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| Registros recuperados: 45 | |
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| Barla,María J; Vera,María S; O'Brien,Emma D. |
| The Salado River is an important watercourse in northern Pampean region of Argentina which includes several lakes in the upper part of its basin. This upper part shows lesser fish species richness than the lower section of the river. In this paper, an analysis of community structure of secondary and tertiary consumers and its autecology are presented. Among the 14 fish species recorded, 3 were mainly or totally piscivorous as adults. They constituted 11.4% of the numeric abundance and 10.8% of the biomass. Their numeric abundance was 89% (Oligosarcus jenynsii), 11% (Rhamdia sapo), and 0.5% (Hoplias malabaricus malabaricus), and their relative biomass was 61%, 33%, and 6%, respectively. Length/weight ratio, condition factor, and cephalic index indicate that... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Characiformes; Siluriformes; Predation; Biocenology; Lentic environments; Pampean lakes; Trophic levels. |
| Ano: 2003 |
URL: http://www.scielo.org.ar/scielo.php?script=sci_arttext&pid=S1667-782X2003000200009 |
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| Huaquín,Laura G.; Veliz,Dina; Arratia,Gloria. |
| El conocimiento de la estructura ovárica permite analizar la capacidad desovante, duración, temporalidad y forma en que se realiza esta función reproductiva. Se describen y analizan aspectos estructurales de las cubiertas ovocitarias de 2 especies de Siluriformes Nematogenys inermis especie considerada en peligro de extinción y de Trichomycterus areolatus, la más abundante y de mayor distribución en Chile continental. Cortes histológicos de 6 mm de ovarios fijados en Bouin fueron teñidos con HE, Azán, Van Gieson, Alcian Blue y PAS. El estudio histológico muestra la pared del ovario formada por el peritoneo externo, una túnica media y el epitelio ovárico. Desde la túnica se proyectan hacia el interior, láminas de tejido conectivo que van a constituir el... |
| Tipo: Journal article |
Palavras-chave: Histología; Cubiertas ovocitos; Siluriformes. |
| Ano: 2002 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-65382002000200026 |
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| Sofia,Silvia H.; Galindo,Bruno A.; Paula,Francine M.; Sodré,Leda M.K.; Martinez,Cláudia B.R.. |
| In this study, random amplified polymorphic DNA (RAPD) markers were applied to analyze the genetic diversity of samples of the Neotropical catfish Hypostomus ancistroides, collected from four sites (S1, S2, S3 and S4) along an urban stream in Southern Brazil. The 11 primers used in RAPD analysis amplified 147 loci, 76 (51.7%) of which were polymorphic. The proportions of polymorphic loci observed in the four samples were: 29.93% (S1), 31.97% (S2), 23.81% (S3) and 38.77% (S4). The average heterozygosity within sampling localities ranged from 0.1230 to 0.1526 and unbiased genetic distances ranged from 0.0253 to 0.0445. AMOVA partitioned 90.85% of the total variation within samples and 9.15% among samples. Excepting for the sample pair S1-S2 (phiST = 0.02784;... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Loricariid fish; Genetic diversity; RAPD; Siluriformes. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200027 |
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| Milhomem,Susana Suely Rodrigues; Souza,Augusto Cesar Paes de; Nascimento,Aline Lira do; Carvalho Jr.,Jaime Ribeiro; Feldberg,Eliana; Pieczarka,Julio Cesar; Nagamachi,Cleusa Yoshiko. |
| We studied the karyotypes of Hassar cf. orestis and an undescribed Hassar species from the Jarí River and Opsodoras ternetzi, H. orestis and Platydoras cf. costatus from the Xingú River, all with 2n = 58. Constitutive heterochromatin is located in the centromere in most metacentric pairs; in some chromosomes this banding is not present, or it is located on the whole chromosome arm or in the distal regions. The NOR is located on a single biarmed pair at a distal region of the short arm in H. cf. orestis, H. orestis and P. cf. costatus at a distal region of the long arm in O. ternetzi and at a proximal region of the long arm in the Hassar species. In all species (except for Hassar sp.) the CMA3 analysis revealed a rich G-C region coincident with the NOR.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Chromosomes; Amazon; Biodiversity; Siluriformes; Banding; Fluorochromes. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200017 |
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| Colihueque,Nelson; Corrales,Olga; Parraguez,Margarita. |
| Cytogenetic analysis of Trichomycterus areolatus, collected from the Tijeral and Huilma Rivers in southern Chile has shown a diploid chromosome number of 2n = 54, a fundamental number of FN = 106, and a karyotypic formula of 44m + 8sm + 2st. Intra-individual polymorphism of chromosome number (2n = 54, 55 and 56) in specimens from the Huilma River has also been documented, providing further evidence of the occurrence of this phenomenon in Trichomycterus. The karyotype exhibited large chromosome pairs: metacentric pairs 1 (relative length 7.54%), 2 (5.75%) and 3 (5.09%), submetacentric pair 23 (5.25%), and subtelocentic pair 27 (5.28%). Nuclear DNA content analysis showed an average value of 5.04 ± 1.09 pg/nucleus. This DNA content is higher than the mean... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Karyotype; Nuclear DNA content; Trichomycterus; Siluriformes. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572006000200014 |
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| Marques,Marilza Barbosa de Almeida; Moreira-Filho,Orlando; Garcia,Caroline; Margarido,Vladimir Pavan. |
| Two Siluriformes species endemic to the São Francisco River basin were characterized by conventional and differential cytogenetic analyses involving C-banding, Ag-nucleolar organizer region (NOR) and chromomycin A3 (CMA3) staining, and FISH (fluorescent in situ hybridization) with 18S and 5S rDNA probes. Conorhynchus conirostris presents a higher diploid number (2n = 60) than those detected in Pimelodidae representatives, whereas Lophiosilurus alexandri, with a karyotype of 2n = 54 chromosomes, presents a chromosomal constitution similar to that found in the family Pseudopimelodidae. Plesiomorphic characteristics such as single NORs at terminal positions are found in both species, as revealed by CMA3 and silver nitrate staining, and FISH with a 18S rDNA... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Incertae sedis; Pimelodidae; Pseudopimelodidae; RDNA; Siluriformes. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572008000200008 |
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| Diogo,Rui. |
| The cephalic and pectoral girdle structures of the heptapterin Hepapterus mustelinus (Nemuroglanis clade') are described and compared to those of two representatives of the other, more plesiomorphic, main heptapterin group, namely Goeldiella eques and Rhamdia guatemalensis ('basal clade'), as well as of several other catfishes, as the foundation for a discussion on the synapomorphies and phylogenetic relationships of the Heptapterinae. In addition to the five synapomorphies commonly referred in the literature, there is another potential Heptapterinae synapomorphy: the well-developed maxilla forming a completely closed, deep tube to enclose the base of the maxillary barbel. The subfamilies Pimelodinae, Heptapterinae and Pseudopimeodinae seem to form a... |
| Tipo: Journal article |
Palavras-chave: Catfish; Heptapterinae; Morphology; Phylogeny; Pimelodidae; Siluriformes. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022007000400011 |
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| Diogo,Rui. |
| The cephalic and pectoral girdle structures of Pangasius macronema are described and compared with those of another representative of the same genus, Pangasius larnaudii, and of representatives of the other pangasiid genus, Helicophagus leptorhynchus and Helicophagus typus, as well as of several other catfishes, as the foundation for a discussion of the synapomorphies and phylogenetic relationships of the Pangasiidae. The following two features could constitute Pangasiidae autapomorphies: 1) presence of prominent crest on the dorso-lateral surfaces of both the hyomandibulo-metapterygoid and the ento-ectopterygoid; 2) presence of a large, circular foramen between the anterodorsomedial surface of the extrascapular, the dorsomesial surface of the pterotic and... |
| Tipo: Journal article |
Palavras-chave: Catfish; Helicophagus; Pangasius; Pangasiidae synapomorphies; Morphology; Phylogeny; Siluriformes. |
| Ano: 2007 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022007000300001 |
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| Diogo,Rui. |
| As noted Gould in his recent and last book «The structure of evolutionary theory», discourses on the high importance and frequency of evolutionary trends have consumed a great part of the research on the history of clades. Although aware that natural selection theoretically yields adaptation to immediate environments, many authors defend such trends as generalised improvements somehow conferring advantages across most or all experienced environments. The high importance given to evolutionary trends is questioned by Gould, who considers that such a high importance given to such evolutionary trends bears no necessary relationship to the relative frequency or casual weight of these events in evolution, but mainly to a major bias: trends tell histories, and... |
| Tipo: Journal article |
Palavras-chave: Evolution; Morphology; Phylogeny; Siluriformes; Teleostei. |
| Ano: 2006 |
URL: http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0717-95022006000500016 |
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| de Pinna,Mário C. C.. |
| ABSTRACT A review is made of the impact of the landmark Ph. D. Thesis of Jonathan N. Baskin from 1973 on the development of the phylogenetics of catfishes and some of its main subgroups and on neotropical ichthyology in general. Baskin's work is the first to propose a hypothesis of relationships for loricarioid catfishes and for the family Trichomycteridae on the basis of explicit Hennigian principles. It is arguably also the first application of phylogenetic methods to any group of neotropical fishes. The hypotheses presented by Baskin covered the monophyly of Siluriformes, the monophyly and relationships of loricarioid families and the relationships of Trichomycteridae (including the monophyly of the family and the relationships among its constituent... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Candiru; Cladistics; Catfishes; Siluriformes; Trichomycteridae. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200219 |
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| Martins,Fernanda O.; Langeani,Francisco. |
| ABSTRACT Our analyses showed that the type series of Hisonotus notatus , type species of the genus, is mixed, composed by two different species. Based on that, we redescribe H. notatus with the designation of a lectotype, restricting the species to rio São João drainage and other small coastal drainages running to the Baía de Guanabara and to the Baía de Sepetiba in Rio de Janeiro State. We also describe a new species of Hisonotus from drainages of the rio Paraíba do Sul, Lagoa Feia, rio Macaé, and coastal rivers of Espírito Santo State, from rio Itabapoana to rio Doce basin. These two species are sister-taxa and can be distinguished by the number of plates in the mid-dorsal series. |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Biodiversity; Cascudinhos; Lectotype; Siluriformes; Taxonomy. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200218 |
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| Sazima,Ivan; Carvalho,Lucélia Nobre; Mendonça,Fernando Pereira; Zuanon,Jansen. |
| Resemblance to dead leaves is a well known type of camouflage recorded for several small vertebrates that dwell in the leaf and root litter on the ground. We present here instances of such resemblance in three species of nocturnal fishes (Siluriformes and Gymnotiformes) that spend the daytime among submersed root-tangle with leaf litter in Amazonian streams. All three species are very difficult to spot visually, due both to their shape and colors which blend with the substrate, as well as to the heterogeneous nature of their cover. Two species were recorded to lie on their sides, which adds to their resemblance to dead leaves. When disturbed, one species may drift like a waterlogged leaf, whereas another moves upwards the root-tangle, exposing its fore... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Crypsis; Leaf resemblance; Defence against predators; Siluriformes; Gymnotiformes. |
| Ano: 2006 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252006000100013 |
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| Freitas,Tiago Magalhães da Silva; Almeida,Vitor Hudson da Consolação; Montag,Luciano Fogaça de Assis; Rocha,Rossineide Martins da; Fontoura,Nelson Ferreira. |
| The aim of the present study was to evaluate the seasonal pattern of the gonadosomatic index (GSI), condition factor (K), and sex ratio in the catfish Auchenipterichthys longimanus (Siluriformes: Auchenipteridae) as an approach to identify its reproductive period. A total of 589 A. longimanus specimens (251 males and 338 females) were captured in the rivers of the Caxiuanã National Forest, in the Brazilian state of Pará, between July, 2008 and July, 2009. Among the male specimens, 171 were classified as adults and 80 as juveniles, while there were 249 adults and 89 juvenile females. Using a sinusoidal equation, analysis of the GSI revealed a reproductive asynchrony between the genders, with males attaining their highest GSI values in January, while females... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Auchenipterichthys longimanus; Hydrological seasons; Reproduction; Siluriformes. |
| Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000400015 |
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| Zawadzki,Cláudio H.; Weber,Claude; Pavanelli,Carla S.. |
| Two new species of Hypostomus Lacépède (Teleostei: Loricariidae) from the rio Paranaíba and rio Grande basins, both in the upper rio Paraná basin, central Brazil, are described herein. One of them is distinguished from all congeners, except H. albopunctatus, by having the pectoral-fin spine length equal to or smaller than the pelvic-fin spine. From H. albopunctatus, it is distinguished by having round dark spots (vs. pale) on body and fins. The second species is distinguished from all congeners, except H. multidens and H. ternetzi, by having more than 115 teeth (vs. less than 109) per ramus on dentary and premaxilla. It is distinguished most readily from H. ternetzi by having teeth with two symmetrical (vs. asymmetrical) cusps. It is distinguished from H.... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Catfishes; Neotropical fishes; Siluriformes; Taxonomy. |
| Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000300013 |
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| Registros recuperados: 45 | |
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