Abstract
In order to evaluate aspects of reproductive biology of the "pequira" ( Bryconamericus stramineus) in the elevator of the Funil Dam - MG, fish capture was carried out from November 2008 to January 2009 and 317 individuals were collected. The mean standard length (SL) of the population was 4.96 cm and mean weight 1.80 g. The females had SL of 5.0 cm, while males had a SL of 4.6 cm. A sex ratio of 2.20: 1 (females: male) was observed. Our results show that 73% of the individuals analyzed were considered adults. The species presented low fecundity, mean of 470.9 oocytes per female and a mean diameter of 221.08 μm, with an increase in oocyte diameter over the evaluation period. The length of the first gonadal maturation was estimated at 5.0 cm. The results obtained in this work suggest that the reproductive cycle of the species occurs in the analyzed period. Although this species does not have migratory reproductive habits, the presence of adults in the reproductive stage was observed in the transposition area, which suggests a search for new environments for spawning.
Highlights
Pequira (Bryconamericus stramineus Eigenmann, 1908) is a South America native fish specie, with non-migratory habit and diurnal activity (Bizzotto et al, 2009), found in La Plata, and São Francisco rivers (Planquette et al, 1996; Lampert et al, 2007)
The difference among found lengths may be justified by the fact that the collection has been conducted at the pass system top and, to enter into the fish lift, the fish must overcome a gap between the downstream river and the lift channel entrance, and may restrict the smaller fish entry that can not overcome it
The occurrence of a greater females proportion compared to males in a fish population is reported by Mazzoni and Silva (2006) in Bryconamericus microcephalus, having found a sex ratio of 2.20:1
Summary
Pequira (Bryconamericus stramineus Eigenmann, 1908) is a South America native fish specie, with non-migratory habit and diurnal activity (Bizzotto et al, 2009), found in La Plata, and São Francisco rivers (Planquette et al, 1996; Lampert et al, 2007). Some examples were found by Godoy (1975), Nakatani (2001), and Winemiller (1989) for Bryconamericus beta and by Lampert et al (2004), who studied Bryconamericus iheringii in Vacacaí River in Rio Grande do Sul State (Brazil). Lampert et al (2007) observed that B. stramineus has split spawning and that the breeding season occurs between September and December, having a lower peak in February in the Ibicuí River, a tributary of Uruguay River Basin (Rio Grande do Sul, Brazil) Some examples were found by Godoy (1975), Nakatani (2001), and Winemiller (1989) for Bryconamericus beta and by Lampert et al (2004), who studied Bryconamericus iheringii in Vacacaí River in Rio Grande do Sul State (Brazil). Lampert et al (2007) observed that B. stramineus has split spawning and that the breeding season occurs between September and December, having a lower peak in February in the Ibicuí River, a tributary of Uruguay River Basin (Rio Grande do Sul, Brazil)
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
