International Journal of Aquaculture, 2013, Vol.3, No.19, 105
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program in penaeids (Gilkolaei et al., 2011).
Contrary to
F. indicus,
in
P. semisulcatus
population
from the Tuticorin samples have high genetic variation
than other location; and the Ramanthapuram and
Pudukottai samples more diverged than Nagapattinam
and Chennai samples. This result indicated that the
P.semisulcatus
population diversity high towards
southern direction of south east coast of India. The
phylogenetic analysis produced 3distnict clade
such Tuticorin, Ramanathapuram-Pudukottai, and
Chennai-Nagapattinam, form these observation asserted
that 3 stock population in
P. semisulscatus
those are
Chennai-Nagapattinam, Puddukottai-Ramanathapuram,
and Turicorin. The genetic variation in a population of
P. semisulcatus
based on random amplified
polymorphic DNA (RAPD) analysis collected from
the Persian Gulf in Iran very weak genetic integrity
since the polymorphism percentage was 14.8%
(
Niamaimandi et al., 2010).
As for
P. monodon
population the pattern of number
and percentage of polymorjphism and phylogenetic
relationship as those of
F. indicus
.
The absence of
availability of
P. monodon
in Tuticorin indicate the
seasonal availability. The four population could be
split up into 3 stock such as Chennai, Nagapattinam
and Pudukkottai-Ramanathapuram. These finding also
implicit that the
P. monodon
highly diverged toward
north direction of south east coast of India as in the
case of
F.indicus
.
The RAPD analysis of broodstocks
of
P. monodon
from three different locales of Thailand
such as Satun-Trang, Trat, and Angsila, revealed, the
percentages of polymorphic bands were 48% and 45%
in Satun-Trang and Trat, respectively, suggesting a
high genetic variability of the two samples to be used
in selective breeding programs. Only 25%
polymorphic bands were found in the Angsila sample
(
Tassangkagon et al., 1997). Garcia et al. (1994)
reported a higher genetic variability in
L. vannamei
populations as polymorphic bands ranged from 39 to
77%.
In
P .monodon
32%
of the RAPD banding
patterns differences between Kochi and Chennai in
India (Vincent, 2003), but in 35% differences in the
present investigation.
In the persent study, the genetic diversity of all
penaeid population tested is moderate to high and
diversity based on the closer geographic distribution
such as Chennai, Nagapattinam, Pudukkottai,
Ramanathapuram and Tuticorin. Maggioni et al. (2003)
analyzed the population structure of
L. schmitti
occurring only in Brazil and reported that six
microsatellite loci were observed across eight
geographic locations and influenced by environmental
factors that exist across relatively small geographic
scales. The geographic differentiation have been
observed in penaeid (Aubert and Lightner, 2000; de la
Rosa –Velez et al., 2000, Gracia et al., 2001; Xu et al., 2001).
Phylogeographical subdivision of genetically distinct
varieties is not uncommon in
Penaeus
species such as
P. subtilis
in south America (Gusmao et al., 2000),
F.
merguiensis
in Thailand (Hualkasin et al., 2003) and
P.
monodon
in Thailand (Klinbunga et al., 1999;
Supungul et al., 2000) and in the Indowest Pacific
region (Duda and Palumbi, 1999; Benzie et al., 2002).
Tamilnadu is endowed with varied landscape such as
sandy beaches, beach ridges, backwaters, estuaries,
intertidal mud and sand flats, dunes, cliffs, beach
rocks, deltas, lagoons, mangrove forests and coral reef
ecosystems. The coast has been constantly undergoing
physical changes in the geological past and at present.
Many rivers bring considerable sediments, which
affect shore processes significantly. The seas having
algae, coral and other organisms accumulate in
varying nature of landforms and their disposition
along huge quantities to form reefs, which sometimes
extend the beaches and inland represents the
successive phase considerable distance offshore, and
also the position of transgression and regression of sea
level. Along development of these features are related
to the stand of the eastern coast of peninsular India,
narrow belts of sand the sea during their formation.
The Gulf of Mannar is a protected area of India
consisting of 21 small islands (islets) and adjacent
coral reefs in the Gulf of Mannar in the Indian Ocean
islands that lie along the 140 km stretch between
Tuticorin and Rameswaram (Ramanthapuram district).
Rameshwaram has several topographic expressions,
and imagery a geomorphic map of the Rameshwaram
which are the signatures of the interaction of marine
and Island. The evolution of coastal landforms aeolian
processes. These topographic features can be clearly
traced by integrating the landform serve as ecosystems,
which have components of distribution different
terrestrial, marine and atmospheric processes. Jackson
et al
.
(2001)
report that the marine larvae may move