Population structure of tropical abalone (Haliotis asinina) in coastal waters of Thailand determined using microsatellite analysis

Abstract: Three partial genomic libraries were constructed from genomic DNA of the tropical abalone (Haliotis asinina) that was digested with AluI, vortexed/sonicated, and digested with mixed enzyme (AluI, HincII, and RsaI). The libraries yielded 0.02%, 0.42%, and 1.46% positive microsatellite-containing clones, respectively. Eleven clones each of perfect, imperfect, and compound microsatellites were isolated. Ten primer pairs (CUHas1-CUHas10) were analyzed to evaluate their polymorphic level. The numbers of alleles per locus, observed heterozygosity (H 0 ), and expected heterozygosity (H e ) ranged from 3 to 26 alleles, and varied between 0.27 and 0.85 and between 0.24 and 0.93, respectively. Three microsatellite loci (CUHas2, CUHas3, and CUHas8) were further used for examination of genetic diversity and differentiation of natural H. asinina in coastal waters of Thailand. Genetic variabilities in terms of the effective number of alleles (n e ), H 0 , and H e were higher in 2 samples from the Gulf of Thailand (n e = 9.37, 7.66; H 0 = 0.62, 0.78; and H e = 0.87, 0.86) than those of one sample (n e = 6.04; H 0 = 0.58; and H e = 0.62) derived from the Andaman Sea. Assessment of genetic heterogeneity, including allele frequency comparison and pairwise F ST analysis, indicated interpopulational differentiation, between natural H. asinina from the Gulf of Thailand and that from the Andaman Sea (P < 0.0001)

HUFA levels in eggs of wild and cultured broodstock of <i>Macrobrachium rosenbergii</i>

The variation in egg quality, i.e. the potential of the egg to produce viable fry, is still a limiting factor in the commercial production of marine fish and crustacean fry. Better knowledge in this field would contribute to improved and especially more consistent hatchery outputs and to the development of more suitable broodstock diets. So far, objective criteria to evaluate egg quality are scarce. However, it is very likely that the nutrient composition of the eggs may be a good indicator for egg viability as it reflects the nutrient demands of the developing embryo and larva. Since (n-3) highly unsaturated fatty acids (HUFAs) have been identified as essential nutrients for the larvae of marine fish, shrimp and prawn a case study has been initiated with the giant freshwater prawn Macrobrachium rosenbergii to verify variations in (n-3) HUFA contents of eggs from wild and pond-reared broodstock

Highly unsaturated fatty acid requirements of <i>Penaeus monodon</i> postlarvae: an experimental approach based on <i>Artemia</i> enrichment

Penaeus monodon postlarvae (PL-5 to PL-15) were fed 5 different diets consisting of enriched Artemia nauplii with a specific n-3 HUFA content. Although the postlarvae grew well on an Artemia diet with low HUFA-content, the ability of PL-10 to endure osmotic stress remained low. Feeding Artemia enriched with medium levels of n-3 HUFA (sum n-3 HUFA =12,55mg/g DW) for 5 days considerably enhanced the resistance of PL-10 to osmotic stress and their survival recorded 5 days later. However, very high dietary levels of n-3 HUFA (31,2 mg/g DW) did not have any growth promoting effect, thus suggesting that an excessive supply of n-3 may not be beneficial to the shrimp. Our data demonstrate that subjecting postlarvae to reduced salinities for 2h provides a simple and rapid test for assaying the physiological condition of postlarval shrimp

Osmotic stress resistance as a quality diagnostic for penaeid postlarvae

Penaeus monodon postlarvae (PL-5) were reared for 10 days on Artemia nauplii enriched with various levels (2.65, 5.30, 12.60, 22.35 and 31.20 mg/g DW) of (n-3) highly unsaturated fatty acids (HUFA). On day 5 and 10, their resistance to osmotic shocks (transfer from 30 ppt to 0, 5, and 10 ppt diluted seawater) was analyzed. After 5 days, postlarvae fed Artemia containing 12.6 mg/g (n-3)HUFA or more had a significantly higher resistance (p<0.05) than controls. Five days later, no significant difference could be detected among the treatments. A positive correlation was found between the stress resistance of PL-10 and the survival recorded five days later in each tank (p<0.02). It is concluded that the resistance to osmotic stress is a valuable quality indicator for penaeid postlarvae. On the other hand, neither growth rate, nor their size can be considered adequate quality criteria

Genetic Diversity of Introduced (Pomacea canaliculata) and Native (PILA) Apple Snails in Thailand Revealed by Randomly Amplified Polymorphic DNA (RAPD) Analysis

Genetic diversity of the introduced golden apple snail, Pomacea canaliculata (Lamarck, 1822) and four native apple snails; Pila ampullacea (Linneaus, 1758), P. angelica (Annandale, 1920), P. pesmei (Morelet, 1889) and P. polita (Deshayes, 1830) in Thailand were studied by RAPD analysis. Two hundred and two polymorphic fragments (180-1500 bp in length) were generated across overall investigated samples (N = 254) using three informative primers (OPA07, OPB10 and UBC122). The percentages of polymorphic bands were 98.86%, 94.56%, 90.91%, 96.94% and 95.51% for Pomacea canaliculata, P. ampullacea, P. angelica, P. pesmei and P. polita, respectively. This indicated high genetic polymorphism of these taxa. A neighbor-joining tree between pairs of geographic samples within Pomacea canaliculata suggested a lack of phylogeography in this species. Moreover, candidate species-specific RAPD markers (pKUSCARPILA-F/R) found in Pomacea canaliculata (340 bp, OPB10), P. ampullcea (640 bp, OPA07), P. angelica (380 bp, UBC122) and Pila snails (430 bp, OPA07) were cloned and sequenced. Locus-specific primers were designed and tested against the target and nontarget species. A 259 bp SCAR marker was found in 95.0% of Pila apple snails (N = 163) but not in Pomacea canaliculata (N = 30). Therefore, this SCAR marker could be used in coupling with a Pomacea canaliculata-specific RAPD marker to unambiguously differentiate the introduced and native apple snails in Thailand

Genetic Diversity of Introduced (Pomacea canaliculata) and Native (PILA) Apple Snails in Thailand Revealed by Randomly Amplified Polymorphic DNA (RAPD) Analysis

Genetic diversity of the introduced golden apple snail, Pomacea canaliculata (Lamarck, 1822) and four native apple snails; Pila ampullacea (Linneaus, 1758), P. angelica (Annandale, 1920), P. pesmei (Morelet, 1889) and P. polita (Deshayes, 1830) in Thailand were studied by RAPD analysis. Two hundred and two polymorphic fragments (180-1500 bp in length) were generated across overall investigated samples (N = 254) using three informative primers (OPA07, OPB10 and UBC122). The percentages of polymorphic bands were 98.86%, 94.56%, 90.91%, 96.94% and 95.51% for Pomacea canaliculata, P. ampullacea, P. angelica, P. pesmei and P. polita, respectively. This indicated high genetic polymorphism of these taxa. A neighbor-joining tree between pairs of geographic samples within Pomacea canaliculata suggested a lack of phylogeography in this species. Moreover, candidate species-specific RAPD markers (pKUSCARPILA-F/R) found in Pomacea canaliculata (340 bp, OPB10), P. ampullcea (640 bp, OPA07), P. angelica (380 bp, UBC122) and Pila snails (430 bp, OPA07) were cloned and sequenced. Locus-specific primers were designed and tested against the target and nontarget species. A 259 bp SCAR marker was found in 95.0% of Pila apple snails (N = 163) but not in Pomacea canaliculata (N = 30). Therefore, this SCAR marker could be used in coupling with a Pomacea canaliculata-specific RAPD marker to unambiguously differentiate the introduced and native apple snails in Thailand