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Aquaculture 2018
S e p t e m b e r 2 0 - 2 1 , 2 0 1 8
L i s b o n , P o r t u g a l
Page 26
Journal of
ISSN: 1307-234X
E u r o p e a n S u mm i t o n
Aquaculture, Fisheries
and Horticulture
Tambaqui is the main native fish species for the Brazilian aquaculture.
Studies of our group confirmed that under captivity the females are heavier
than males at harvesting weight of 3 kg. As the system of sex determination of
tambaqui remains unknown, we tested four different doses of 17β-oestradiol
administered for 6 weeks to produce monosex batches of tambaqui via the
direct method. To evaluate the phenotypic sex, we analysed histologically
135 fish (average 22/treatment) and to assess whether the fish meat of
treated tambaqui presented hormonal residues, an analytical method for
the determination of 17β-oestradiol residues in muscle was developed and
validated using high performance liquid chromatography coupled to tandem
mass spectrometry (LCMS/MS). The dose 120 mg kg-1 E2 of diet administered
from 14 mm length was the most effective treatment for tambaqui feminization
as no males were found in the group (85% females and 15% intersex). If one
considers that the intersex fish will not show precocious maturation (as males
do), this percentagewouldnot compromise the superiority of thegroup inweight
gain. Therefore, we consider that higher oestradiol doses are unnecessary
for aquaculture purposes. Regarding the food security of the technique, at a
quantification limit of 0.3 ng g -1, the muscle of treated tambaqui did not shown
detectable E2 residues. In conclusion, our results indicate that 120 mg kg-1 E2
of diet is sufficient to eliminate the males in tambaqui population, which would
increase almost 20% the profitability of the activity. Moreover, the technique is
safe for human consumption as no hormone residues are found in the meat
of treated fish. These data will greatly contribute for the native fish farming in
Brazil since it supports the development of new techniques for the tambaqui
industry.
Biography
Almeida F L has completed her PhD in 2009 from Utrecht
University (The Netherlands) and has developed her
Postdoctoral studies from the Institute of Marine Research of
Norway. She is now a permanent Researcher at the Brazilian
Agricultural Research Corporation. She has published 18 papers
in reputed journals and is currently leader of four research
projects, which includes international partnership, besides the
collaboration of different universities and research institutes
of Brazil. She has also been cooperating as a Reviewer from
reputed indexed scientific journals.
Production of monosex population in tambaqui ( Colossoma
macropomum)
Almeida F L1, Reis V R2 , Hoga C3 and Reyes F G R3
1Embrapa Amazonia Ocidental, Brazil
2Federal University of Amazonas (UFAM), Brazil
3University of Campinas, Brazil
Almeida F L et al., Journal of Volume:12
DOI: 10.21767/1307-234X-C1-002