OALib Journal期刊

ISSN: 2333-9721



匹配条件: “Marceniuk” ,找到相关结果约6条。
Revalida??o de Cathorops arenatus e Cathorops agassizii (Siluriformes, Ariidae), bagres marinhos das regi?es norte e nordeste da América do Sul
Marceniuk, Alexandre P.;
Iheringia. Série Zoologia , 2007, DOI: 10.1590/S0073-47212007000400002
Abstract: nominal species from north and northeast south america, traditionally recognized in the literature as synonymous of cathorops spixii (agassiz, 1829), have their specific status redefined. type specimens of arius arenatus valenciennes, 1840, arius fissus valenciennes, 1840, tachisurus agassizii eigenmann & eigenmann, 1888 and arius pleurops boulenger, 1897 were examined. cathorops arenatus and cathorops agassizii are considered valid, cathorops fissus is a junior synonym of cathorops arenatus and cathorops pleurops a junior synonym of cathorops agassizii. the morphometric characters traditionally used in descriptions and keys in the family ariidae are redefined and new characters are used.
Redescri??o de Genidens barbus (Lacépède, 1803) e Genidens machadoi (Miranda-Ribeiro, 1918), Bagres Marinhos (Siluriformes, Ariidae) do Atlantico Sul Ocidental
Marceniuk, Alexandre P.;
Papéis Avulsos de Zoologia (S?o Paulo) , 2005, DOI: 10.1590/S0031-10492005001100001
Abstract: variation in the pattern of the vomero-palatine tooth patches of genidens barbus and genidens machadoi is reviewed and the species redescribed based on the analysis of 46 morphological characters. genidens machadoi can be distinguished from genidens barbus by: the notched lateral margin of the sphenotic (vs. lateral margin of the sphenotic straight); the cephalic shield narrowest in the sphenotic (vs. cephalic shield narrowest in the frontal); distance between the lateral margin of the cephalic shield, at narrowest portion, and the posterior margin of the orbit 0.681.0 of the smallest width of the cephalic shield (vs. 1.21.7); width of the posterior extremity of the supra-occipital process 2.03.4 of the length of the supra-occipital process (vs. 3.34.7); one or two groups of tooth patches on roof of mouth, anterior patch small and round, posterior patch oval, sometimes confluent or fused with the front group (vs. patches a with horseshoe shape, patches totally fused or divided in confluent groups, always with a posterior projection); longest length of the tooth patches 3.24.9 of the height of the head (vs. 1.93.4); granulation on cephalic shield coarse and irregularly distributed (vs. smooth and distributed in regular series).
Revision of the species of the genus Cathorops (Siluriformes: Ariidae) from Mesoamerica and the Central American Caribbean, with description of three new species
Marceniuk, Alexandre P.;Betancur-R., Ricardo;
Neotropical Ichthyology , 2008, DOI: 10.1590/S1679-62252008000100004
Abstract: the ariid genus cathorops includes species that occur mainly in estuarine and freshwater habitats of the eastern and western coasts of southern mexico, central and south america. the species of cathorops from the mesoamerica (atlantic slope) and caribbean central america are revised, and three new species are described: c. belizensis from mangrove areas in belize; c. higuchii from shallow coastal areas and coastal rivers in the central american caribbean, from honduras to panama; and c. kailolae from río usumacinta and lago izabal basins in mexico and guatemala. additionally, c. aguadulce, from the río papaloapan basin in mexico, and c. melanopus from the río motagua basin in guatemala and honduras, are redescribed and their geographic distributions are revised.
A ictiofauna de cabeceiras do rio Tietê, S?o Paulo, Brasil
Marceniuk, Alexandre Pires;Hilsdorf, Alexandre Wagner da Silva;Langeani, Francisco;
Biota Neotropica , 2011, DOI: 10.1590/S1676-06032011000300020
Abstract: a synthesis of the ichthyofauna of the headwaters of the rio tietê, based on material from zoological collections and new samplings, is presented. fifty six species belonging to seven orders and 16 families are recorded to the drainage, increasing previous numbers significantly. the current results show that the headwaters of the rio tietê possess a singular ichthyofauna composition, diverse from that found in the remaining of the upper paraná basin, with high level of endemic species and great similarity to the species from coastal drainages. this finding corroborates the hypothesis of past river capture between streams and rivers in both drainages. among the species occurring in the area surveyed, eight are endemic (14.3%), 13 are found in the headwaters of rio tietê and in the coastal drainages of southeastern brazil (23.2%), 10 are present throughout the upper paraná basin (17.9%), five are found in the upper paraná basin and in the coastal drainages of southeastern brazil (8.9%), while 13 show a broader distribution in the south america drainages (23.2%), part of which still remains to be identified. species diversity increased with the discovery of at least five new species belonging to the genera cyphocharax, characidium, astyanax, pareiorhina and australoheros, and four new records for characidium cf. zebra, scleromystax barbatus, crenicicla britskii and synbranchus cf. marmoratus. at least, seven non-native species are recognized to be established in the region, while 10 other are included in red books.
Color pattern variation in Trichomycterus iheringi (Eigenmann, 1917) (Siluriformes: Trichomycteridae) from rio Itatinga and rio Claro, S?o Paulo, Brazil
Silva, Cristiane C. F. da;Matta, Sara Lívia S. Fernandes da;Hilsdorf, Alexandre W. S;Langeani, Francisco;Marceniuk, Alexandre P;
Neotropical Ichthyology , 2010, DOI: 10.1590/S1679-62252010000100007
Abstract: color pattern is recognized as an important characteristic for diagnosing trichomycterus species and for elucidating their relationships. an analysis based on morphological and molecular data confirms the existence of a single species of trichomycterus in the rio itatinga, a costal river drainage on the escarpment of the serra do mar and the rio claro on the upper course of the rio tietê. the only species found, trichomycterus iheringi, shows two clearly distinct patterns of body pigmentation and intermediate color patterns related to body size and microhabitat preference.
Efeitos de diferentes intensidades de pastejo em pastagem nativa melhorada sobre o desempenho animal
Soares, André Brugnara;Mezzalira, Jean Carlos;Bueno, Emanuel Ant?nio Centenaro;Zotti, Cleimary Fátima;Tirelli, Leila Angela;Cassol, Luis César;Marceniuk, Luzia Vanessa;Adami, Paulo Fernando;Sartor, Laércio Ricardo;
Revista Brasileira de Zootecnia , 2006, DOI: 10.1590/S1516-35982006000100009
Abstract: a grazing trial was carried out to evaluate the effect of two forage masses on the animal yield from natural pasture over-sown with exotic legumes species (white clover - trifolium repens, red clover - trifolium pratense and birdsfoottrifoil - lotus corniculatus). the grazing method consisted of a variable continuous stocking rate over the period from july 2003 to april 2004. the experimental treatments were two forage masses: low forage mass (lfm) (1,021 kg of dm/ha) and high forage mass (hfm) (1,751 kg of dm/ha). pasture and animal evaluations were accomplished nearly at 30 days intervals. heavy treatment ′ experimental period interaction was observed for the stocking rate that showed an average of 690 and 437 kg of dm/ha to lfm and hfm respectively. forage mass affected the animal average daily gain estimates of 480 and 262 g/animal/day for hfm and lfm, respectively, but had no effect on animal body weight yield per unit of land area estimates of 231 and 207 kg/ha for the lfm and hfm, respectively. these results point out that the improved natural pasture management must be accomplished under herbage mass valus near to 1,700 dm/ha, because it maintain good weight gain rate.

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