Scylla serrata ( Forskal ) is well-known being called as a clay crab, belongs to the household Portunidae and strongly related with Rhizophora mangle environment ( Gopurenko, 1999 ) . It is widely distributed and normally found in most estuarine, mangrove swamps, and shelter bay home ground of the coastal Waterss ( Macnae, 1968 ) .
Estampador ( 1949 ) has noted that the genus of Scylla has been considered monotypic, although the morphometric differences have found the being of more than one species ( Sugama, 1999 ) . There are four Scylla species has been recorded which is genetically and morphologically different ( Keenan, 1999 ) .
Although inhabit coastal Waterss largely in their life rhythm, female Scylla has been recorded to migrate offshore during engendering period ( Hill, 1994 ) . There are two accounts following this behavior ; the larvae might be intolerance to the low salt in estuarial home ground and to acquire more opportunity in larval dispersion.
Due to the fact that the larval phase took topographic point 3-4 hebdomads drifting in the unfastened sea Waterss ( Brick, 1974 ) , the plaktonic larval stage suggest high dispersion potency and possibility of extended cistron flow between population through inactive conveyance by ocean current ( Fratini, 2002 ) . However, Burton ( 1083 ) noted that the evident of dispersal capacities can non faithfully find the familial construction of natural population of Marine invertebrates.
There are two types of clay crab piscaries has been practised in Indonesia, viz. wild gaining control and civilization. Since the early 1980s, Scylla serrata has been recognized as a commercially of import crab species trade good in Indonesia. In recent twelvemonth, this piscaries have been developing due to market demand and high value. Harmonizing to Indonesian piscaries statistics, the crab export production reached 20.713 metric tons in 2008. Despite its importance in bring forthing income to the piscaries sector, nevertheless farther analyze about familial and connectivity of this species in Indonesia was missing.
This survey investigated the phylogeographic distribution of Scylla serrata in Indonesia and farther aimed to compare its familial population construction and connectivity form throughout Indo-West Pacific based on the old bing surveies.
Materials and methods
Specimens of Scylla serrata were purchased from 10 different local fish markets throughout Indonesia ; including from Sumatera, Java, Kalimantan and Nusa Tenggara Island. These geographic locations are shown in Figure 1. The sites were fundamentally selected based on their presence in the part and degree of geographical separation of wild clay crab angling countries. However, due to the clip bound and budget restraints, merely samples from 4 major islands ( 7 States ) were chosen in this survey. The sample aggregations were conducted between July to September 2010.
A individual cheliped portion from each sample specimen was removed and so conserved in 96 % ethyl alcohol before hive awaying it in a cool temperature until DNA extraction procedure. The figure of samples collected ( n ) were varied, runing from 11 to 20 persons.
Deoxyribonucleic acid extraction
A little musculus tissue from each cheliped specimen sample was removed and assorted with 500 µl 5 % Chelex, 25 µl 100 millimeter DTT ( Dithiothreitol ) and 20 µl Proteinase-K ( 20mg/ml ) . The suspension sample incorporating the musculus tissue was so gently homogenized by incubation machine ( Epperdorf Thermomixer Compact ) at 750 revolutions per minute at 54EsC and left overnight. The centrifugation 12.500 revolutions per minute of the sample was subsequently undertaken for 3 proceedingss by utilizing Eppendorf Epp Centrifuge Mini Spin 220U-022620151 to divide the supernatant from the chelex, followed by 95EsC warming for 5 proceedingss by Thermojet Equibio machine and eventually stored in icebox at -24EsC until needed for the following measure.
Mitochondrial cytochrome oxidase fractional monetary unit I ( COI ) cistron of 597-base brace ( bp ) section was amplified by polymerase concatenation reaction ( PCR ) utilizing two specific primers designed for insect and Scylla spp. sequences, viz. : mtd10 5′-T TGA TTT TTT GGT CAT CCA GAA GT-3 ‘ ( Roehrdanz, 1993 ) and C/N 2769 5’-TT AAG TCC TAG AAA ATG TTG RGG GA-3 ‘ ( Gopurenko et al. , 1999 ) which matching to 2172 and 2769 locations of Drosophila yakuba mtDNA sequence ( Clary and Wolstenholme, 1985 ) .
PCR elaborations were carried out in a MJ Research PTC-200 Thermo Cycler ( BC-MJPC200 ) consisted of 35 rhythms, which preceded with denaturation measure in 3 proceedingss and continued by the undermentioned rhythm profile: 94EsC denaturation for 30 seconds, 50EsC tempering for 30 seconds, 72EsC extension for 5 proceedingss, and completed with an extra extension measure for 5 proceedingss before storage in 10EsC. The PCR merchandises were so placed in a icebox of -24EsC.
The PCR merchandises were so screened in gel-electrophoresis in order to see the Deoxyribonucleic acid in the merchandise. Gene ruler TM 0.5 ?g/lane, 8 centimeter length gel was used as a Deoxyribonucleic acid ladder to detect the DNA presence. Electrophoresis was performed in a specific status of 250V for 35 to 40 proceedingss.
Analysis of molecular discrepancy ( AMOVA ) ( Excoffier et al. , 1992 ) were performed in this survey to measure familial distinction between population. The method introduced by Tajima and Nei ( 1984 ) was besides used in order to gauge FST indices by ciphering haplotypic frequences merely or included familial distances between haplotypes.
Significance degrees of pairwise FST were calculated by 10.000 substitution of haplotypes between population. This trial was performed under the hypothesis of no distinction between population occurred. While P value of the trial indicated the proportion of substitution which caused an FST value larger or equal to the ascertained one ( Fratini et al. , 2001 ) .
To prove the correlativity between familial distances with geographic distances, a Mantel trial ( 1967 ) was performed as applied in ARLEQUIN. Genetic distance was corresponded to the FST value calculated from haplotypic frequences from each pairwise comparing between vicinities.