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Luiz Antônio Wanderley Peixoto - One of the best experts on this subject based on the ideXlab platform.
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New species of glass knifefish genus Eigenmannia (Gymnotiformes: Sternopygidae) with comments on the morphology and function of the enlarged cephalic lateral‐line canals of Sternopygidae
Journal of Fish Biology, 2020Co-Authors: Luiz Antônio Wanderley Peixoto, Murilo N. L. Pastana, Gustavo A. BallenAbstract:A new species of Eigenmannia is described from the Rio Parana (the Grande, Paranapanema and Tiete basins). This new species is distinguished from all congeners by colouration pattern, position of the mouth, relative depth of posterodorsal expansion on infraorbitals 1 + 2, number of teeth, osteological features, number of rows of scales above lateral line (LL) and morphometric data. Comments on the widened cephalic lateral-line canals of Sternopygidae and a dichotomous key to the species of Eigenmannia from the Rio Parana Basin are provided.
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a new species of Eigenmannia jordan evermann gymnotiformes sternopygidae from rio tapajos brazil with discussion on its species group and the myology within eigenmanniinae
PLOS ONE, 2019Co-Authors: Luiz Antônio Wanderley Peixoto, Willian M OharaAbstract:A new species of Eigenmannia is described from the rio Mutum, tributary of upper rio Juruena, rio Tapajos basin, Comodoro, Mato Grosso, Brazil. The new species is distinguished from all congeners by coloration pattern, position of the mouth, number of scales rows above lateral line, number of premaxillary and dentary teeth, number of precaudal vertebrae, orbital diameter, mouth width, relative depth of posterodorsal expansion on infraorbitals 1+2 and relative size of coronomeckelian bone. Comments on potentially useful characters in phylogenetic studies derived from musculature, discussion on Eigenmannia species-group and the first dichotomous key for Eigenmannia are provided.
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A new species of Eigenmannia Jordan & Evermann (Gymnotiformes: Sternopygidae) from rio Tapajós, Brazil, with discussion on its species group and the myology within Eigenmanniinae.
PLOS ONE, 2019Co-Authors: Luiz Antônio Wanderley Peixoto, Willian M OharaAbstract:A new species of Eigenmannia is described from the rio Mutum, tributary of upper rio Juruena, rio Tapajos basin, Comodoro, Mato Grosso, Brazil. The new species is distinguished from all congeners by coloration pattern, position of the mouth, number of scales rows above lateral line, number of premaxillary and dentary teeth, number of precaudal vertebrae, orbital diameter, mouth width, relative depth of posterodorsal expansion on infraorbitals 1+2 and relative size of coronomeckelian bone. Comments on potentially useful characters in phylogenetic studies derived from musculature, discussion on Eigenmannia species-group and the first dichotomous key for Eigenmannia are provided.
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A new species of Eigenmannia Jordan & Evermann (Teleostei: Gymnotiformes: Sternopygidae) from Río Ventuari, Venezuela
Zootaxa, 2018Co-Authors: Guilherme Moreira Dutra, Luiz Antônio Wanderley Peixoto, Carlos David De Santana, Wolmar Benjamin WosiackiAbstract:A new species of Eigenmannia is described from the Rio Ventuari, Rio Orinoco basin, Venezuela. It is distinguished from congeners by the presence of a bony dorsolateral flange on the dentary, the presence of teeth attached along a bony dorsolateral flange, and by the first premaxillary teeth attached to the anteroventral margin of the premaxilla. It is further distinguished from all remain congeners by a combination of characters, including a subterminal mouth, 99–107 scales along the lateral line until the end of the anal fin, and ii, 16–17 pectoral-fin rays.
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a new species of Eigenmannia jordan evermann teleostei gymnotiformes sternopygidae from rio ventuari venezuela
Zootaxa, 2018Co-Authors: Guilherme Moreira Dutra, Luiz Antônio Wanderley Peixoto, Carlos David De Santana, Wolmar Benjamin WosiackiAbstract:A new species of Eigenmannia is described from the Rio Ventuari, Rio Orinoco basin, Venezuela. It is distinguished from congeners by the presence of a bony dorsolateral flange on the dentary, the presence of teeth attached along a bony dorsolateral flange, and by the first premaxillary teeth attached to the anteroventral margin of the premaxilla. It is further distinguished from all remain congeners by a combination of characters, including a subterminal mouth, 99–107 scales along the lateral line until the end of the anal fin, and ii, 16–17 pectoral-fin rays.
Wolmar Benjamin Wosiacki - One of the best experts on this subject based on the ideXlab platform.
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a new species of Eigenmannia jordan evermann teleostei gymnotiformes sternopygidae from rio ventuari venezuela
Zootaxa, 2018Co-Authors: Guilherme Moreira Dutra, Luiz Antônio Wanderley Peixoto, Carlos David De Santana, Wolmar Benjamin WosiackiAbstract:A new species of Eigenmannia is described from the Rio Ventuari, Rio Orinoco basin, Venezuela. It is distinguished from congeners by the presence of a bony dorsolateral flange on the dentary, the presence of teeth attached along a bony dorsolateral flange, and by the first premaxillary teeth attached to the anteroventral margin of the premaxilla. It is further distinguished from all remain congeners by a combination of characters, including a subterminal mouth, 99–107 scales along the lateral line until the end of the anal fin, and ii, 16–17 pectoral-fin rays.
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A new species of Eigenmannia Jordan & Evermann (Teleostei: Gymnotiformes: Sternopygidae) from Río Ventuari, Venezuela
Zootaxa, 2018Co-Authors: Guilherme Moreira Dutra, Luiz Antônio Wanderley Peixoto, Carlos David De Santana, Wolmar Benjamin WosiackiAbstract:A new species of Eigenmannia is described from the Rio Ventuari, Rio Orinoco basin, Venezuela. It is distinguished from congeners by the presence of a bony dorsolateral flange on the dentary, the presence of teeth attached along a bony dorsolateral flange, and by the first premaxillary teeth attached to the anteroventral margin of the premaxilla. It is further distinguished from all remain congeners by a combination of characters, including a subterminal mouth, 99–107 scales along the lateral line until the end of the anal fin, and ii, 16–17 pectoral-fin rays.
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A New Species of the Glass Electric Knifefish Genus Eigenmannia Jordan and Evermann (Teleostei: Gymnotiformes: Sternopygidae) from Río Tuíra Basin, Panama
Copeia, 2017Co-Authors: Guilherme Moreira Dutra, Carlos David De Santana, Wolmar Benjamin WosiackiAbstract:A new species of Eigenmannia is described from the Rio Pucuro, Rio Tuira basin, Panama. It is diagnosed from all congeners by the position of the mouth, the color pattern, the number of anal-fin rays, the number of scales on lateral line, the number of scales rows above the lateral line, the number and arrangement of teeth on the dentary, the number of precaudal vertebrae, the relative depth of the posterodorsal expansion on infraorbitals 1+2, and the relative size of coronomeckelian bone. The new species is the first Eigenmannia described from Central American drainages, and the northernmost species of the genus. Una nueva especie de Eigenmannia es descrita del rio Pucuro, que pertenece a la cuenca del Rio Tuira, Panama. Esta diagnosticada de las demas especies del genero por la posicion de la boca, el padron de coloracion, el numero de radios de la aleta anal, el numero de escamas de la linea lateral, el numero de hileras de escamas arriba de la linea lateral, el numero y disposicion de los dientes en e...
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Eigenmannia besouro, a new species of the Eigenmannia trilineata species-group (Gymnotiformes: Sternopygidae) from the rio São Francisco basin, northeastern Brazil.
Zootaxa, 2016Co-Authors: Luiz Antônio Wanderley Peixoto, Wolmar Benjamin WosiackiAbstract:A new species of the Eigenmannia trilineata species-group is described from the rio Sao Francisco basin, Brazil. It is distinguished from closely related species by a unique set of characters, including a subterminal mouth, the presence of ii,13–14 pectoral-fin rays, a coronomeckelian bone that is 30% the length of Meckel’s cartilage, the specific pattern of the dentition of the premaxilla and dentary, and the more anterior origin of the superior midlateral stripe. Comments on species of the E. trilineata species-group are presented.
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the electric glass knifefishes of the Eigenmannia trilineata species group gymnotiformes sternopygidae monophyly and description of seven new species
Zoological Journal of the Linnean Society, 2015Co-Authors: Luiz Antônio Wanderley Peixoto, Guilherme Moreira Dutra, Wolmar Benjamin WosiackiAbstract:Eigenmannia trilineata Lopez and Castello, 1966 (Sternopygidae) was described from the Rio de La Plata basin and subsequently cited from most South American river basins. Questions about the limits of this species raise the possibility of the occurrence of undescribed species misidentified as E. trilineata. Herein we propose the Eigenmannia trilineata species group for species that share the presence of the superior medial stripe on the flank. This group comprises: Eigenmannia antonioi sp. nov., from the Rio Anapu, Rio Amazonas basin; Eigenmannia desantanai sp. nov., from the Rio Cuiaba, Rio Paraguay basin; Eigenmannia guairaca sp. nov., from the Riacho Agua do O, upper Rio Parana basin; Eigenmannia matintapereira sp. nov., from the Rio Uneiuxi and Rio Urubaxi, Rio Negro basin; Eigenmannia microstoma (Reinhardt, 1852), from the Rio Sao Francisco basin; Eigenmannia muirapinima sp. nov., from small tributaries of the Rio Amazonas; Eigenmannia pavulagem sp. nov., from the tributaries of Rio Capim, Rio Guama basin; E. trilineata, from the lower Rio Parana basin and Rio de La Plata basin; Eigenmannia vicentespelaea Triques, 1996, from Sao Vicente I and II caves, Rio Tocantins basin; and Eigenmannia waiwai sp. nov., from the Rio Trombetas basin. These species can be distinguished from each other by unique sets of meristics, morphometrics, osteological and colour pattern features. © 2015 The Linnean Society of London
Eric S Fortune - One of the best experts on this subject based on the ideXlab platform.
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Global Electrosensory Oscillations Enhance Directional Responses of Midbrain Neurons in Eigenmannia
Journal of Neurophysiology, 2006Co-Authors: John Ramcharitar, Eric W. Tan, Eric S FortuneAbstract:Eigenmannia, a genus of weakly electric fish, exhibits a specialized behavior known as the jamming avoidance response (JAR). The JAR results in a categorical difference between Eigenmannia that are...
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electrosensory interference in naturally occurring aggregates of a species of weakly electric fish Eigenmannia virescens
Behavioural Brain Research, 2005Co-Authors: Jonathan M Nizar, Erika Carrerag, Eric S FortuneAbstract:Abstract The detection and identification of behaviorally relevant signals in the presence of competing signals in the environment is a major challenge of animal sensory systems. In weakly electric fish such as Eigenmannia virescens , the interactions between the autogenous electric field and the electric fields of nearby conspecifics can have profound effects on the perception of other behaviorally relevant electrosensory information. To better understand the natural signals that the nervous system of Eigenmannia experiences during the processing of electrosensory information, we examined the electrosensory milieu of Eigenmannia in the wild and in the laboratory. Recordings of the electric fields of Eigenmannia were made in ‘black’ and ‘white’ waters near the Napo River in eastern Ecuador. Fourier analysis revealed that Eigenmannia typically experience the electric fields of three to five conspecifics during the day and night in each habitat. The median difference in electric organ discharge frequencies between nearby Eigenmannia during the day was 23 Hz in black water habitats, 41 Hz in white water, and 37 Hz at night in both habitats: these signals are known to activate tuberous electroreceptors and downstream CNS circuits. There was no correlation between the number of individual Eigenmannia detected at recording sites and electric organ discharge frequencies. Further, Eigenmannia apparently do not maximize the frequency differences between conspecifics. In laboratory studies fish were preferentially observed in aggregates of two fish or more. Aggregate sizes observed in the laboratory were similar to those in the wild.
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Roles for short-term synaptic plasticity in behavior
Journal of Physiology-paris, 2002Co-Authors: Eric S Fortune, Gary J RoseAbstract:Short-term synaptic plasticity is phylogenetically widespread in ascending sensory systems of vertebrate brains. Such plasticity is found at all levels of sensory processing, including in sensory cortices. The functional roles of this apparently ubiquitous short-term synaptic plasticity, however, are not well understood. Data obtained in midbrain electrosensory neurons of Eigenmannia suggest that this plasticity has at least two roles in sensory processing; enhancing low-pass temporal filtering and generating phase shifts used in processing moving sensory images. Short-term synaptic plasticity may serve similar roles in other sensory modalities, including vision. # 2003 Elsevier Ltd. All rights reserved.
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Roles for short-term synaptic plasticity in behavior.
Journal of physiology Paris, 2002Co-Authors: Eric S Fortune, Gary J RoseAbstract:Short-term synaptic plasticity is phylogenetically widespread in ascending sensory systems of vertebrate brains. Such plasticity is found at all levels of sensory processing, including in sensory cortices. The functional roles of this apparently ubiquitous short-term synaptic plasticity, however, are not well understood. Data obtained in midbrain electrosensory neurons of Eigenmannia suggest that this plasticity has at least two roles in sensory processing; enhancing low-pass temporal filtering and generating phase shifts used in processing moving sensory images. Short-term synaptic plasticity may serve similar roles in other sensory modalities, including vision.
Gary J Rose - One of the best experts on this subject based on the ideXlab platform.
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Roles for short-term synaptic plasticity in behavior
Journal of Physiology-paris, 2002Co-Authors: Eric S Fortune, Gary J RoseAbstract:Short-term synaptic plasticity is phylogenetically widespread in ascending sensory systems of vertebrate brains. Such plasticity is found at all levels of sensory processing, including in sensory cortices. The functional roles of this apparently ubiquitous short-term synaptic plasticity, however, are not well understood. Data obtained in midbrain electrosensory neurons of Eigenmannia suggest that this plasticity has at least two roles in sensory processing; enhancing low-pass temporal filtering and generating phase shifts used in processing moving sensory images. Short-term synaptic plasticity may serve similar roles in other sensory modalities, including vision. # 2003 Elsevier Ltd. All rights reserved.
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Roles for short-term synaptic plasticity in behavior.
Journal of physiology Paris, 2002Co-Authors: Eric S Fortune, Gary J RoseAbstract:Short-term synaptic plasticity is phylogenetically widespread in ascending sensory systems of vertebrate brains. Such plasticity is found at all levels of sensory processing, including in sensory cortices. The functional roles of this apparently ubiquitous short-term synaptic plasticity, however, are not well understood. Data obtained in midbrain electrosensory neurons of Eigenmannia suggest that this plasticity has at least two roles in sensory processing; enhancing low-pass temporal filtering and generating phase shifts used in processing moving sensory images. Short-term synaptic plasticity may serve similar roles in other sensory modalities, including vision.
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resolving competing theories for control of the jamming avoidance response the role of amplitude modulations in electric organ discharge decelerations
The Journal of Experimental Biology, 1999Co-Authors: Yumi Takizawa, Gary J Rose, Masashi KawasakiAbstract:The algorithm for the control of the jamming avoidance response (JAR) of Eigenmannia has been the subject of debate for over two decades. Two competing theories have been proposed to explain how fish determine the correct direction to shift their pacemaker frequency during jamming. One theory emphasizes the role of time-asymmetric beat envelopes, while the other emphasizes the role of amplitude- and phase-difference computations that arise from the differences in spatial geometry of the electric fields of neighboring fish. In repeating earlier experiments, we found that the decision to raise or lower the pacemaker frequency reliably above or below its resting level depends on the latter process, and that frequency deceleration responses to amplitude modulation appear to be sufficient to explain previous experimental results on which the former theory is based. Specifically, fish of the genus Eigenmannia show differential deceleration responses to asymmetric beat envelopes. The deceleration responses do not require phase modulation and show a sensitivity for amplitude modulation depth and selectivity for amplitude modulation rate comparable with that of JARs that are elicited when amplitude- and phase-difference information is available.
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Responses of electrosensory neurons in the torus semicircularis of Eigenmannia to complex beat stimuli: testing hypotheses of temporal filtering
Journal of Comparative Physiology A, 1994Co-Authors: Gary J Rose, Nathan Arthur Etter, Todd B. AlderAbstract:The weakly electric fish, Eigenmannia, changes its frequency of electric organ discharges (EODs) to increase the frequency difference between its EODs and those of a jamming neighbor. This jamming avoidance response is greatest for frequency differences (i.e., beat rates) of approximately 4 Hz and barely detectable at beat rates of 20 Hz. A neural correlate of this behavior is found in the torus semicircularis, where most neurons act as low-pass or band-pass filters over this range of beat rates.
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Differential distribution of ampullary and tuberous processing in the torus semicircularis of Eigenmannia
Journal of Comparative Physiology A, 1992Co-Authors: Gary J Rose, Susan J. CallAbstract:Gymnotiform electric fish sense low-and high frequency electric signals with ampullary and tuberous electroreceptors, respectively. We employed intracellular recording and labeling methods to investigate ampullary and tuberous information processing in laminae 1–5 of the dorsal torus semicircularis of Eigenmannia. Ampullary afferents arborized extensively in laminae 1–3 and, in some cases, lamina 7. Unlike tuberous afferents to the torus, ampullary afferents had numerous varicosities along their finest-diameter branches. Neurons that were primarily ampullary were found in lamina 3. Neurons primarily excited by tuberous stimuli were found in lamina 5 and, more rarely, in lamina 4. Cells that had dendrites in lamina 1–3 and 5 could be recruited by both ampullary and tuberous stimuli. These bimodal cells were found in lamina 4. During courtship, Eigenmannia produces interruptions of its electric organ discharges. These interruptions stimulate ampullary and tuberous receptors. The integration of ampullary and tuberous information may be important in the processing of these communication signals.
Cleusa Yoshiko Nagamachi - One of the best experts on this subject based on the ideXlab platform.
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chromosomes (Gymnotiformes: Sternopygidae)
2016Co-Authors: Danillo S. Silva, Julio Cesar Pieczarka, Jonathan S. Ready, Luiz A. W. Peixoto, Wolmar B. Wosiacki, Cleusa Yoshiko NagamachiAbstract:Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY se
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Karyotypic and morphological divergence between two cryptic species of Eigenmannia in the Amazon basin with a new occurrence of XX/XY sex chromosomes (Gymnotiformes: Sternopygidae)
Neotropical Ichthyology, 2015Co-Authors: Danillo Dos Santos Silva, Luiz Antônio Wanderley Peixoto, Wolmar Benjamin Wosiacki, Julio Cesar Pieczarka, Jonathan S. Ready, Cleusa Yoshiko NagamachiAbstract:Eigenmannia species are widely distributed in the Neotropics, with eight valid species currently recognized. Populations of Eigenmannia from three locations in the eastern Amazon were investigated using cytogenetic and morphological techniques, revealing two taxa designated here as Eigenmannia sp. "A" and Eigenmannia sp. "B". The species differ in three morphometric characters, two meristic characters, and one osteological character. Eigenmannia sp. "A" presents 2n = 34 (22 m/sm+12 st/a) and Eigenmannia sp. "B" presents 2n = 38 (14 m/sm+24st/a) and simple differentiated sex chromosomes of the type XX/XY. In both species the Constitutive Heterochromatin (CH) rich in A-T bases is distributed in the centromeric region of all chromosomes. Eigenmannia sp. "B" also presents CH blocks in the interstitial region of chromosome pairs 8, 9 and X which are positively stained with CMA3, indicating G-C rich regions. The NOR is located on the short arm of chromosome pair 17 of Eigenmannia sp. "A" and on the short arm of pair 14 of Eigenmannia sp. "B". FISH with rDNA probes hybridized to different-sized regions between homologs, suggesting heteromorphism. The differentiation of the X chromosome in Eigenmannia sp. "B" could be the result of amplification of repetitive DNA sequences.
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Cytogenetic studies in Eigenmannia virescens (Sternopygidae, Gymnotiformes) and new inferences on the origin of sex chromosomes in the Eigenmannia genus.
BMC Genetics, 2009Co-Authors: Danillo Dos Santos Silva, Julio Cesar Pieczarka, Susana Suely Rodrigues Milhomem, Cleusa Yoshiko NagamachiAbstract:Background Cytogenetic studies were carried out on samples of Eigenmannia virescens (Sternopygidae, Gymnotiformes) obtained from four river systems of the Eastern Amazon region (Para, Brazil).