1,721,055 research outputs found
Múltiples roles de los parásitos en la naturaleza: componentes determinantes e indicadores de la biodiversidad
No full textLos parásitos son componentes ubicuos de la naturaleza y conforman una proporción relevante de la biodiversidad, la que en general permanece poco conocida. Su influencia sobre diversos aspectos de la biología y ecología de los organismos que los albergan puede afectar las poblaciones de los mismos y, porlo tanto, sus comunidades y ecosistemas. Además, los parásitos explotan características biológicas de sus hospedadores individuales y de sus poblaciones y comunidades para asegurar su transmisión, supervivencia y el mantenimiento de poblaciones viables. En consecuencia, el conocimiento de la biología parasitaria brinda un conjunto de herramientas para la interpretación de diferentes aspectos de la biología de sus hospedadores, muchas de ellas relacionadas a estimaciones de la biodiversidad. Asimismo, en los escenarios presentes y futuros de cambio global, los parásitos son fuentes confiables de evidencia en estudios de impacto ambiental sobre poblaciones de hospedadores, sobrepesca, polución, disminución de la biodiversidad, monitoreo de áreas marinas protegidas, etc. Así, se analizarán estos tres aspectos de la biodiversidad parasitaria: el rol delos parásitos como componentes y su efecto como determinantes de la Biodiversidad de los ecosistemas y su utilidad como indicadores de la biodiversidad ante los desafíos actuales de cambio global y efectos antrópicossobre los sistemas naturales.Fil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaVIII Congreso Argentino de ParasitologíaCorrientesArgentinaAsociación Parasitológica Argentin
Parasites in fisheries and mariculture
Get PDFTraditionally, parasitology has been concerned with the harmful effects of parasitic organisms; it is basically an applied science. Since its founding in the field of medicine, and later in veterinary medicine, parasitology has been mainly devoted to generating knowledge, which is applicable to parasite control and management, and eventually to their eradication. However, the complexity of parasitism, as revealed over recent decades by workers in various specialisms of parasitology, makes the application of management and control measures very difficult in natural environments. This is particularly true in the marine realm, where however some applied aspects of parasitology, other than those devoted to control and management of parasites, have been shown to be of great importance for fisheries, human health, biological control of introduced species and environmental sciences (Rohde, 2002). The relationship of parasitology with mariculture practices, which are carried out mostly on artificial and controlled systems, follows a more classical approach, focusing on the development of strategies of prevention, management and control of pathogens.Fil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Mackenzie, K.. University Of Aberdeen; Reino Unid
Diplectanum squamatum n. sp. (Monogenea: Diplectanidae) from the gills of Cynoscion guatucupa (Sciaenidae) in Southwest Atlantic waters
Get PDFDiplectanum squamatum n. sp. is described from the gills of the sciaenid Cynoscion guatucupa collected off Mar del Plata, Argentina. The new species is distinguished from other species of the genus by the morphology of the hamuli and the male copulatory organ, and presence of scales on the haptor and body. This is the first species of Diplectanum to be reported from southwest Atlantic waters and, with the possible exception of D. cayennense Euzet & Durette-Desset, 1974, the only species from the Atlantic coast of South America.Fil: Santos, Claudia P.. Universidade Santa Úrsula; Brasil. Instituto Oswaldo Cruz; BrasilFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Gibson, David I. British Museum (Natural History); Reino Unid
A new species of Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) parasitic in the freshwater fish Oligosarcus jenynsii (Günther, 1864) (Characidae) from Argentina
Get PDFNematodes belonging to genus Hedruris Nitzsch, 1821 (Nematoda: Hedruridae) were found in the stomach of the freshwater fish Oligosarcus jenynsii (Günther, 1864) (Characidae) from a shallow eutrophic lake in Argentina. Morphological comparisons with congeneric relatives showed that these nematodes belong to a new species, for which H. bifida n. sp. is proposed. Hedruris bifida n. sp. can be distinguished from its congeners by the following combination of characters: bifid deirids, absence of precloacal papillae and nine pairs of postcloacal papillae and non-mammillated eggs. The new species closely resembles Hedruris suttonae Brugni & Viozzi, 2010¸ the only known species from Argentina; however, the bifid deirids in the new species and the distribution pattern of perianal spines in females clearly distinguish both species. Hedruris bifida n. sp. represents the second nominal species of the genus in Argentina and the eighth species described in the Neotropical region.Fil: Rossin, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
Acanthochondria helicoleni sp. nov. (Copepoda: Chondracanthidae) parasitic on Helicolenus lahillei (Scorpaeniformes: Sebastidae) from Argentinean waters
Get PDFA new species of a parasitic copepod, Acanthochondria helicoleni sp. nov. (Copepoda, Chondracanthidae), is described and illustrated from specimens collected within the branchial chambers of the rubio, Helicolenus lahillei Norman, 1937, from the Argentinean waters. The new species most closely resembles A. serrani Braicovich et Timi, 2009 collected in the same region, but differs in the general measurements and proportions of the body; primarily by the relative length of neck, shape of head, shape and size of genito-abdominal tagma and relative size of the trunk postero-lateral processes.Fil: Cantatore, Delfina María Paula. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Timi, Juan Tomas. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Departamento de Biología. Laboratorio de Parasitología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin
Homogeneity of parasite assemblages of Dules auriga (Serranidae) in hydrographically heterogeneous sites
Get PDFParasite assemblages of Dules auriga are described for the first time from samples caught during research cruises in two localities of the Argentine-Uruguayan Common Fishing Zone (AUCFZ) and are compared with four additional samples collected by commercial catches from the same region. A total of 178 fish were examined and 13 parasite species were found. This showed low species richness, a condition observed in some other small benthic species at a low trophic level. The composition of the parasite fauna was similar to those found on other host species in the region, sharing the same set of dominant species with other sympatric fishes, which have been identified as both typical and as indicators of this ecoregion: Grillotia carvajalregorum, Corynosoma australe and Hysterothylacium sp. Multivariate similarity analyses at the infracommunity and the component community levels indicated that the two samples caught at different latitudes in the AUCFZ display almost identical parasite assemblages. This repeatability in assemblage structure was also observed across samples from commercial catches. The homogeneity of the parasite assemblages is considered to be an intrinsic property of fish inhabiting the AUCFZ, independent of their ecology and trophic level.Fil: Braicovich, Paola Elizabeth. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
A new species of Cucullanus (Nematoda: Cucullanidae) parasitizing Conger orbignianus (Pisces: Congridae) from Argentinean waters
Get PDFIn total, 17 specimens of Conger orbignianus Valenciennes, 1847 from waters off Mar del Plata, Argentina (3808S, 5732W) were examined for parasitic nematodes. A new nematode species, Cucullanus pedroi n. sp., is described (prevalence 76.5%, x¯ intensity SD 3.8 2.7). The new species closely resembles some species parasitizing other anguilliform fishes; however, it can be distinguished from most of its congeners by the distribution pattern of caudal papillae (particularly fourth and eight pairs) and phasmids. Those congeners with similar pattern of papillae differ from the new species by the length of the spicules and gubernaculum and by the position of the excretory pore and deirids.Conger orbignianus Valenciennes, 1847 from waters off Mar del Plata, Argentina (3808S, 5732W) were examined for parasitic nematodes. A new nematode species, Cucullanus pedroi n. sp., is described (prevalence 76.5%, x¯ intensity SD 3.8 2.7). The new species closely resembles some species parasitizing other anguilliform fishes; however, it can be distinguished from most of its congeners by the distribution pattern of caudal papillae (particularly fourth and eight pairs) and phasmids. Those congeners with similar pattern of papillae differ from the new species by the length of the spicules and gubernaculum and by the position of the excretory pore and deirids.Fil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Lanfranchi, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
Ontogenetic changes in heterogeneity of parasite communities of fish: disentangling the relative role of compositional versus abundance variability
Get PDFIn order to determine how much of the variability in parasite assemblages is driven by differences in composition or in abundance we used multivariate dispersions (average distance from infracommunities to their size class centroid in the multivariate space) as a measurement of β-diversity in infracommunities of Conger orbignianus, applying a set of dissimilarity measures with different degrees of emphasis on composition versus relative abundance information. To evaluate comparatively the rate of such changes, we also analysed the effect of host size by regressing differences in β-diversity among size classes against differences in mean fish size. Multivariate dispersions varied along an ontogenetic gradient, its significance depending on the measurement used. Larger fish showed higher richness and abundance; however, smaller fish displayed lower variations in abundance but higher in composition. This could be caused by stochastic encounters at low densities due to the overdispersion of parasites in previous hosts. As fish grow, the composition of their parasite assemblages becomes homogenized by repeated exposure, with abundance thus arising as the main source of variability. Both variables act at different rates, with the exponential decay in the compositional variability as differences in fish size increase being about twice as steep as the decay in abundance variability, indicating that compositional homogeneity is reached faster than abundance heterogeneity as fish grow. Discerning between both variables is crucial in order to understand how community structure is formed by size-dependent variability of host populations.Fil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Lanfranchi, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
Dactylogyrid monogeneans parasitising Cyphocharax voga (Hensel) (Teleostei: Curimatidae) from the Pampas region, Argentina: new and previously described species
Get PDFMost studies on dactylogyrid monogeneans in Argentina have been carried out during 1980s and 1990s. Many of these species have been later synonymised and other remain under a confusing taxonomic status, particularly those parasitising Cyphocharax voga (Hensel) (Teleostei: Curimatidae). In order to clarify the identity of dactylogyrids, new material was collected from fishes in Lake Chascomús, Buenos Aires Province, Argentina. A total of four species was found in the gills of C. voga. Two known species, Curvianchoratus singularis (Suriano, 1980) Suriano, 1986 and Palombitrema triangulum (Suriano, 1981) Suriano, 1997, are redescribed and their generic and specific status discussed, and two new species are described. Urocleidoides surianoae n. sp. can be distinguished from its congeners by having an anterior medial projection in the ventral bar and a laminar ligament connecting the base of the male copulatory organ and accessory piece. Annulotrematoides bonaerensis n. sp. differs from its congeners principally by having a ventral bar with an anterior medial projection. The diversity of dactylogyrids harboured by C. voga indicates the need of further studies in the Pampas region, which will provide interesting and valuable sources of evidence for future zoogeographical and evolutionary research on dactylogyrids in the Neotropics.Fil: Rossin, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencia Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; Argentin
Why ignoring parasites in fish ecology is a mistake
No full textParasites are ubiquitous components of biological systems that have evolved in multiple independent lineages during the history of life, resulting in a diversity of taxa greater than that of their free-living counterparts. Extant host-parasite associations are the result of tight reciprocal adaptations that allow parasites to exploit specific biological features of their hosts to ensure their transmission, survival, and maintenance of viable populations. As a result, parasites may affect host physiology, morphology, reproduction or behaviour, and they are increasingly recognized as having significant impacts on host individuals, populations, communities and even ecosystems. Although this is usually acknowledged by parasite ecologists, fish ecologists often ignore parasitism in their studies, often acting as though their systems are free of parasites. However, the effects of parasites on their hosts can alter variables routinely used in fish ecology, ranging from the level of individual fish (e.g. condition factors) to populations (e.g. estimates of mortality and reproductive success) or communities (e.g. measures of interspecific competition or the structure and functioning of food webs). By affecting fish physiology, parasites can also interfere with measurements of trophic levels by means of stable isotope composition, or have antagonistic or synergistic effects with host parameters normally used as indicators of different sources of pollution. Changes in host behaviour induced by parasites can also modify host distribution patterns, habitat selection, diet composition, sexual behaviour, etc., with implications for the ecology of fish and of their predators and prey. In this review, we summarise and illustrate the likely biases and erroneous conclusions that one may expect from studies of fish ecology that ignore parasites, from the individual to the community level. Given the impact of parasites across all levels of biological organisation, we show that their omission from the design and analyses of ecological studies poses real risks of flawed interpretations for those patterns and processes that ecologists seek to uncover.Fil: Timi, Juan Tomas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Poulin, Robert. University of Otago; Nueva Zeland
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