochus in Centropomus undecimalis reared at different temperatures and salinities. The experimental conditions were: 28 °C/0 ppt (parts per thousand); 28 °C/15 ppt; 28 °C/32 ppt; 25 °C/0 ppt; 25 °C/15 ppt; and 25 °C/32 ppt. The prevalence was 100.0% in fish at 28 °C/15 ppt, 28 °C/32 ppt and 25 °C/15 ppt, which was significantly different (p < 0.05) from those at 25 °C/32 ppt. The red blood cell (RBC) count, hematocrit and total leukocyte (WBC) count were significantly higher in fish at 28 °C/15 ppt and 28 °C/32 ppt. The mean abundance of R. rhabdosynochus, hematocrit and RBC showed positive correlations (P < 0.05) with temperature (ρ= 0.3908; ρ= 0.4771 and ρ = 0.2812). Mean abundance showed negative correlations with hemoglobin (ρ= -0.3567) and mean corpuscular hemoglobin concentration (MCHC) (ρ = -0.2684). No correlation between abundance and salinity was detected among the experimental conditions (ρ = -0.0204). The low numbers of monogeneans recorded (min -1 and max -33) explain the few changes to fish health. This suggests that these experimental conditions may be recommended for development of rearing of C. undecimalis in Brazil, without any influence or economic losses from R. rhabdosynochus.
Assuntos
Doenças dos Peixes/parasitologia , Perciformes/parasitologia , Trematódeos/fisiologia , Animais , Feminino , Nível de Saúde , Masculino , Salinidade , TemperaturaRESUMO
Abstract Infection by the acantocephalan Neoechinorhynchus buttnerae is considered one of most important concerns for tambaqui fish (Colossoma macropomum ) production. Treatment strategies have been the focus of several in vivo studies; however, few studies have been undertaken on in vitro protocols for parasite maintenance. The aim of the present study was to develop the best in vitro culture condition for N. buttnerae to ensure its survival and adaptation out of the host to allow for the testing of substances to be used to control the parasite. To achieve this, parasites were collected from naturally infected fish and distributed in 6-well culture plates under the following treatments in triplicate: 0.9% NaCl, sterile tank water, L-15 Leibovitz culture medium, L-15 Leibovitz + agar 2% culture medium, RPMI 1640 culture medium, and RPMI 1640 + agar 2% culture medium. The plates containing the parasites were maintained at 24 °C, 28 °C, and 32 °C. The RPMI 1640 + agar 2% culture medium showed the best survival of 24 days at 24 °C. No body alterations such as swollen parasites, body deformation, dehydration and hardening were observed in the RPMI 1640 + 2% culture medium.
Resumo A infecção pelo acantocéfalo Neoechinorhynchus buttnerae é considerada uma das preocupações mais importantes para produção de tambaqui (Colossoma macropomum). Estratégias de tratamento têm sido o foco de vários estudos in vivo ; entretanto, poucos estudos foram realizados em protocolos in vitro para manutenção do parasito. O objetivo deste estudo foi desenvolver a melhor condição de cultura in vitro para N. buttnerae para garantir sua sobrevivência e adaptação fora do hospedeiro, a ser utilizado para teste com substâncias no controle do parasito. Para isso, os parasitos foram coletados de peixes naturalmente infectados e distribuídos em placas de cultura de 6 poços sob os seguintes tratamentos em triplicata: 0.9% NaCl, água estéril do tanque, meio de cultura L-15 Leibovitz, meio de cultura L-15 Leibovitz + ágar 2%, meio de cultura RPMI 1640, e meio de cultura RPMI 1640 + ágar 2%. As placas contendo os parasitos foram mantidos a 24 °C, 28 °C, e 32 °C. O meio de cultura RPMI 1640 + ágar 2% apresentou a melhor sobrevivência de 24 dias a 24 °C. Nenhuma alteração corporal tais como inchaço dos parasitos, deformação corporal, desidratação e endurecimento foram observados no meio de cultura RPMI 1640 + ágar 2%.
Assuntos
Animais , Temperatura , Acantocéfalos/crescimento & desenvolvimento , Meios de Cultura , Caraciformes/parasitologiaRESUMO
Abstract The aim of this study was to evaluate the impacts of metazoan parasites on hematological and biochemical parameters and relative condition factor of tambaqui (Colossoma macropomum ) farmed in northern Brazil. A total of 32 juvenile fish were captured from a commercial fish farm located in the municipality of Rio Preto da Eva, Amazonas state, Brazil. Parasite prevalence was 100% for Anacanthorus spathulatus, Mymarothecium boegeri and Notozothecium janauachensis, 100% for Neoechinorhynchus buttnerae and 53.13% for Dolops geayi. The greatest mean parasite intensity was found in acantocephalans followed by monogeneans and branchiuran crustaceans. A negative correlation was observed between abundance of N. buttnerae and hematocrit percentage, hemoglobin concentration, total thrombocyte count and glucose and between abundance of the monogenean and glucose concentration. Parasitic infections caused damage in tambaqui in terms of the observed hematological parameters that were characterized by hypochromic anemia and thrombocytopenia, which are important parameters to be used in parasitic diagnosis. This study is the first record of the occurrence of Dolops geayi in farmed tambaqui in the Amazon.
Resumo O objetivo deste estudo foi avaliar o impacto do parasitismo por metazoários sobre os parâmetros hematológicos, bioquímicos e fator de condição relativo de tambaquis (Colossoma macropomum) cultivados na região Norte do Brasil. Foram coletados 32 tambaquis em fase de engorda numa piscicultura comercial no município de Rio Preto da Eva, estado do Amazonas, Brasil. A prevalência de parasitos foi de 100% para Anacanthorus spathulatus, Mymarothecium boegeri e Notozothecium janauachensis, 100% para Neoechinorhynchus buttnerae e 53,13% para Dolops geayi. A maior intensidade média foi de acantocéfalos, seguida por monogenéticos e branquiúros. Correlação negativa significativa foi observada entre abundância de N. buttnerae e os parâmetros de hematócrito, concentração de hemoglobina, trombócitos totais e glicose, bem como entre a abundância de monogenéticos e glicose. A infecção por parasitos metazoários foi capaz de debilitar os tambaquis como observado por meio das alterações hematológicas; sendo este quadro de anemia hipocrômica e trombocitopenia importante para ser utilizado no diagnóstico destas parasitoses. Este estudo foi o primeiro registro da ocorrência de Dolops geayi em tambaquis cultivados na Amazônia.
Assuntos
Animais , Arguloida , Caraciformes/parasitologia , Doenças dos Peixes/parasitologia , Helmintíase Animal/parasitologia , Helmintos/classificação , Aquicultura , Caraciformes/sangue , Doenças dos Peixes/sangue , Helmintíase Animal/sangueRESUMO
Family Trichodinidae comprises ciliate protozoa distributed worldwide; they are considered some of the main parasitological agents infecting cultivated fish. However, the trichodinidae parasitizing important fish species cultured in Brazil are unknown, and more taxonomic studies on this group of parasites are required. This research morphologically characterizes Trichodina colisae Asmat & Sultana, (2005) of pacu (Piaractus mesopotamicus) and patinga hybrid (P. mesopotamicus × P. brachypomus) cultivated in the central and southeast regions of the country. Fresh assemblies were made from mucus scraped from the skin, fins and gills, fixed with methanol and, subsequently, impregnated with silver nitrate and stained with Giemsa for assessment under light microscopy. This research reports not only the second occurrence of T. colisae in the world, but also its first occurrence in South America.