The bluish sea star Linckia laevigata is purely marine and omnipresent on coral reefs throughout the tropical oceans of the universe, preponderantly in the Indo West Pacific Region and around the Northern portion of Australia ( Williams 2000 ) and is normally found in heavy figure all through the Philippine archipelago. It is characterized by house texture, presenting somewhat cannular, extended weaponries, and possessing short xanthous tubing pess. Number of weaponries scopes from 4-7 pieces of sub equal length frequently due to the regeneration, with reasonably stout and blunt terminals. Posses ‘ different coloring materials morph of which royal-blue or light-green royal blue is the most normally observed in unrecorded L. laevigata in the Pacific part ( Williams, 2000 ) . Mode of reproduction is sexual and with planktonic larval continuance of 22-28 yearss ( Yamagutchi 1977 ) . L. laevigata, an dweller of shallow reef countries exposed to the sunshine, on stones, dead coral or debris at deepnesss of 0 to 60 m. The sedentary grownup has limited dispersal potency ; it is slow traveling macrobenthos crawling in corals and bouldery crannies and migrating between reef spots for croping. However, holding a long larval phase is the advantageous mechanism of this asteroid for wider scope of distribution through inactive scattering with the H2O current and circulation. Frequently, population of L. laevigata in reef flats are made up of mature persons, and juvenile are seldom ascertained. Juvenile-to-adult transmutation is estimated to take topographic point in norm of about 2 old ages of age which connotes low turnover rate with a low degree of enlisting ( Yamagutchi 1977 ) .

The dispersal ability of the species coupled with the physical feature of the country defines recruitment success. This is one of the grounds for wide range dispersion which is thought to give rise to high cistron flow and low familial structuring between populations but high familial diverseness within populations ( Williams et al. 1993 ) . Having long planctonic larval phase and high dispersion potency, figure of L. laevigata surveies revealed high familial affinity among populations compared to other sedentary species ( Williams & A ; Benzie 1993 ; Juinio-Menez et Al 2003 ; Crandall et al. 2008 ) . However, other surveies reveals distinction on population meddled with physical factors such as hydrographic conditions, land multitudes and geological history ; the discontinuity of L. laevigata populations in Eastern Indian Ocean Central Indo-Malay Archipelago and Western Pacific ( Kochzius et al. 2009 ) and in Great Barrier Reef, West Australia and Fiji ( Williams & A ; Benzie 1997 ) . The same as through with Tridacna crocea in the Coral Triangle ( Kochzius & A ; Nuryanto 2008 ) and eastern seaside of the Philippines ( Ravago-Gotanco et al. 2007 ) . Past and present physical procedures clearly influence the structuring of the population of marine species. Fast fluxing pelagic currents, intricate current system of seascapelike that of the Indonesian flow through may supply a agency or be a barrier for larval transportation and/or isolation that will do high cistron flow or constriction of populations.

Eastern Visayas is characterized by local and major oceanographic conditions ; it is a frontier to the West Pacific Ocean in the eastern side where North Equatorial Current ( NEC ) bifurcates to Kuroshio to the North and Mindanao Current to the South ( Qu & A ; Lukas 2003 ) . Island of the country is delineated with different organic structures of H2O such as Samar Sea, Camotes Sea, Leyte Gulf and the passs of San Bernardino and San Juanico ( Fig. 1 ) . Coupled with dispersal ability of a species, familial construction of population in this country may hold been significantly influenced by these complex hydrographic features. Presence of Mindanao Current, an outgrowth of a large-scale pelagic current NEC that rush far down south of the Philippines may ease a high conveyance of plantonic propagules over the stretch of the eastern seaside which may do connectivity with northern and eastern Samar populations.

Previous surveies on population genetic sciences have shown suitableness of cytochrome oxidaze I ( COI ) cistron as a familial marker to infer information on connectivity form for array of Marine invertebrate species: the oyster Crassostrea argulata ( Foihil et al. 1998 ) , Tridacna crocea ( Kochzius & A ; Nuryanto 2008 ) , Periclimenes soror, Thyca cristallina and L. laevigata ( Crandall et al. 2008, Kochzius et Al. 2009, and Williams 2000 ) . To let some grade of comparing with predating surveies, this survey utilized partial sequences of mitochondrial COI to look into L. laevigata ‘s familial population construction and connectivity form in the islands of the Eastern Visayas ( Philippines ) correlating to the major physical procedures in the part.

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Calciferol: hesisArticlesThesisDocuspixMap.orig.tif

Figure. 1: Sample aggregation sites for Linckia laevigata in Eastern Visayas part of Philippines [ i.e. Northern Samar ; Western Samar ; Eastern Samar ; Leyte ] with the oceanographic characteristics


Sample aggregation. One centimeter arm amputation was done to avoid destructive sampling of 157 Linckia laevigata. Among the four described colour morph ( bluish, orange, green and violet ) merely blue was sampled and analyzed to forestall false belief consequence on familial distinction from this colour fluctuation ( Williams 2000 ) . Samples were collected from 5 Stationss in Eastern Visayas stand foring the Pacific side and the internal Waterss of the part: 1 in N. Samar, Eastern Samar 1, W. Samar 2 and 1 in Leyte ( Fig. 1 and Table 1 ) . Sampling Stationss were selected on the footing of land and H2O organic structure separation by 100s of kilometers. Collected samples were separately preserved with absolute ethyl alcohol and stored at 4A°c.

Deoxyribonucleic acid extraction, elaboration and sequencing. The Deoxyribonucleic acid from tissue samples were extracted utilizing the NucleoSpinA® Tissue extraction kit harmonizing to the protocol of the maker. Partial sequences of the mitochondrial cytochrome oxidase I cistron ( COI ) was used as familial marker. Amplification was conducted with the cosmopolitan DNA primers described by Folmer et Al. ( 1994 ) through PCR in a volume of 50I?l and contained 2I?l DNA templet, 10mM Tris-HCl ( pH 9 ) , 50mM KCl, 1.5mM MgCl2, 0.4I?M of each primer, 0.2 millimeter dNTPs, 2 I?l BSA ( 2 mg/ml ) and 1 U Taq polymerase following temperature profile 94A°C for 5 min, followed by 35 rhythms of1 min at 94A°C, 1.5 min at 45A°C and 1 min at 72A°C. Concluding extension was conducted at 72A°C for 5 min as described by Kochzius et al. ( 2009 ) . Purification of the PCR merchandises was done utilizing the QIAqiuck spin column PCR purification kit ( Qiagen ) following the prescribed protocol of the maker. Purified DNA strands will be sequenced utilizing the DyeDeoxy eradicator chemical science ( PE Biosystem ) and with an machine-controlled sequenator ( ABI PRISM 310 and 3100, Applied bio systems ) .

Familial diverseness. Sequence Navigator ( version 1.0.1 Applied Biosystems ) will be used to redact all sequences and consequence will be translated to amino acid utilizing the plan Bioedit ( version ) to see that functional mitochondrial Deoxyribonucleic acid was obtained and non atomic pseudogene. After which multiple alliance will be conducted with Clustal W through Bioedit package. Gene diverseness will be analyzed through computation of haplotype ( Nei 1987 as cited by Kochzius et Al. 2009 ) and nucleotide diverseness ( Nei & A ; Jin 1989 ) with the plan Arlequin ( hypertext transfer protocol: // ) .

Familial population construction and connectivity. To measure presence and significance of population construction informations will be analyzed utilizing analysis of molecular discrepancy ( AMOVA ; Excoffier et Al. 1992 ) and pairwise E?ST-values with the bundle Arlequin. Data set will be tested with a hierarchal analysis of molecular discrepancy to clarify familial discrepancy among population and within samples sing the geographics of the country. Programme TCS ( version 1.21 ; Clement et Al. 2000 as citation by Kochzius et Al. 2009 ) will be utilized for computation of haplotype web.

Table 1: Sample site in Eastern Visayas and figure of Linckia laevigata samples collected.



Date of Sampling

No. Of Samples


L. laevigata


Merida, Leyte




Marabut, Western Samar




Salcedo, Eastern Samar




San Jose, Northern Samar




Almagro, Western Samar







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