Advanced search
Start date
Betweenand
Related content
(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Moments of induced spawning and embryonic development of Brycon amazonicus (Teleostei, Characidae)

Full text
Author(s):
Okada Nakaghi, Laura Satiko [1] ; Neumann, Erika [1] ; Faustino, Francine [1] ; Ribeiro Mendes, Jose Mario [1] ; de Braga, Francisco Manoel [1]
Total Authors: 5
Affiliation:
[1] Univ Estadual Paulista, Fac Filosofia Ciencias & Letras, Rio Claro, SP - Brazil
Total Affiliations: 1
Document type: Journal article
Source: ZYGOTE; v. 22, n. 4, p. 549-557, NOV 2014.
Web of Science Citations: 6
Abstract

Based on the economic and ecological relevance of Brycon amazonicus, the goal of this work was to describe the diameter of oocytes and eggs of this species, as well as the chronological embryonic development. The material was provided by Buriti fish farm, Nova Mutum - MT, Brazil. Samples of both oocytes and eggs were obtained from extrusion to hatching. The material was fixed and measured under stereomicroscope, and the samples were divided for light microscopy or scanning electron microscopy (SEM) analyses. At extrusion, the oocytes were bluish green. The frequency distribution of oocytes revealed that 87.7% of them ranged from 1.11-1.30 mm in diameter. During incubation, the total diameter of the eggs increased from 1.22 +/- 0.04 mm to 3.06 +/- 0.46 mm in the first 60 min post fertilization (PF), and growth ceased at 180 min PF. Between 10-30 s PF, most eggs were fertilized and fertilization cones were observed from 10 s onwards after gamete activation. The main fertilization events took place asynchronically and spermatozoa were visualized in the micropyle vestibule up to 90 s PF. The first cell was formed in the centre of the blastodisc 20 min PF. The morula stage was identified 2 h PF and, 3 h later, 70% of the yolk was covered by the blastoderm; the blastopore was almost entirely closed at 6 h PF. The cephalic and caudal regions of the embryo could be defined 8 h PF and hatching occurred after 13 h of embryonic development. The larvae hatched with undifferentiated organic systems and with a large yolk sac, free from swimming abilities or visual acuity. (AU)