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Registros recuperados: 1.204 | |
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Deprá,Gabriel de Carvalho; Ota,Renata Rúbia; Vitorino Júnior,Oscar Barroso; Ferreira,Katiane Mara. |
ABSTRACT Two new species from the upper rio Tocantins basin are described in Knodus based on the traditional definition of the genus. The new species are distinguished from other congeners by meristic and morphometric characters, such as the number of cusps in the premaxillary and dentary teeth, the number of scale series between dorsal-fin origin and lateral line, the orbital diameter and the body depth. With the two new species, the number of endemic species in the upper rio Tocantins basin upstream of the mouth of the rio Paranã, rises to 53 (89 to the confluence with rio Araguaia). The existence of a meristic character that changes through ontogeny (allomery), viz. the number of scale series between dorsal-fin origin and lateral line, was detected in... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Allochromy; Allomery; Endemism; Knodus breviceps; Secondary sexual characters. |
Ano: 2021 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252021000100208 |
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Benevides,Larissa J.; Nunes,José de Anchieta C. C.; Costa,Tiego L. A.; Sampaio,Cláudio L. S.. |
ABSTRACT When confronted by predators, prey need to make an economic decision between continuing their current activity or flee. Flight Initiation Distance (FID), the distance at which an organism begins to flee an approaching threat, has been used to indicate an animal's fearfulness level and a way to examine factors influencing escape decisions. Here we investigated how the FID of the barber surgeonfish, Acanthurus bahianus, responds to the presence of spearfishers in a fishing site in northeast Brazil. Specifically, we examined whether the FID was influenced by body and group size; by the heterogeneity of species in groups formation; and the distance to shelter. Significant differences in FID were observed with increasing body size. We found no... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Antipredator behaviour; Brazil; Flight initiation distance; Rocky reefs; Spearfishing. |
Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000100219 |
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L.,María Doris Escobar; Farias,Izeni P.; B.,Donald C. Taphorn; Landines,Miguel; Hrbek,Tomas. |
The arowanas, fishes of Gondwanan origin, are represented in South America by the genus Osteoglossum. All species were initially reported as being exclusive to the Amazon region, with O. ferreirai restricted to the Negro River basin and O. bicirrhosum to the Amazon and Essequibo Rivers basin. Starting in the mid 1970's it was reported that O. ferreirai also occurs in the Orinoco River basin. In all regions the arowanas assumed significant socio-economic importance due to their popularity in the international ornamental fish trade, leading to over-exploitation of both species in some areas. The Orinoco populations are particularly heavily exploited, and thus conservation and management measures are needed. Both depend on the clarification of taxonomic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aruana; Biological introduction; Black arowana; Silver arowana. |
Ano: 2013 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252013000200335 |
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Chierichetti,Melisa A.; Scenna,Lorena B.; Giácomo,Edgardo E. Di; Ondarza,Paola M.; Figueroa,Daniel E.; Miglioranza,Karina S. B.. |
ABSTRACT The cockfish, Callorhinchus callorynchus, is a widely distributed holocephalan in the south-western Atlantic and an important resource for Argentinean fisheries. The reproductive characteristics of this species were studied in northern Argentinean coastal waters, where specimens arrive seasonally (winter-spring). Sexual dimorphism in maximum precaudal length (PCL) and total body mass (TM) was found, being females (PCL=630 mm; TM=3330 g; n=167) larger and heavier than males (PCL=482 mm; TM=1630 g; n=19). Maturity size for females was 466.22 mm PCL, representing 74% PCL of the largest female sampled. The mean number of ovarian follicles was 8.37 (± 4.84). The highest values of ovarian follicles diameter, gonadosomatic and oviducalsomatic indices... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Holocephalans; Maturity; Ovarian fecundity; Seasonality; South-western Atlantic. |
Ano: 2017 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252017000200203 |
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Teresa,Fabrício Barreto; Carvalho,Fernando Rogério. |
Following behaviour among Neotropical stream fishes have been scarcely reported. This type of feeding association was observed in a small stream in the upper rio Paraná system between the catfish, Aspidoras fuscoguttatus, acting as a nuclear species, and Knodus moenkhausii, Poecilia reticulata, and Astyanax altiparanae as follower species. Aspidoras fuscoguttatus individuals dug in the bottom during feeding, causing sediment suspension. Their followers picked food items in the "cloud" of suspended particles. Food items of sediment are no longer consumed by the catfish when in suspension, but are still available for K. moenkhausii, P. reticulata and A. altiparanae. Following behaviour is an alternative feeding tactic for these species, which reinforces the... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Aspidoras fuscoguttatus; Feeding strategies; Interspecific interaction; Following behaviour; Southeastern Brazil. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000100013 |
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Pires,Tiago H. S; Gibran,Fernando Z. |
The clingfish Gobiesox barbatulus shows nocturnal feeding activity, spending most part of the day stationary and adhered to the inferior part of stones. To feed, this species uses the sit-and-wait and particulate feeding tactics. It shows a carnivorous feeding habit mostly consuming small benthic crustaceans. It can move in two ways: (1) "stone-by-stone", sliding its ventral sucker disc across each stone and (2) "surf", when it takes advantage of the energy of the ebbing tide to quickly cross a distance up to four times its body length. Its reproductive season occurs between the end of spring and the beginning of summer, during which time it lays about 2,000 adhesive eggs of 1 mm each in a single layer under stones. It has more than one egg-laying session... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Activity; Microhabitat; Diet; Reproduction; Gobiesocidae. |
Ano: 2011 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252011000100022 |
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Farias,Izeni Pires; Leão,Adam; Almeida,Yane Santos; Verba,Júlia Tovar; Crossa M.,Marcelo; Honczaryk,Alexandre; Hrbek,Tomas. |
Arapaima gigas is one of the largest freshwater fishes of the world. It is socially monogamous, forming pairs, constructing a nest and providing parental care. We performed a paternity analysis under three scenarios in captive, semi-natural and natural areas using 10 microsatellite markers. As a positive control, we analyzed three pairs and their offspring isolated individually in artificial breeding ponds (a priori very high probability of monogamy). We then analyzed two samples of offspring from large artificial ponds with multiple adults but only one reproductive pair (a priori high probability of monogamy), two samples from semi-natural breeding station with multiple adults but only one reproductive pair (a priori high probability of monogamy), and a... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Mate choice; Microsatellites; Multiple paternity; Pirarucu; Polygamy. |
Ano: 2015 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252015000100195 |
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Thomas,Matthew R.; Py-Daniel,Lúcia H. Rapp. |
Three new species of Loricaria are described from large white- and black-water river channels of the Amazon basin of Brazil, the upper rio Negro drainage of southern Venezuela, and clear waters of the lower rio Tocantins. Loricaria spinulifera and L. pumila differ from other species of Loricaria by having unique patterns of abdominal plate development and hypertrophied odontodes forming conspicuous crests on dorsal surfaces of the head and predorsal plates. Both are small species of Loricaria, reaching sexual maturity at less than 120 mm SL, and exhibiting sexually dimorphic characters consistent with members of the L. cataphracta complex. Loricaria spinulifera differs from L. pumila in having a unique arrangement of buccal papillae and large thorn-like... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Neotropical; Taxonomy; Loricariinae; Calhamazon; Rio Negro. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000300011 |
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Secutti,Sandro; Trajano,Eleonora. |
The troglobitic armored catfish, Ancistrus cryptophthalmus (Loricariidae, Ancistrinae) is known from four caves in the São Domingos karst area, upper rio Tocantins basin, Central Brazil. These populations differ in general body shape and degree of reduction of eyes and of pigmentation. The small Passa Três population (around 1,000 individuals) presents the most reduced eyes, which are not externally visible in adults. A small group of Passa Três catfish, one male and three females, reproduced spontaneously thrice in laboratory, at the end of summertime in 2000, 2003 and 2004. Herein we describe the reproductive behavior during the 2003 event, as well as the early development of the 2003 and 2004 offsprings, with focus on body growth and ontogenetic... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Troglobitic catfish; Brazilian caves; Regressive evolution; Reproduction; Goiás State. |
Ano: 2009 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252009000300016 |
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Rocha,Marcelo Salles; Oliveira,Renildo Ribeiro de; Py-Daniel,Lúcia H. Rapp. |
A new species of Scoloplax is described from small tributaries of rio Aripuanã, rio Madeira drainage, Amazonas State, Brazil. The new species can be distinguished from its congeners by several morphological features, such as ventral midline plates with two longitudinal parallel rows of odontodes not covered by skin, pectoral and pelvic fins with all rays simple, unbranched, and mesethmoid with a thickened triangular anterior process. Implications of new records of S. dolicholophia from rio Japurá and other comparative features within the genus are discussed. |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Taxonomy; Neotropical; Systematics; Siluriformes. |
Ano: 2008 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252008000300005 |
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Bichuette,Maria Elina; Trajano,Eleonora. |
Rhamdia enfurnada, a new troglobitic (exclusively subterranean) catfish, is described from the Gruna do Enfurnado, Serra do Ramalho, southwestern Bahia State, middle São Francisco River basin. It differs from epigean congeners from the São Francisco River basin by the variable eye size, ranging from reduced to externally invisible (bilateral asymmetry in development of eyes is frequently observed), with a conspicuous orbital concavity (orbital diameter varying from 6.4 to 13.6% of head length in R. enfurnada and from 14.5 to 24.4% in the epigean species); by the dark pigmentation reduced due to a decrease in density of melanophores, and also variable. In comparison to other cave species, R. enfurnada presents a low degree of troglomorphism regarding... |
Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Subterranean catfishes; Rhamdia enfurnada; Bahia; São Francisco River basin; Taxonomy. |
Ano: 2005 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252005000400016 |
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Registros recuperados: 1.204 | |
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