810 resultados para minds on
Resumo:
The aim of this study was to determine the short-term environmental changes caused by the simultaneous passage of a high energy event on two sandy beaches with different morphodynamic states and their influence on the richness, abundance and distribution of the benthic macrofauna. Two microtidal exposed sandy beaches with contrasting morphodynamics were simultaneously sampled before, during and after the passage of two cold fronts in Santa Catarina. The reflective beach showed a higher susceptibility to the increase in wave energy produced by the passage of cold fronts and was characterized by rapid and intense erosive processes in addition to a capacity for rapid restoration of the beach profile. As regards the dissipative beach, erosive processes operated more slowly and progressively, and it was characterized further by a reduced capacity for the recovery of its sub-aerial profile. Although the intensity of the environmental changes was distinct as between the morphodynamic extremes, changes in the composition, richness and abundance of macrobenthos induced by cold fronts were not evident for either of the beaches studied. On the other hand, alterations in the distribution pattern of the macrofauna were observed on the two beaches and were related to variations in sea level, position of the swash zone and moisture gradient, suggesting that short-term accommodations in the spatial structure of the macrobenthos occur in response to changes in environmental conditions in accordance with the temporal dynamics characteristic of each morphodynamic state.
Resumo:
This study investigated the effect of environmental factors on the annual average zonation pattern of benthic macrofauna of sub-aerial profile of three exposed sandy beaches of Santa Catarina with different morphodynamic characteristics. Sampling was carried out between March 2000 and March 2001, with monthly frequency on reflective and dissipative morphodynamic extremes and bimonthly frequency on the intermediate state. Results showed that macrobenthic zonation presented marked differences across the morphodynamic spectrum. The main differences observed from reflective to dissipative conditions were: a) increase in the number of species in lower zones of the beach; b) expansion of zones characterized by high water content of sediment and c) increase in the overlapping of zones, mainly on lower levels of the beach. Canonical Correspondence Analysis related these differences to distinctive cross-shore gradients in sediment moisture levels, sediment reworking and mean grain size that exist across the morphodynamic spectrum, showing that it is important to analyze these environmental factors in studies conducted to investigate zonation on microtidal exposed sandy beaches.
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A new genus and species of parasitic copepod (Clausiidae), Spionicola mystaceus, associated with the polychaete Dipolydora armata (Spionidae) is described and figured. The new copepod has an elongate body, 5-segmented antennule, 2-segmented rami on legs 1 and 2, 2 spines representing leg 3, no leg 4, leg 5 well developed and reduced armature elements on feeding limbs. The host is a mollusk-shell borer, collected off São Sebastião Island, State of São Paulo, Brazil.
Resumo:
Although the rio Capivari basin is recognized as an area of great importance for the ichthyofauna, it lacks virtually every basic requirement for the definition of appropriate conservation strategies, since not even its species composition is known. The objective of this work is to determine the composition and distribution of fish species in the upper rio Capivari basin, relating them to the local physical features, and to evaluate the effectiveness of proposed conservations units, delimited based on areas of native vegetation remains, on the conservation of local ichthyofauna. During 2007, 50 different watercourses were sampled with gillnets, cast nets and kick nets. A total of 1308 individuals belonging to 41 species were captured. Degree of conservation, altitude and width were the parameters that best explained fish species richness. Considering the recently proposed boundaries for potential conservation units in the region only 15 or 20 out of 41 species would be found in the State Park and Environmental Protection Area respectively. In practice, the proposed conservation units would not be effective tools for fish conservation, since it would be located in mountainous areas of high altitude, of headwaters streams and where few species are found. In such context, the conservation of specific stretches of larger rivers is critical.
Resumo:
A new species of the formerly monotypic genus Trichogenes is described from a high-altitude stream of the rio Itapemirim system, an isolated Atlantic drainage in the State of Espírito Santo, southeastern Brazil. Trichogenes claviger, new species, differs from all other trichomycterids by the sexually dimorphic posterior process of the opercle, much elongated in males; the terminal mouth; the deeply bifurcated anterior neural spines and the presence of a large anterodorsal claw-like process on the neural arches of the anterior four free vertebrae. The new species also differs from its only congener, T. longipinnis, by a number of additional traits, including the the lack of branched anal-fin rays in specimens of any size; the broader than long posterior nostril; the deeper head (head depth 72.9-86.6% HL); the presence of a fine dark line along the base of the anal fin; the lack of dark spots on cheeks; the shape of the interopercle; the presence of odontodes on a bony expansion on the posterodorsal margin of the interopercle; the fewer vertebrae (35); the absence of an antorbital; and the fewer pleural ribs (eight). Small juveniles of the new species are also strikingly different from those of all other Trichomycteridae, including T. longipinnis, having a very large lateral eye, an upturned mouth, and compressed head. Trichogenes claviger occurs in shaded sectors of a blackwater sluggish stream with sandy substrate and patchy accumulations of vegetable debris, a habitat markedly different from the rocky torrential environment known for T. longipinnis. A comparison of the internal anatomy of the two species provides the basis for a hypothesis of a monophyletic Trichogenes. Data from the new species further support a sister-group relationship between Trichogeninae and Copionodontinae, as well as the position of that clade as sister group to all remaining Trichomycteridae.
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The present contribution explores the impact of the QUALIS metric system for academic evaluation implemented by CAPES (Coordination for the Development of Personnel in Higher Education) upon Brazilian Zoological research. The QUALIS system is based on the grouping and ranking of scientific journals according to their Impact Factor (IF). We examined two main points implied by this system, namely: 1) its reliability as a guideline for authors; 2) if Zoology possesses the same publication profile as Botany and Oceanography, three fields of knowledge grouped by CAPES under the subarea "BOZ" for purposes of evaluation. Additionally, we tested CAPES' recent suggestion that the area of Ecology would represent a fourth field of research compatible with the former three. Our results indicate that this system of classification is inappropriate as a guideline for publication improvement, with approximately one third of the journals changing their strata between years. We also demonstrate that the citation profile of Zoology is distinct from those of Botany and Oceanography. Finally, we show that Ecology shows an IF that is significantly different from those of Botany, Oceanography, and Zoology, and that grouping these fields together would be particularly detrimental to Zoology. We conclude that the use of only one parameter of analysis for the stratification of journals, i.e., the Impact Factor calculated for a comparatively small number of journals, fails to evaluate with accuracy the pattern of publication present in Zoology, Botany, and Oceanography. While such simplified procedure might appeals to our sense of objectivity, it dismisses any real attempt to evaluate with clarity the merit embedded in at least three very distinct aspects of scientific practice, namely: productivity, quality, and specificity.
Resumo:
The mature larva and pupa of Fulgeochlizus bruchi (Candèze, 1896) are described and illustrated. Bioluminescent patterns are also given. Comments, new data on the first instar larva and natural history data are presented. The first instar larvae differ from the mature larvae mainly in their chaetotaxy, which is sparse and more symmetrically distributed.
Resumo:
We present a molecular phylogenetic analysis of caenophidian (advanced) snakes using sequences from two mitochondrial genes (12S and 16S rRNA) and one nuclear (c-mos) gene (1681 total base pairs), and with 131 terminal taxa sampled from throughout all major caenophidian lineages but focussing on Neotropical xenodontines. Direct optimization parsimony analysis resulted in a well-resolved phylogenetic tree, which corroborates some clades identified in previous analyses and suggests new hypotheses for the composition and relationships of others. The major salient points of our analysis are: (1) placement of Acrochordus, Xenodermatids, and Pareatids as successive outgroups to all remaining caenophidians (including viperids, elapids, atractaspidids, and all other "colubrid" groups); (2) within the latter group, viperids and homalopsids are sucessive sister clades to all remaining snakes; (3) the following monophyletic clades within crown group caenophidians: Afro-Asian psammophiids (including Mimophis from Madagascar), Elapidae (including hydrophiines but excluding Homoroselaps), Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae, and Xenodontinae. Homoroselaps is associated with atractaspidids. Our analysis suggests some taxonomic changes within xenodontines, including new taxonomy for Alsophis elegans, Liophis amarali, and further taxonomic changes within Xenodontini and the West Indian radiation of xenodontines. Based on our molecular analysis, we present a revised classification for caenophidians and provide morphological diagnoses for many of the included clades; we also highlight groups where much more work is needed. We name as new two higher taxonomic clades within Caenophidia, one new subfamily within Dipsadidae, and, within Xenodontinae five new tribes, six new genera and two resurrected genera. We synonymize Xenoxybelis and Pseudablabes with Philodryas; Erythrolamprus with Liophis; and Lystrophis and Waglerophis with Xenodon.
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A new species of Trachycorystes from the rio Aripuanã, above Dardanelos and Andorinhas falls, is described. The new species is distinguished from the only other species of the genus, T. trachycorystes, by the following characteristics: jaws of equal length (vs. lower jaw prognathous in T. trachycorystes); skull roof covered by thick (vs. thin) integument; inner mental barbel very thin and short not reaching base of outer barbel (vs. extending to or beyond base of outer mental barbel); dorsal-fin spine serrated posteriorly, smooth or rough anteriorly (vs. serrated anteriorly and smooth or rough posteriorly); caudal fin shallowly forked (vs. emarginate); and gas bladder simple, without diverticula (vs. with three posterior diverticula). Comments and data on the nominal species Trachycorystes trachycorystes are provided. Trachycorystes cratensis Miranda Ribeiro, 1937, is allocated to the genus Trachelyopterus Valenciennes, 1840, and another local catfish species, Parotocinclus aripuanensis Garavello, 1988, has its type locality reassigned.
Resumo:
A new species of Leporinus Agassiz is described from the rio Curuá, a tributary of the rio Iriri, rio Xingu basin, Serra do Cachimbo, Pará State, Brazil. The new species is diagnosed by the color pattern, which consists of eight to ten midlateral round dark blotches plus 20 to 40 smaller ones scattered over the body, dental formula 3/4, subinferior to inferior mouth, 37 to 38 lateral line scales, 4/3-4 transversal series of scales, and 12 circumpeduncular scale series. The new species most closely resembles L. octomaculatus and L. reticulatus from the upper Tapajós basin, and L. marcgravii and L. microphthalmus from the rio São Francisco and the rio Paranaíba, respectively. Based on recently collected specimens, L. reticulatus is re-diagnosed as having an allometric elongation of the snout.
Resumo:
A new species of the genus Leporinus is described from the rio Araguaia, in Mato Grosso and Goiás states, Brazil. The new species has the dental formula 4/3, a unique feature within the genus; all other species of Leporinus have dental formulae 3/3, 3/4 or 4/4. In addition, the new species can also be distinguished by the following combination of characters: 36 to 37 scales in the lateral line, 4/4.5 or 4/5 series of scales in the transversal line, 16 circumpeduncular scale series, anal fin surpassing base of lower caudal-fin rays and three blotches along the lateral line. The new species shares with L. parae and L. lacustris a rather deep body, terminal mouth, long anal fin, three small dark blotches on the lateral line, the latter two, particularly the last one, usually fading, and preference for lentic habitats. Comments on the taxonomy and distribution of the species L. parae and L. lacustris are provided.
Resumo:
Simopelta minima (Brandão, 1989) was originally described based on four workers collected in soil samples from a small cocoa plantation in Ilhéus, state of Bahia, northeastern Brazil. In the subsequent years after the description, this cocoa plantation was eliminated and the species was then considered extinct by the Brazilian environmental institutions. The recent rediscovery of S. minima workers in subterranean pitfall trap samples from Viçosa, state of Minas Gerais, southeastern Brazil, over 1.000 km distant from type locality, suggests that the rarity and vulnerability status of some ant species may be explained by insufficient sampling of adequate microhabitats, in time and space.
Resumo:
The arguments for the usage of the names Gnathoplax, Roeboexodon, R. geryi, and R. guyanensis are revised. Based on the literature and museum specimens, we recommend that the neotype of Exodon guyanensis should be considered valid; that the genus Gnathoplax should be considered an objective junior synonym of Roeboexodon; and that Roeboexodon geryi should be considered an objective junior synonym of Exodonguyanensis.
Resumo:
A new species of Jupiaba is described from rio Curuá, a tributary of the rio Iriri, rio Xingu basin, Pará State, Brazil. The new species is distinguished from its congeners by the unique combination of teeth cusps of similar size, dentary teeth gradually decreasing in size towards posterior portion, color pattern consisting of dark markings on the base of the majority of lateral body scales, inconspicuous dark elongate humeral blotch and conspicuous dark round blotch on the caudal peduncle, and 21 to 24 branched anal-fin rays. The new species is very similar, and possibly sister taxon to J. meunieri. Comments on the endemism of the fish fauna of the upper rio Curuá are given.
Resumo:
The only specimen listed in the original description of Scyllarides deceptor Holthuis, 1963 is the holotype from São Paulo, Brazil, presently housed in the Leiden Museum. From the original description, however, it is clear that the new species was actually based on a number of additional specimens. Six of them exist in the collections of the Museum of Zoology in São Paulo, and are shown herein to be paratypes of S. deceptor. Scyllarides deceptor and S. brasiliensis Rathbun, 1906, continue to be confounded with one another, in consequence of their very similar color patterns and locally sympatric distributions. As many as 251,786 tons of slipper lobsters have been landed in Santa Catarina between 2000 and 2007. These catches have been attributed to S. deceptor alone and did not take into consideration the existence of a second species in the area, S. brasiliensis. Correct recognition of slipper-lobster species will be critical to properly evaluate the lobster stocks in southeastern Brazil. An opportunity is taken herein to elaborate on the taxonomy of S. deceptor and S. brasiliensis.