title: Morphology of gametes, post-fertilization events and the effect of temperature on the embryonic development of Astyanax altiparanae (Teleostei, Characidae).
abstract: The aim of this study was to describe the morphology of gametes, post-fertilization events and subsequent temperature effects on the early developmental stages of the neotropical species Astyanax altiparanae. The sperm of this species presents a typical morphology of teleost sperm with a spherical head (diameter = 1.88 µm), midpiece (diameter = 0.75 µm) and a single flagellum (length = 18.67 µm). The extrusion of the second polar body and fusion of male and female pronucleus were reported for the first time in this species. Additionally, we observed the formation of the fertilization cone, which prevents polyspermic fertilization. Developmental stages at 22°C, 26°C and 30°C gave rise to fertilization rates at 91.12, 91.42 and 93.04% respectively. Hatching occurred at 25 hpf at 22°C, 16 hpf at 26°C and 11 hpf at 30°C and the hatching rates were 61.78%, 62.90% and 59.45%, respectively. At 22°C, the second polar body was extruded at ≈6 mpf and the male and female pronucleus fused at ≈10 mpf. This fundamental information is important for the field and opens up new possibilities in fish biotechnology, including micromanipulation and chromosome-set manipulation.
authors.affiliation: Aquaculture Center,São Paulo State University,Via de Acesso Prof. Paulo Donato Castellane s/n,Jaboticabal,SP 14884-900,Brazil.
authors.forename: Matheus Pereira
authors.initials: MP
authors.lastname: Dos Santos
authors.affiliation: Laboratory of Fish Biotechnology,National Center for Research and Conservation of Continental Fish,Chico Mendes Institute of Biodiversity Conservation,Rodovia Pref. Euberto Nemesio Pereira de Godoy,Pirassununga,SP 13630-970,Brazil.
authors.forename: George Shigueki
authors.initials: GS
authors.lastname: Yasui
authors.affiliation: Department of Veterinary Medicine-FZEA,University of São Paulo,Avenida Duque de Caxias Norte 225,Pirassununga,SP 13630-080,Brazil.
authors.forename: Pedro Luiz Porfírio
authors.initials: PL
authors.lastname: Xavier
authors.affiliation: Laboratory of Fish Biotechnology,National Center for Research and Conservation of Continental Fish,Chico Mendes Institute of Biodiversity Conservation,Rodovia Pref. Euberto Nemesio Pereira de Godoy,Pirassununga,SP 13630-970,Brazil.
authors.forename: Nadya Soares
authors.initials: NS
authors.lastname: de Macedo Adamov
authors.affiliation: Aquaculture Center,São Paulo State University,Via de Acesso Prof. Paulo Donato Castellane s/n,Jaboticabal,SP 14884-900,Brazil.
authors.forename: Nivaldo Ferreira
authors.initials: NF
authors.lastname: do Nascimento
authors.affiliation: Faculty of Fisheries Sciences,Hokkaido University,3-1-1 Minato-cho,041-8611,Hakodate,Japan.
authors.forename: Takafumi
authors.initials: T
authors.lastname: Fujimoto
authors.affiliation: Laboratory of Fish Biotechnology,National Center for Research and Conservation of Continental Fish,Chico Mendes Institute of Biodiversity Conservation,Rodovia Pref. Euberto Nemesio Pereira de Godoy,Pirassununga,SP 13630-970,Brazil.
authors.forename: José Augusto
authors.initials: JA
authors.lastname: Senhorini
authors.affiliation: Aquaculture Center,São Paulo State University,Via de Acesso Prof. Paulo Donato Castellane s/n,Jaboticabal,SP 14884-900,Brazil.
authors.forename: Laura Satiko Okada
authors.initials: LS
authors.lastname: Nakaghi
mesh_terms: D000818:Animals; D001757:Blastomeres / Q000166:cytology; D036703:Blastula / Q000166:cytology / Q000254:growth & development; D060126:Characidae / Q000196:embryology*; D004625:Embryo, Nonmammalian; D005260:Female; D005306:Fertilization; D005307:Fertilization in Vitro; D005775:Gastrula / Q000166:cytology / Q000254:growth & development; D008297:Male; D008855:Microscopy, Electron, Scanning; D009865:Oocytes / Q000648:ultrastructure; D038081:Organogenesis; D013094:Spermatozoa / Q000648:ultrastructure*; D013696:Temperature
keywords: Embryo; Fish; Oocyte; Reproduction; Spermatozoa