International Journal of Aquaculture, 2015, Vol.5, No.23 1
-
12
9
have reported sufficient level of genetic variations
after 10 years of management and about 20 generations.
However those authors pointed out about the risk of
possible inbreeding. In our opinion, more work on
consanguinity levels should be done and the use of
other estimators would be profitable. Besides, although
a familiar selection program is perhaps not affordable
in our economic conditions, it would be the best
choice to combine classic and molecular genetics and
in this sense, research could widely contribute to
improve and increase production levels. A partial
solution could be for the moment to improve molecular
detection techniques, to expand the number of studied
loci
and the use of other indexes, such as the
mentioned effective population size.
Of course, for suitable yields in productions a strict
surveillance to nutrition, health and economic stimulation
to shrimp farmers and directives are important factors
always to take into a consideration. In that way,
researchers from The French Institute Of Marine
Science Research (IFREMER, from abbreviations in
French) had report controlled experiments with
different diets to raise offspring of the 25
th
generation
of
P. vannamei
in clear water to 40 g (Cuzon et al.,
2004). This is a punctual example on the importance
of other factors in the growth and survival of animals,
which definitely is the goal of the shrimp aquaculture
industry.
3 Materials and Methods
3.1 Productive markers record of several of the
descendants of the first introduced founder stock
in Cuba (S0-1).
The first founder stock (S0-1) of
P. vannamei
shrimps
was introduced into Cuba in post-larvae stage from
Shrimp Improvement System, in USA. After being
held for a period in quarantine post larvae were
planted in a 0.38 hm
2
pond at YAGUACAM Hatchery
Centre, in Cienfuegos, Cuba in at a stock density of
0.5 individuals/m
2
. A special diet was supplied to
achieve the status of parents and so on, becoming the
founder brood stock.
The semi intensive system is implemented in the four
existing farms throughout the country. Post larvae are
planted in commercial grow out ponds of around 8 –
10 hm
2
and at a stock density of 10 – 15 individuals/m
2
.
The pellet diet was supplied by Malta Cleyton from
Mexico. The analysis of the production performance
of commercial ponds was made from the first offspring
of these parental (S1-1). The Shrimp Culture Enterprise
(ECCAM in Spanish) provided the historical production
indicators records for the comparison of different
descendants of the first founder stock. Descendants
under study are show in Table 3. The two first and the
two last progenies of the first founder stock until
current moment of sampling were chosen for
productive analyzes.
Table 3 Evaluated progenies of the Founder stock of white
shrimp
P. vannamei
introduced into Cuba in 2003 and year of
culture in commercial ponds of each one
The data was organized in Microsoft Office Excel
2007 according to: final weight (g); final survival (%)
and yield (Kg/Hm
2
/cycle).
3.2 Stock nomenclature and sampling procedure
for genetic analysis.
Nomenclature and number of individuals from each
brood stock used for genetic analysis in this work is as
follows:
S0-1: 42 individuals of pure first introduction, previously
genetically characterized by Borrell et al., 2006.
S2-1: 21 individuals of the second generation of the so
called first introduction, previously genetically
characterized by Pérez-Beloborodova et al., 2012.
S9-1: and S10-1: 30 individuals respectively of the
ninth and tenth generations of the first introduction
genetically characterized in this work.
Note that from the first generation of the first
introduced stock (S1-1), genetic data was not obtained.
Instead of the first descendants, samples of the very
first stock (S0-1) were used to check genetic
parameters tendencies. Pleopods and/or muscle tissue
were randomly collected from adult shrimps at
YAGUACAM Hatchery Centre, Cienfuegos, Cuba.
The same quantity of males and females (1:1
proportion for sampling) was taken each time and
tissue pieces were maintained in vials with absolute
ethanol until used.
Founder stock
Descendants
Years of
culture
First introduction
(S0-1)
S1-1
S2-1
S9-1
S10-1
2004
2005
2012
2013
