Results 171 to 180 of about 2,449 (227)

Sexual Dimorphism in the Electric Knifefish Sternarchogiton labiatus (Gymnotiformes: Apteronotidae) with a Hypermorphic Snout and Oral Jaws

Ichthyology & Herpetology, 2023
Secondary sexual dimorphism is relatively common in the ghost knifefishes (Gymnotiformes: Apteronotidae), with males of several species growing greatly elongated snouts (e.g., Compsaraia samueli, Parapteronotus hasemani), while others develop enlarged ...
Maxwell J. Bernt, Aaron H. Fronk, Kory M. Evans, James S. Albert   +3 more
semanticscholar   +1 more source

Postembryonic development of the cerebellum in gymnotiform fish

The Journal of Comparative Neurology, 1996
In contrast to adult mammals, adult teleost fish regularly generate new neurons and glial cells in many brain regions. A previous quantitative mapping of the proliferation zones in the brain of adult Apteronotus leptorhynchus (Teleostei, Gymnotiformes) has shown that 75% of all mitotically active cells are situated in the cerebellum (Zupanc and ...
Zupanc, G. ; https://orcid.org/0000-0001-8715-9994, Horschke, I., Ott, R., Rascher, G.   +3 more
openaire   +3 more sources

A Study on Force Generated by Gymnotiform Undulating Fin

2018 15th International Conference on Ubiquitous Robots (UR), 2018
Underwater vehicles inspired by the motion of fish can generate a highly efficient force. This paper considers the gymnotiform undulating fin which imitates the motion of South American black ghost knifefish. The equations of the force generated by both continuous and discontinuous sine wave are established.
Van Hien Nguyen, Canh An Tien Pham, Van Dong Nguyen, Dae Hwan Kim, Tan Tien Nguyen   +4 more
openaire   +1 more source

Molecular phylogeny of the ghost knifefishes (Gymnotiformes: Apteronotidae)

Molecular Phylogenetics and Evolution, 2019
Ghost knifefishes (Gymnotiformes: Apteronotidae) are weakly electric fishes that possess a high-frequency, neurogenic electric organ discharge. They are found throughout the humid Neotropics from Panama to Argentina and are most diverse and abundant in the channels of large lowland rivers.
Maxwell J, Bernt, Victor A, Tagliacollo, James S, Albert   +2 more
openaire   +2 more sources

Ontogeny and evolution of electric organs in gymnotiform fish

Journal of Physiology-Paris, 2008
In order to further our understanding of the evolution of electric organs in the Neotropical gymnotiform fish, we studied the ontogeny of the electric organs in eight species. In Eigenmannia virescens, Sternopygus macrurus, and Apteronotus leptorhynchus the earliest electrocytes are located between muscle fibres of the hypaxial muscle (Type A ...
F, Kirschbaum, H O, Schwassmann
openaire   +2 more sources

Morphological description and molecular characterization of Ancyracanthus electrophori n. sp. (Gnathostomatoidea: Gnathostomatidae): a new nematode parasitic in the electric eel Electrophorus varii (Gymnotiformes: Gymnotidae), from the Brazilian Amazon

Journal of Helminthology, 2023
A new species of Ancyracanthus, parasite of the electric eel Electrophorus varii, in the Brazilian Amazon, is described based on morphological and molecular characterization. Ancyracanthus electrophori n. sp.
L. R. Virgilio, A. Nogueira, R. M. Takemoto, M. D. Passere, A. D. de Oliveira, D. U. O. Meneguetti, M. A. Camargo, F. B. Pereira   +7 more
semanticscholar   +1 more source

Time-Comparator Neural Circuits of Gymnotiform Electric Fishes

Zoological Science, 2023
Weakly electric fish possess electrosensory neural systems that are dedicated to detect microsecond time differences between sensory signals. Many features of this timing system, such as electroreceptor encoding, time-locked responses, and time-comparator neural circuit, are shared by closely related as well as distantly related electric fishes.
openaire   +2 more sources

Comparative analysis reveals highly conserved satellite DNA landscapes in two sympatric Gymnotus (Teleostei, Gymnotiformes) electric knifefish.

Genome
Significant structural and evolutionary aspects associated with satellite DNAs (satDNAs) have been uncovered through the combination of cytogenetic and genomic analysis in a wide variety of organisms.
Silvana Melo Sviggum, C. Goes, Jhon Alex Dziechciarz Vidal, Rodrigo Zeni Dos Santos, M. E. Gisloti-Ribeiro, Leticia Masiero Desajacomo, Manuela Cândido de Mello Ferro, Claudio Oliveira, F. Porto-Foresti, M. Cioffi, Fausto Foresti, R. Utsunomia   +11 more
semanticscholar   +1 more source

Hydrodynamic optimality of balistiform and gymnotiform locomotion

European Journal of Computational Mechanics, 2017
Some groups of fish have evolved to generate propulsion using undulatory elongated fins while maintaining a relatively rigid body.
Brennan Sprinkle, Rahul Bale, Amneet Pal Singh Bhalla, Malcolm A. MacIver, Neelesh A. Patankar   +4 more
openaire   +1 more source

Biogeography and Breeding in Gymnotiformes from Uruguay

Environmental Biology of Fishes, 2003
This study was carried out in Uruguay (30–35°S), South America, with two complementary approaches. First, an extensive exploration of Uruguayan freshwaters allowed us to assess the distribution of the two major species of Gymnotiformes (out of 4) across sites.
Ana Silva, Laura Quintana, Matías Galeano, Pablo Errandonea   +3 more
openaire   +1 more source