title: Structural analysis of embryogenesis of Leiarius marmoratus (Siluriformes: Pimelodidae).
abstract: Embryological studies in fish species are useful to the understanding of their biology and systematics. The available biological data in Leiarius marmoratus are scarce and additional information about its reproductive biology is needed, mainly because this species has been commercially exploited and used in production of hybrid lineages. In order to evaluate the temporal-morphological embryonic modifications in L. marmoratus, samples of nearly 200 embryos were collected at random at different stages of development, starting from fecundation (time zero). Embryos were fixed in modified Karnovsk's solution and 2.5% glutaraldehyde, processed and analysed under optic and electron microscopy. The incubation period of L. marmoratus was equal to 14.42 h at a mean temperature of 28.3 ± 0.07°C. The following stages of embryonic development were established: zygote, cleavage, gastrula, organogenesis and hatching. These stages were divided into phases, as follows: cleavage - phases of 2, 4, 8, 16, 32 and 64 cells and morula; gastrula - phases of 25, 50, 75 and 90% of epiboly and blastopore closure; and organogenesis - neurula, segmentation and pre-larval phases. The embryogenesis of L. marmoratus was typical of neotropical teleosteans, with peculiarities in species development.
authors.affiliation: Laboratório de Ictiologia Neotropical - L.I.NEO.,Depto de Biologia e Zootecnia,FEIS/UNESP - Universidade Estadual Paulista 'Julio de Mesquita Filho',Rua Monção,226 - Zona Norte,15385-000 - Ilha Solteira,São Paulo,Brazil.
authors.forename: Isângela Rodrigues
authors.initials: IR
authors.lastname: Oliveira-Almeida
authors.affiliation: Faculdade de Ciências Agrárias e Veterinárias,FCAV/UNESP. Via de Acesso Professor Paulo Donato Castellani,s/n,Rural,14884-900 Jaboticabal,São Paulo,Brazil.
authors.forename: Hellen
authors.initials: H
authors.lastname: Buzollo
authors.affiliation: Laboratório de Ictiologia Neotropical - L.I.NEO.,Depto de Biologia e Zootecnia,FEIS/UNESP - Universidade Estadual Paulista 'Julio de Mesquita Filho',Rua Monção,226 - Zona Norte,15385-000 - Ilha Solteira,São Paulo,Brazil.
authors.forename: Raphael da Silva
authors.initials: Rda S
authors.lastname: Costa
authors.affiliation: Laboratório de Ictiologia Neotropical - L.I.NEO.,Depto de Biologia e Zootecnia,FEIS/UNESP - Universidade Estadual Paulista 'Julio de Mesquita Filho',Rua Monção,226 - Zona Norte,15385-000 - Ilha Solteira,São Paulo,Brazil.
authors.forename: Rosicleire
authors.initials: R
authors.lastname: Veríssimo-Silveira
authors.affiliation: Laboratório de Genética de Peixes - LaGenPe,Depto. de Ciências Biológicas,UNESP- Universidade Estadual Paulista 'Julio de Mesquita Filho',Av. Eng. Luiz Edmundo Carrijo Coube,14-01,17033-360,Bauru,São Paulo,Brazil.
authors.forename: Fábio
authors.initials: F
authors.lastname: Porto-Foresti
authors.affiliation: Laboratório de Ictiologia Neotropical - L.I.NEO.,Depto de Biologia e Zootecnia,FEIS/UNESP - Universidade Estadual Paulista 'Julio de Mesquita Filho',Rua Monção,226 - Zona Norte,15385-000 - Ilha Solteira,São Paulo,Brazil.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Ninhaus-Silveira
mesh_terms: D000818:Animals; D036703:Blastula / Q000166:cytology / Q000648:ultrastructure; D002397:Catfishes / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000648:ultrastructure*; D047108:Embryonic Development / Q000502:physiology*; D005775:Gastrula / Q000166:cytology / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning / Q000379:methods; D009024:Morphogenesis / Q000502:physiology*; D009028:Morula / Q000166:cytology / Q000648:ultrastructure; D009865:Oocytes / Q000166:cytology / Q000648:ultrastructure; D038081:Organogenesis / Q000502:physiology*; D015053:Zygote / Q000166:cytology / Q000648:ultrastructure
keywords: Embryology; Morphology; Neotropical fish; Ontogenesis; Siluriform; Ultrastructure