Manejo e sanidade de peixes em cultivo.

bitstream/item/85112/1/Manejo-e-Sanidade.pdfArtigos em português, espanhol e inglês

Current knowledge on use of essential oils as alternative treatment against fish parasites.

This review article focuses on current knowledge about in vitro and in vivo experimentation relating to use of essential oils (EOs) to combat fish parasites. In addition, we discuss the existing methodologies used in studies to determine the antiparasitic activity of EOs, along with their toxicity and major compounds. The methodological approaches used to describe the anthelmintic properties of EOs were demonstrated. The consistency of their activity and thus their potential use for fish ectoparasites (in vitro and in vivo) and endoparasites (in vitro) control was reviewed. There is a clear need to find EOs and active agents of EOs to treatment in vivo against endoparasites of fish. Thus, progress may be achieved through considering the beneficial aspects of EOs when their complementarity and potentiality are exploited. EOs are therefore viable alternative sources of therapeutic products against fish parasites. On the other hand, use of chemotherapeutics has been increasingly questioned, such that constant environmental and consumer concerns regarding them now exist. The synergistic functions of EOs, in comparison with the action of one or two major compounds of these oils, seems unquestionable. It is possible that their activity is modulated by several molecules of the major compounds. Lastly, EOs are bioactive products that are viable sources of therapy against fish parasites. Although more than 3000 EOs are known, less than 0.4% of them have been tested on fish parasites. Thus, it has become clear that more studies testing these therapeutic alternatives are required, in order to evaluate the antiparasitic potential of other EOs for controlling fish parasites and to maximize their benefits to hosts

Community of protozoans and metazoans parasitizing Auchenipterus nuchalis (Auchenipteridae), a catfish from the Brazilian Amazon.

This paper describes the first study on parasite diversity in Auchenipterus nuchalis Spix & Agassiz, 1829 (Auchenipteridae). In 31 fish caught in a tributary of the Amazon River, 10,708 parasites were collected, such as Ichthyophthirius multifiliis, Piscinoodinium pilullare, Cosmetocleithrum striatuli, metacercariae of Posthodiplostomum sp, and larvae and adults of Procamallanus (Spirocamallanus) inopinatus. These parasite species showed aggregated dispersion, except for C. striatuli, which had a uniform dispersion. The component community of parasites showed a low Brillouin diversity (0.67 ± 0.27), low species richness (3.5 ± 0.8) and low evenness (0.43 ± 0.17), and it was characterized by the presence of species with high prevalence and abundance. Protozoan species were the prevalent parasites, which may be a consequence of the host?s mode of life, while the low presence of endoparasites in A. nuchalis suggests that this fish may occupy an intermediate trophic level in the food web. These data represent the first record of such parasite species for this host

Seasonality affects the parasitism levels in two fish species in the eastern Amazon region.

Fish parasite communities have strong interactions with the environment, the host fish, and the aquatic invertebrate communities. Thus, factors directly involving their different life cycles, such as different host populations and environments, as well as seasonal fluctuations in water levels can cause different responses. The main factors structuring parasite communities may be the hydrodynamic variations, together with seasonal variations in the availability of infectious stages of parasites in the environment. The purpose of this study was therefore to investigate the influence of the rainy and dry seasons on parasite infracommunities in fish species in the Amazon River System of Brazil. Between October 2009 and April 2011, specimens of Colossoma macropomum and Colossoma macropomum x Piaractus brachypomushybrids (tambatinga) were examined for the presence of parasites. The parasite communities were similar in these two species that both showed aggregate dispersion, although the hybrid specimens were less parasitized. For both hosts, the Brillouin diversity, species richness, evenness and Berger-Parker dominance indices were similar in the rainy season and dry season, except that the Berger-Parker dominance index for the C. macropomum x P. brachypomushybrid was higher during the dry season. Ichthyophthirius multifiliis was the dominant parasite, followed by Piscinoodinium pillulare, in both hosts. However, C. macropomumhad a higher prevalence and abundance in the dry season, while in the C. macropomum x P. brachypomushybrid, only the I. multifiliis prevalence increased. The abundance of monogenean species (Anacanthorus spathulatus, Linguadactyloides brinkmanni, Mymarotheciumand Notozothecium janauachensis) was higher during the dry season in the gills of C. macropomum. Despite over dispersion of the lernaeid Perulernaea gamitanae, a seasonal pattern was seen only in the C. macropomum x P. brachypomushybrid, with higher prevalence in the rainy season. The low prevalence and abundance of the ectoparasites Tetrahymenasp., Trichodinasp. and Braga patagonica, as well as of the endoparasites Procamallalus (Spirocamallanus) inopinatus and Neoechinorhynchus buttnerae, were not affected by seasonality. This information is applicable in farming practice for these economically important fish, as it indicates the best time for prophylactic management and treatment against parasites, in order to prevent economic losses in fish farms

Structure of the parasites communities in two Erythrinidae fish from Amazon river system (Brazil).

This study compared the parasite communities of Hoplias malabaricus and Hoplerythrinus unitaeniatus from Amazon river system. Hoplias malabaricus were infected by Ichthyophthirius multifiliis, Piscinoodinium pillulare, Tetrahymena sp., Urocleidoides eremitus, Braga patagonica, metacercariae of Clinostomum marginatum, Procamallanus (Spirocamallanus) inopinatus, larvae of Contracaecum sp. and larvae of Nomimoscolex matogrossensis. Hoplerythrinus unitaeniatus were also infected by these same species of protozoans, nematodes, digeneans and cestodes, except for Tetrahymena sp. and B. patagonica, which were replaced by Argulus pestifer, Urocleidoides sp., Whittingtonocotyle caetei, Whittingtonocotyle jeju and Gorytocephalus spectabilis. For both hosts, I. multifiliis and P. pillulare were the predominant parasites. Most of the parasites presented an overdispersion. Parasite species richness, Brillouin diversity, evenness and Berger-Parker dominance were similar for the two hosts. The length and weight of H. malabaricus showed a positive correlation with the abundance of U. eremitus and Contracaecum sp., while the weight of H. unitaeniatus showed a positive correlation with the abundance of I. multifiliis. The diversity of ectoparasites seemed to be influenced by the behavior of these two hosts. This was shown by the similar parasite communities and was characterized by low species diversity, low evenness and low richness, and by a high prevalence of ectoparasites

Concentração letal (CL50) do óleo essencial de mentha piperita (lamiaceae) em pirarucus arapaima gigas.

Na piscicultura, diversos produtos fitoterápicos vêm sendo usados no tratamento das parasitoses, principalmente causadas por helmintos. Mentha piperita, planta usada na medicina popular para tratar nauseas, vômitos, indigestão, desordens estomacais, cólicas mestruais e verminoses não tem sido testada em peixes, incluindo pirarucu Arapaima gigas. Porém, é importante conhecer a toxicidade de qualquer produto antes de recomendar a sua concentração terapêutica. Este ensaio realizado no Laboratório de Sanidade de Organismos Aquáticos da Embrapa Amapá, Macapá (AP), teve como objetivo determinar a concentração letal média (CL50-4h) do óleo essencial (OE) de M. piperita para pirarucus. Neste ensaio de toxicidade utilizou-se 168 alevinos de pirarucu (34,7 ± 12,4 g e 16,8 ± 2,0 cm) que após aclimatação foram distribuídos aleatoriamente em 14 tanques com volume para 80 L de água e na densidade de 12 peixes/tanque. O delineamento experimental foi inteiramente casualizado, constituído por dois grupos controles (um somente água do cultivo e outro água do cultivo contendo 80 ?L de álcool etílico absoluto) e seis concentrações (20, 40, 80, 100, 130 e 160 mg/L) de OE de M. piperita em duplicatas. As concentrações do OE foram diluídas em álcool etílico (1g:10 mL). Durante o período de 4 horas de exposição ao OE, os peixes foram mantidos sem alimentação, em sistema estático de água e a CL50-4h, foi calculada usando o método de Trimmed Spearman-Karber. Os resultados mostraram que a CL50-4h de M. piperita foi 38 mg/L, com intervalo de confiança (95%) variando de 30-40 mg/L. Portanto, o teste de toxicidade aguda indica que as concentrações clínicas para banhos terapêuticos de pirarucus com OE de M. piperita devem ser abaixo desses valores obtidos, para evitar mortalidade dos peixes, que é indesejada em qualquer piscicultura durante o tratamento antiparasitário.US100

A review of the blood coagulation system of fish.

Uma revisão do sistema de coagulação sanguínea de peixes. Hemostasia é uma função de grande importância para responder a danos e desordens da coagulação sanguínea. Assim, é fundamental para prevenir hemorragia e perda de sangue após um dano vascular, pois o corpo necessita de um mecanismo de coagulação eficiente. Em peixes, apesar de existirem diversos estudos sobre fatores intrínsecos e extrínsecos, algumas questões significantes sobre a regulação do sistema de coagulação permanecem em aberto, uma vez que estes dados estão dispersos na literatura. Esta revisão compara e discute os diversos aspectos dos mecanismos de coagulação em peixes teleósteos, incluindo algumas substâncias relacionadas a este processo, fatores envolvidos na hemostasia, as implicações dos trombócitos no sistema intrínseco da coagulação e diferenças no tempo de coagulação sanguínea