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Revision of the South American freshwater genus Plagioscion (Teleostei, Perciformes, Sciaenidae)
(2005-11-15)
The South American freshwater sciaenid genus Plagioscion is reviewed. Five of the 15 nominal species assigned to the genus are considered to be valid: Plagioscion squamosissimus, widely distributed in Atlantic drainages ...
The karyotype of Scoloplax distolothrix (Teleostei: Siluriformes: Scoloplacidae)
(2006-09-01)
The karyotype of a fish species belonging to the family Scoloplacidae, Scoloplax distolothrix, is described for the first time. Cytogenetic studies showed that this species has 2n=50 chromosomes, 18 metacentrics, 18 ...
Karyotype variability in eight species of the subfamilies Loricariinae and Ancistrinae (Teleostei, Siluriformes, Loricariidae)
(2003-01-01)
Loricariidae is one of the largest fish families of the world, with about 650 species separated into six subfamilies. To date, cytogenetic data on only 56 species of this family are available. In the present study, the ...
Ultrastructure of spermiogenesis in Plagioscion squamosissimus (Teleostei, Perciformes, Sciaenidae)
(Churchill Livingstone, 1999-12-01)
Spermiogenesis in Plagioscion squamosissimus occurs in cysts. It involves a gradual differentiation process of spermatids that is characterized mainly by chromatin compaction in the nucleus and formation of the flagellum, ...
The ultrastructure of Sorubim lima (Teleostei, Siluriformes, Pimelodidae) spermatogenesis: premeiotic and meiotic periods
(Churchill Livingstone, 1999-12-01)
The ultrastructure of Sorubim lima spermatogenesis during the premeiotic and meiotic periods was studied. Our observations showed that the germ cells in the cysts are connected by cytoplasmic bridges and the mitotic and ...
Spermatogonia and spermatocyte ultrastructure in Hoplias malabaricus (Teleostei, Characiformes : Erythrinidae)
(Cambridge University Press, 2002-07-01)
The Hoplias malabaricus primary spermatogonium shows a large nucleus, central nucleolus, and low electron-dense cytoplasm containing nuages. In cysts, they undergo several mitotic divisions with incomplete cytokinesis, ...
Sperm ultrastructure and a new type of spermiogenesis in two species of Pimelodidae, with a comparative review of sperm ultrastructure in Siluriformes (Teleostei : Ostariophysi)
(Elsevier Gmbh, Urban & Fischer Verlag, 2008-01-01)
During spermiogenesis, the spermatids of the pimelodid species Pimelodus maculatus and Pseudoplatystoma fasciatum show a central flagellum development, no rotation of the nucleus, and no nuclear fossa formation, in contrast ...
Chromosome polymorphism in Astyanax fasciatus (Teleostei, Characidae). 2 – Chromosomal location of a satellite DNA
(Cytogenetic and Genome Research, 2018)