This paper describes the peripheral mechanisms involved in signal processing of self and conspecificgenerated electric fields by the electric fish gymnotus carapo. Electrolocationcommunication discharges of the fish gymnotus. All structured data from the file and property namespaces is available under the creative commons cc0 license. Pdf revision of the polytypic electric fish gymnotus. These fish are nocturnal and mostly occur in quiet waters from deep rivers to swamps. For fish species distributed in both uplands and lowlands, it is unclear whether these rapids and waterfalls present population or biogeographical boundaries. Gymnotus are generally brownish with a banded pattern, but. A unique sex chromosome system in the knifefish gymnotus. Files are available under licenses specified on their description page. The banded knifefish gymnotus carapo is a species of gymniform knifefish native to a wide range of freshwater habitats in south america. Behavior of electric fish gymllotus carapo in a group. The carapo, so called in brasil, has a body about a foot in length, and not two inches in breadth, being in the shape of a knife. The new species is diagnosed by a unique combination of morphometric, meristic, and osteological traits, and a.
Gymnotus is a genus of neotropical freshwater fish in the family gymnotidae found widely in south america, central america and southern mexico 36th parallel south to 18th parallel north. The discharges were detected by electrodes immersed in a glass aquarium and were recorded on a conventional polygraph. A molecular phylogenetic analysis in gymnotus species. Not a good beginners species, due to its very respectable adult size, but it makes a stunning oddball addition to communities of larger fish. The anal fin, which is used to propel the fish backwards or forwards by an undulating motion is very long. Behavioral evidence for postpause reduced responsiveness. The family has about 40 valid species in two genera. We sought to test this using the geographically widespread banded. Fish biogeography in the lost world of the guiana shield. The diencephalic preglomerular complex of gymnotiform fish receives inputs from several sensory areas. The nakedback knifefishes are a family gymnotidae of knifefishes found only in fresh waters of central america and south america. In this study, we present the first chromosomal data in gymnotus bahianus from. Despite substantial alphataxonomic work in recent years, parts of the genus remain characterized by taxonomic.
Pdf revision of banded knifefishes of the gymnotus. By employing anterograde and retrograde tracing techniques, we studied the afferent and efferent connections of the dorsolateral area dorsal subdivision of the telencephalon with the preglomerular nuclei in the weakly electric fish, gymnotus carapo. Members of the species gymnotus carapo approach certain sources of electrical stimuli and, in a statistically significant number of instances, assume a stance parallel to the plane from which the stimuli originate. Electrophysiological properties of abdominal electrocytes. All four species showed single nucleolus organizing regions confirmed by results obtained through agnors and fish experiments using 18s rdna probes, which showed the nors localized on the first chromosome pair in gymnotus inaequilabiatus, gymnotus cf. Lateral electrocytes of the abdominal portion of the electric organ ofgymnotus carapo are innervated on both, rostral and caudal faces. The electric tissue extends along the fish body from the pectoral girdle to the tip of the tail, constituting a single, undivided organ.
Banded knifefishes gymnotus, gymnotidae comprise the most speciesrich, ecologically tolerant eurytopic, and geographically widespread genus of neotropical electric fishes gymnotiformes, with 40 valid species occupying most habitats and regions throughout the humid neotropics. The postpause changes described here may provide a new way to test current models of complex discharge generation in gymnotus carapo and illustrate the speed at which changes of an electric organ discharge can take place. This page was last edited on 14 september 2017, at 20. Gymnotus carapo linnaeus, taxonomic download help gymnotus carapo tsn notes. Unique sex chromosome system in the knifefish gymnotus. The greatest species richness is found in the amazon basin. The banded knife fish gymnotus carapo is among the most widely distributed, broadly adapted eurytopic, and phenotypically variable fish species in south america, with a. Pdf aggressive behavior and jamming avoidance response. Effects of in vitro exposure to mercury on male gonads and. Waveform generation of the electric organ discharge in. Aggressive behavior and jamming avoidance response in the weakly electric fish gymnotus carapo. The postpause changes described here may provide a new way to test current models of complex discharge generation in gymnotus carapo and illustrate the speed at.
A model is formulated that approximates the pattern of amplitude changes. Magnetic and electric characteristics of the electric fish. This study investigated the progressive effects of hgcl 2 in the testis and sperm of the tropical fish tuvira gymnotus carapo l. In both species, single adult males guard eggs and juveniles. Laming pr editor, brain mechanisms of behavior in lower vertebrates. The relation between the social behavior and the electrical emissions of gymnotus carapo is examined. Revision of the polytypic electric fish gymnotus carapo gymnotiformes, teleostei, with descriptions of seven subspecies.
It is the most widespread species of gymnotus, but it has frequently been confused with several relatives, including some found outside its range like the central america g. Carapus fasciatus 17741804 print iconographia zoologica special collections university of amsterdam uba01 iz15100107. Gymnotiformes were monitored to evaluate their ease and reliability as parameters to study sleep. All have organs adapted to the exploitation of bioelectricity. The density of tuberous electroreceptors was found to be. Gymnotus gymnotiformes, gymnotidae is the most diverse known neotropical electric knife fish genus.
Gymnotus choco, commonly known as the cuchillo spanish for knife, is an electric knifefish. Max westby the university of reading, whiteknights, reading, england four specimens of the electric fish, gymnotus carapo, were used in an experiment to investigate the soeial interactions of members of this speeies. Gymnotus carapo madeir ensis differs from a ll sympatric members of th e g. Multiple rearrangements in cryptic species of electric knifefish.
Nesting and paternal care in the weakly electric fish. Waveform generation in the weakly electric fish gymnotus. Multiple rearrangements in cryptic species of electric knifefish, gymnotus carapo gymnotidae, gymnotiformes revealed by chromosome painting. Smaller species, such as the yellowstriped, 30centimetre gymnotus carapo, are sometimes kept in home aquariums.
They are sometimes referred to by the english name banded knifefish, although this typically is reserved for the most widespread species, g. Electrical emissions in gymnotus carapo and their relation. Technical problems have hampered the study of sleep in teleosts. Waveform generation in the weakly electric fish gymnotus coropinae. Revision of banded knifefishes of the gymnotus carapo and g. However, taking into account the number, arrangement, and innervation of the electrocytes, it is possible to divide. The nerve supplies to rostral and caudal faces of each doubly innervated electrocyte arise from different metameric levels of the spinal cord and travel to their target electrocyte through separate nerve trunks. Pdf the banded knife fish gymnotus carapo is among the most.
Karyotypic diversity in four species of the genus gymnotus. Gymnotus has the ability to generate a pulsed electrostatic field from a specialized electric organ and detect electrostatic fields with electroreceptors. In this study we use for the first time, whole chromosome probes prepared by facs of the gymnotus carapo sensu strictu species, cytotype with. The systematic relationships among gymnotus species are controversial, particularly because of improper species description often identified as gymnotus carapo albert et al. The genus gymnotus has undergone considerable taxonomic revision in recent years, with over 20 new species being described since 1994, including several that were. Pdf revision of the polytypic electric fish gymnotus carapo. The banded knife fish gymnotus carapo is among the most widely distributed. Changes in electric organ discharge after pausing the. The banded knifefish, a brazilian fish, gymnotus carapo. The electric organ eo ofgymnotus carapo was studied using different neurohistological techniques including conventional electron microscopy.
Gymnotus carapo from savanna swamps on the caribbean island of trinidad. Pdf banded knifefishes gymnotus, gymnotidae comprise the most. Speciesspecific diversity of a fixed motor pattern. The banded knife fish gymnotus carapo is among the most widely distributed, broadly adapted eurytopic, and phenotypically variable fish species in south. The distribution of the different types of tuberous electroreceptor and the occurrence of particular electric field patterns close to the body of the fish were studied. Craig is already familiar with the journal, having been a monitoring editor since 2011. Population and phylogenetic analysis indicate a distinct split between upland and lowland populations, with those species in the highlands showing greater genetic similarity to populations from the amazon basin. Histopathology and metal concentrations in the testis were observed. Chromosomal evidence for a putative cryptic species in the. Electrolocationcommunication discharges of the fish. Gymnotus coropinae is a widely distributed species, occurring throughout most of the amazon and orinoco basins and the guyanas.
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