Evidence for the presence of the Portuguese oyster, Crassostrea angulata, in northern China.ABSTRACT The Pacific oyster Pacific oyster n. An oyster (Crassostrea gigas) cultured in the United States and Europe, having a scalloped shell and a fruity flavor. Also called Portuguese oyster. , Crassostrea gigas (Thunberg), and the Portuguese oyster Portuguese oyster Crassostrea angulata, C. pipas. , C. angulata (Lamarck), are two closely related taxa taxa: see taxon. . Although these two taxa were both introduced from Asia into Europe, one (C. gigas) was voluntarily introduced in the early 1970s, whereas the other (C. angulata) was presumed to be present in Europe for at least four centuries, but nearly disappeared because of disease. Few C. angulata populations remained in southern Portugal, Spain and Morocco and their putative origin was traced in Taiwan. The present paper reports evidence for its presence in Northern China. We reanalyzed recently published mitochondrial mitochondrial pertaining to mitochondria. mitochondrial RNAs a unique set of tRNAs, mRNAs, rRNAs, transcribed from mitochondrial DNA by a mitochondrial-specific RNA polymerase, that account for about 4% of the total cell RNA that cytochrome oxidase cytochrome oxidase n. An oxidizing enzyme containing iron and a porphyrin, found in mitochondria and important in cell respiration as an agent of electron transfer from certain cytochrome molecules to oxygen molecules. C subunit I (COI) sequence data from presumed Dalianwan oysters (C. talienwhanensis) and compared them with those of C. gigas and C. angulata. Additionally, two new C. angulata haplotypes from Portugal were identified. The results clearly showed that some of the C. talienwhanensis sequences cluster with C. angulata sequences. The relative divergence between C. gigas, C. angulata, and C. talienwhanensis haplotypes indicated that C. angulata-like oysters are present in northern China. This opens new perspectives in terms of genetic resources and population genetics Population genetics The study of both experimental and theoretical consequences of mendelian heredity on the population level, in contradistinction to classical genetics which deals with the offspring of specified parents on the familial level. of C. gigas and C. angulata, two oyster species of aquacultural importance. KEY WORDS: cupped oysters, Crassostrea angulata, Crassostrea gigas, Crassostrea talienwhanensis, cytochrome oxidase C subunit I gene, phylogeography INTRODUCTION The phenotypic plasticity The ability of an organism with a given genotype to change its phenotype in response to changes in the environment is called phenotypic plasticity. Such plasticity in some cases expresses as several highly morphologically distinct results; in other cases, a continuous norm of of oysters and their wide range of distribution are known to have led to numerous taxonomic misclassification or redundancy in species names. However, during the last decade, molecular tools have contributed in highlighting and resolving several of these cases. For example, Anderson and Adlard (1994) proposed that Saccostrea commercialis Saccostrea commercialis farmed bivalve; called also Sydney rock oyster. See Table 23. and S. glomerata should be regarded as synonymous taxa based on rDNA internal transcribed spacer ITS (for internal transcribed spacer) refers to a piece of non-functional RNA situated between structural ribosomal RNAs (rRNA) on a common precursor transcript. Read from 5' to 3', this polycistronic rRNA precursor transcript contains the 5' external transcribed sequence (5' ETS), sequence data. More recently, Kenchington et al. (2002) suggested that Ostrea edulis and O. angasi are conspeciflc. In addition, O'Foighil et al. (1999) confirmed the transoceanic range (New Zealand New Zealand (zē`lənd), island country (2005 est. pop. 4,035,000), 104,454 sq mi (270,534 sq km), in the S Pacific Ocean, over 1,000 mi (1,600 km) SE of Australia. The capital is Wellington; the largest city and leading port is Auckland. and Chile) of O. chilensis using mitochondrial COI sequence data and proposed that dispersal by rafting was the most likely explanation for this distribution. Similarly, the mangrove mangrove, large tropical evergreen tree, genus Rhizophora, that grows on muddy tidal flats and along protected ocean shorelines. Mangroves are most abundant in tropical Asia, Africa, and the islands of the SW Pacific. oyster Crassostrea gasar was shown to be present not only along the coasts of Western Africa but also along the Atlantic coasts of South America South America, fourth largest continent (1991 est. pop. 299,150,000), c.6,880,000 sq mi (17,819,000 sq km), the southern of the two continents of the Western Hemisphere. where some specimens had been wrongly described as C. rhizophorae (Lapegue et al. 2002). In this context, the relative taxonomic status of the Portuguese oyster, C. angulata, and the Pacific oyster, C. gigas, may be considered as a case study. C. gigas and C. angulata were classified as two different species by Thunberg in 1793 and Lamarck in 1819, respectively. This classification was chiefly due to apparently separated geographical distribution the natural arrangements of animals and plants in particular regions or districts. See under Distribution. See also: Distribution Geographic of the two species, because C. angulata was described in Europe and C. gigas in Asia. However, following morphologic comparison (Ranson 1948), experimental hybridization hybridization /hy·brid·iza·tion/ (hi?brid-i-za´shun) 1. crossbreeding; the act or process of producing hybrids. 2. molecular hybridization 3. (reviewed by Gaffney & Allen 1993, Huvet et al. 2001, Huvet et al. 2002) and allozyme data (Mathers et al. 1974, Buroker et al. 1979, Mattiucci & Villani 1983), the authors concluded that there was only a single species, grouping Portuguese and Pacific oysters. Yet, significant phenotypic differences between the two taxa were observed, in terms of production yield (Bougrier et al. 1986, Heral 1986, Parache 1989, Soletchnick et al. 2002), and eco-physiologic characteristics (His 1972, Goulletquer et al. 1999, Haure et al. 2003). Furthermore, differences have now been observed (1) from karyotype analyses (Leitao et al. 1999b) although these two taxa exhibited a close genetic similarity in comparison with other cupped oyster species (Leitao et al. 1999a); (2) in the genetics of the two taxa based on the mitochondrial COI gene (Boudry et al. 1998, O'Foighil et al. 1998) and nuclear microsatellites (Huvet et al. 2000). The introduction of the Pacific oyster was relatively well documented because it was a recent voluntary introduction. Hence, the introduction of C. gigas from Japan into Europe was made in the early 1970s to replace the Portuguese oyster in the shellfish industry (Grizel & Heral 1991) that nearly disappeared probably due to an iridoviral disease (Comps 1969). As indicated by its common name, the Portuguese oyster, was believed to originate from Portugal or at least southern Europe Southern Europe or sometimes Mediterranean Europe is a region of the European continent. There is no clear definition of the term which can vary depending on whether geographic, cultural, linguistic or historical factors are taken into account. . However, results from nuclear and mitochondrial DNA Mitochondrial DNA (mtDNA) is the DNA located in organelles called mitochondria. Most other DNA present in eukaryotic organisms is found in the cell nucleus. Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived from the studies (Boudry et al. 1998, O'Foighil et al. 1998, Huvet et al. 2000) suggested an explanation for the separated geographical distribution of these genetically closely-related taxa by supporting the hypothesis of the introduction of C. angulata from Asia (and more precisely Taiwan) to the Portuguese coast by merchant ships during the 16th century. Until now, no C. angulata specimens were observed in any other Asian location (see Lain et al. 2003, Boudry et al. 2003). China is the country with the largest C. gigas production (in 1997: Mainland China: 2.3 [10.sup.6] metric tonnes, Taiwan: 24 [10.sup.3] metric tonnes, Hong Kong Hong Kong (hŏng kŏng), Mandarin Xianggang, special administrative region of China, formerly a British crown colony (2005 est. pop. 6,899,000), land area 422 sq mi (1,092 sq km), adjacent to Guangdong prov. : 66 metric tonnes, according to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. FAO FAO, n See Food and Agriculture Organization. , 1999). However, Guo et al. reported in 1999 that it is not C. gigas, but another species, C. plicatula, that accounts for the main 50% to 60% of the production, C. ariakensis for 20% to 30% and C. gigas for only 10% to 20%. Qi (1989) also cited the Dalianwan oyster (C. talienwhanensis) as of commercial importance after the Zhe oyster (C. plicatula) and the Suminoe oyster (C. ariakensis) (Qi 1989). Many other different taxa have been reported along Chinese coasts and species identification is often uncertain. In Northern China, C. talienwhanensis, C. plicatula and C. gigas were considered as sibling species sibling species n. Any of two or more related species that are morphologically nearly identical but are incapable of producing fertile hybrids. (Liu & Dai 1998). In the East and South China, at least nine species have been described (Bernard et al. 1993). Recently, a new species was described in Hong Kong (Lain & Morton 2003, Boudry et al. 2003). Finally, a recent study based on mitochondrial DNA sequences showed that C. talienwhanensis specimens from Northern China were genetically close to C. gigas specimens which suggested that the Dalianwan and Pacific oysters belong to the same species (Yu et al. 2003). Similarly, their results suggested that C. plicatula and C. ariakensis are closely related. In the present paper, we compared DNA sequence DNA sequence Genetics The precise order of bases–A,T,G,C–in a segment of DNA, gene, chromosome, or an entire genome. See Base pair, Base sequence analysis, Chromosome, Gene, Genome. data of C. gigas, C. talienwhanensis, and C. angulata to establish their genetic relationships. To do so, we reanalyzed the mitochondrial COl sequence data of C. talienwhanensis specimens from Yu et al. (2003) and compared with those of known haplotypes from C. gigas, C. angulata (Boudry et al. 1998) and two newly identified C. angulata haplotypes. MATERIALS AND METHODS New Crassostrea angulata Sequence Data A total of 218 cupped oysters from Portugal were sampled in October of 2002 from 2 locations, 109 in the Sado estuary (Monte da Pedra site: 38[degrees]25'N, 8[degrees]39'W) and 109 in the Mira estuary (Roncao Velho site: 37[degrees]42'N, 8[degrees]44'W). DNA extraction of ethanol-preserved gill fragments was performed by a phenol/ chloroform chloroform (klôr`əfôrm) or trichloromethane (trī'klôrōmĕth`ān), CHCl3 method, as described by Moore (1993). A partial COI fragment was amplified using the primers and conditions detailed in Folmer et al. (1994). Polymorphism polymorphism, of minerals, property of crystallizing in two or more distinct forms. Calcium carbonate is dimorphous (two forms), crystallizing as calcite or aragonite. Titanium dioxide is trimorphous; its three forms are brookite, anatase (or octahedrite), and rutile. was first studied using restriction enzymes as described by Boudry et al. (1998). Some of these PCR PCR polymerase chain reaction. PCR abbr. polymerase chain reaction Polymerase chain reaction (PCR) products were sequenced as described by Boudry et al. (2003). All the novel sequences have been submitted to the EMBL EMBL European Molecular Biology Laboratory EMBL Eniwetok Marine Biological Laboratory nucleotide sequence database. DNA Sequence Analysis The COI sequences of the new haplotypes, together with some sequences already obtained for Crassostrea gigas and C. angulata (Accessions AJ553901, AJ553902, AJ553903, AJ553904, AJ553905; Boudry et al. 2003), C. virginica, C. ariakensis, and C. sikamea (Accessions AF152566, AF152569, AF152568; O'Foighil et al. 1998) and C. talienwhanensis (Yu et al. 2003) were aligned with CLUSTALW (Thompson et al. 1994). Pairwise sequence divergences between species were estimated with the DNADIST program in PHYLIP PHYLIP Phylogeny Inference Package (genetics software) (Felsenstein 1989) according to Kimura's two-parameter model (Kimura 1980). Phylogenetic phy·lo·ge·net·ic adj. 1. Of or relating to phylogeny or phylogenetics. 2. Relating to or based on evolutionary development or history. analyses were conducted using the program FITCH. Bootstrap See boot. (operating system, compiler) bootstrap - To load and initialise the operating system on a computer. Normally abbreviated to "boot". From the curious expression "to pull oneself up by one's bootstraps", one of the legendary feats of Baron von Munchhausen. analysis with 100 replicates was performed with the SEQBOOT and CONSENSE programs. RESULTS PCR-amplified fragments from the COI gene were obtained for 218 individuals from the newly sampled Portuguese populations. The PCR-RFLP PCR-RFLP Polymerase Chain Reaction–Restriction Fragment Length Polymorphism analysis detected 2 new haplotypes, which were called F and G here. Haplotype haplotype /hap·lo·type/ (-tip) the group of alleles of linked genes, e.g., the HLA complex, contributed by either parent; the haploid genetic constitution contributed by either parent. hap·lo·type n. G lacked a Sau3A restriction site restriction site n. A site in a DNA segment in which the bordering bases are vulnerable to restriction enzymes. Also called cleavage site. when compared with the others haplotypes of Crassostrea gigas and C. angulata described by Boudry et al. (1998). For haplotype F a new restriction site was observed using MseI when compared with the same haplotypes. These new haplotypes are rare, each one being present in one of the two populations: the frequency of haplotype F is 5% in Mira and the frequency of haplotype G is 2% in Sado. The COI sequences of haplotypes F and G, together with haplotype J--that had been described by Boudry et al. (2003), but not sequenced--were respectively registered as Accessions AY397685, AY397686, and AY455664. We compared the sequences of these haplotypes, F, G, and J, with those of haplotypes from C. gigas (haplotype C, D, and E; Boudry et al. 2003) C. angulata (haplotype A and B; Boudry et al. 2003), and C. talienwhanensis (haplotype talienw1, talienw2, talienw3, talienw4, and talienw5; Yu et al. 2003). The multiple alignment showed that haplotypes C and talien1 had exactly the same sequence. The distances computed after this alignment is presented in Table 1. The phylogenetic tree obtained from sequence divergence of the COI fragment according to Kimura's model (Kimura 1980) is given in Figure 1. The 12 haplotypes clustered into 2 groups (100% bootstrap P value) with a divergence varying from 2.2% to 3.7% depending the pairs of haplotypes being compared. One group encompassed the C. gigas haplotypes (C, D, and E) and the C. talienwhanensis haplotypes (talienw1, talienw2, and talienw3). The second group included the C. angulata haplotypes (A, B, J, F, and G) and the C. talienwhanensis haplotypes (talienw4 and talienw5). The nucleotide divergence within the first group varies from 0.2% to 0.5% and in the second group from 0.2% to 1.7%. C. sikamea and C. arienkensis, two other Asian cupped oysters species, respectively exhibited about 10% and 16% divergence with the C. gigas and C. angulata haplotypes. The American oyster, C. virginica, showed about 26% divergence with the C. gigas and C. angulata haplotypes and was considered as an outgroup. [FIGURE 1 OMITTED] DISCUSSION The geographic distribution of the closely related taxa Crassostrea gigas and C. angulata in southwestern Europe is now well documented, so is the genetic variability within the populations and the genetic differentiation between the populations. C. gigas was observed in northern Europe bordered by the headland of northern Spain (La Corogne) in the south. C. angulata was observed in southern Spain, Portugal, and Morocco (Boudry et al. 1998, Fabioux et al. 2002, Huvet et al. 2004). According to the grouping of the haplotypes observed here, haplotype F and G, detected in the new samples from the Mira and Sado Portuguese populations, can be considered as two new C. angulata haplotypes. This is confirmed by the divergence values that are of the order of those reported by Boudry et al. (2003): less than 0.5% for the C. gigas group compared with 0.2% to 0.5% in this study, and less than 1.1% for the C. angulata group compared with 0.2% to 1.7% in this study. When observing the results for the C. talienwhanensis haplotypes from Yu et al. (2003), talienw1 (identical to haplotype C), talienw2 and talienw3 are grouped with the C. gigas haplotypes, and talienw4 and talienw5 with the C. angulata haplotypes. Consequently, oysters of talienw1, talienw2 and talienw3 can be considered as C. gigas, as proposed by Yu et al. (2003), and the others (oysters of talienw4 and talienw5) can be considered as C. angulata. This partly confirms that the Dalianwan oyster, described by Zhang and Lou (1956), is another name for the Pacific oyster in China (Li & Qi 1994), but also supports that C. talienwhanensis being considered as C. angulata. After the evidence of the presence of C. angulata in Taiwan (Boudry et al. 1998), this species is now found existing in the northern China (Dalian, Liaoning province and Rongcheng, Shandong province) suggesting a broader Asian geographical distribution. Additionally, it should be noted that the cupped oysters specimens found in Hong-Kong (Lam et al. 2003, Boudry et al. 2003) and considered as belonging to a putative new taxa, cannot be considered as C. talienwhanensis. In total, 11 C. angulata COI haplotypes (A, B, and J from Boudry et al. 1998; angull, angul2, angul3, and angul4 from O'Foighil et al. 1998; talienw4 and talienw5 reanalysed from Yu et al. 2003; F and G in this study) and 5 C. gigas COI haplotypes (C, D, and E from Boudry et al. 1998; talienw1 (identical to haplotype C), talienw2, and talienw3 reanalysed from Yu et al. 2003) have now been described. Interestingly, using relatively equivalent amount of research on both taxa, the level of variability of C. gigas appears to be lower than that of C. angulata for the COI sequence. Furthermore, studies based on allozyme data by Buroker et al. (1979) also showed a high genetic variability in C. angulata, from Portuguese populations, relative to other Crassostrea species. More data are needed from other mitochondrial and nuclear markers, but this high genetic variability observed in C. angulata opens interesting perspectives for the development of conservation programs for this taxa in Europe. Consequently this also underlines the importance of C. angulata as a potentially useful genetic resource for C. gigas aquaculture aquaculture, the raising and harvesting of fresh- and saltwater plants and animals. The most economically important form of aquaculture is fish farming, an industry that accounts for an ever increasing share of world fisheries production. . Although the two 16S haplotypes described for the 10 C talienwhanensis individuals from Yu et al. (2003) study were each found in 2 different sampling locations (Dalian & Rongcheng), the 5 COI haplotypes (talienw1 to talienw5) distribution indicated that C gigas and C. angulata co-occur in the two sampled locations. Hence, one individual has the talienw1, one the talienw2, one the talienw3, four the talienw4, and three the talienw5 haplotypes. This result needs to be confirmed, because the number of samples (5 in each location) is low. It would be of particular interest to focus on the sympatric sym·pat·ric adj. Ecology Occupying the same or overlapping geographic areas without interbreeding. Used of populations of closely related species. status of these two taxa in this region as it was done in Southern Europe. In Portugal, there was evidence for hybridization between C. angulata and C. gigas in the wild where the two taxa are in contact due to recent transportation of C. gigas stocks for aquacultural production (Huvet et al. 2004). An extensive sampling protocol is clearly needed in Northern China to investigate this hybridization in the native region of these two taxa, and, more generally, their relative evolutionary history.
TABLE 1. Pairwise sequence divergences, for the mt COI DNA fragments
(C. angulata haplotypes are in bold).
Haplotype E Haplotype C Haplotype D talienw2
Haplotype E 0
Haplotype C 0,0036 0
Haplotype D 0,0055 0,0018 0
talienw2 0,0055 0,0018 0,0036 0
talienw3 0,0055 0,0018 0,0036 0,0036
Haplotype A# 0,0279 0,0241 0,0222 0,0260
Haplotype B# 0,0337 0,0299 0,0279 0,0318
Haplotype G# 0,0317 0,0279 0,0260 0,0299
Haplotype J# 0,0375 0,0337 0,0317 0,0356
Haplotype F# 0,0317 0,0279 0,0260 0,0298
talienw4 0,0298 0,0260 0,0279 0,0279
talienw5 0,0279 0,0241 0,0260 0,0260
C. sikannea 0,1051 0,1053 0,1031 0,1075
C. ariakensis 0,1623 0,1625 0,1650 0,1650
C. virginica 0,2590 0,2538 0,2512 0,2565
Haplotype
talienw3 Haplotype A# Haplotype B# G#
Haplotype E
Haplotype C
Haplotype D
talienw2
talienw3 0
Haplotype A# 0,0260 0
Haplotype B# 0,0318 0,0055 0
Haplotype G# 0,0299 0,0036 0,0055 0
Haplotype J# 0,0356 0,0091 0,0110 0,0091
Haplotype F# 0,0298 0,0110 0,0129 0,0110
talienw4 0,0279 0,0055 0,0073 0,0055
talienw5 0,0260 0,0036 0,0055 0,0036
C. sikannea 0,1075 0,1007 0,0986 0,1007
C. ariakensis 0,1601 0,1652 0,1725 0,1701
C. virginica 0,2512 0,2513 0,2567 0,2567
Haplotype J# Haplotype F# talienw4 talienw5
Haplotype E
Haplotype C
Haplotype D
talienw2
talienw3
Haplotype A#
Haplotype B#
Haplotype G#
Haplotype J# 0
Haplotype F# 0,0166 0
talienw4 0,0073 0,0129 0
talienw5 0,0091 0,0110 0,0018 0
C. sikannea 0,0984 0,1050 0,1029 0,1007
C. ariakensis 0,1723 0,1723 0,1676 0,1652
C. virginica 0,2569 0,2569 0,2594 0,2567
C. sikamea C. ariakensis C. virginica
Haplotype E
Haplotype C
Haplotype D
talienw2
talienw3
Haplotype A#
Haplotype B#
Haplotype G#
Haplotype J#
Haplotype F#
talienw4
talienw5
C. sikannea 0
C. ariakensis 0,1679 0
C. virginica 0,2627 0,2789 0
Note: C. angulata haplotypes are indicated with #.
talien1 and haplotype C have the same COI sequence.
ACKNOWLEDGMENT The authors thank H. McCombie for help with the English. This work was made possible by an FCT FCT Faculdade de Ciências e Tecnologia (Portuguese University) FCT Fundamentals of Computation Theory FCT Fundação para a Ciência e a Tecnologia (Portuguese Science and Technology Foundation) grant (SFRH/BD/8972/ 2002) and a Marie Curie Curie (kürē`), family of French scientists. Pierre Curie, 1859–1906, scientist, and his wife, Marie Sklodowska Curie, 1867–1934, chemist and physicist, b. Training fellowship (PLUDAMOR, QLK5-CT-2000-60036) to F. M. Batista. This work was partly supported by the Region Poitou-Charentes (Convention [N.sup.o]2001-RPC-A-212). LITERATURE CITED Anderson, T. J. & R. D. Adlard. 1994. Nucleotide-sequence of a rDNA internal transcribed spacer supports synonymy syn·on·y·my n. pl. syn·on·y·mies 1. The quality of being synonymous; equivalence of meaning. 2. Study and classification of synonyms. 3. 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Mitochondrial cytochrome oxidase I gene sequences support an Asian origin for the Portuguese oyster Crassostrea angulata. Mar. Biol. 131:497-503. O'Foighil, D., B. A. Marshall, T. J. Hilbish & M. A. Pino. 1999. Trans-Pacific range extension by rafting is inferred for the flat oyster Ostrea chilensis. Biol. Bull. 196:122-126. Parache, A. 1989. Growth performance of oyster Crassostrea angulata and Crassostrea gigas reared in Arcachon Bay between 1950 and 1986: First results. Haliotis 19:227-236. Qi, Z. 1989. Mollusc mollusc members of the phylum Mollusca, which comprises about 50,000 species. Includes snails, slugs and the aquatic molluscs—oysters, mussels, clams, cockles, arkshells, scallop, abalone, cuttlefish, squid. of Yellow Sea and Bohai Sea (in Chinese). Beijing: Agricultural Publishing House, pp. 176-180. Ranson, G. 1948. Ecologie et repartition re·par·ti·tion n. 1. Distribution; apportionment. 2. A partitioning again or in a different way. tr.v. re·par·ti·tioned, re·par·ti·tion·ing, re·par·ti·tions To partition again; redivide. geographique des Ostreides vivants. Rev. Sci. 86:469-473. Soletchnik, P., A. Huvet, O. Le Moine, D. Razet, P. Geairon, N. Faury, P. Goulletquer & P. Boudry. 2002. A comparative field study of growth, survival and reproduction of Crassostrea gigas, C. angulata and their hybrids. A quat. Living Res. 15:243-250. Thompson, J. D., D. G. Higgins & T. J. Gibson. 1994. CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment A multiple sequence alignment (MSA) is a sequence alignment of three or more biological sequences, generally protein, DNA, or RNA. In general, the input set of query sequences are assumed to have an evolutionary relationship by which they share a lineage and are descended from a through sequence weighting, position-specific gap penalties and weight matrix choice. Nucleic Acid nucleic acid, any of a group of organic substances found in the chromosomes of living cells and viruses that play a central role in the storage and replication of hereditary information and in the expression of this information through protein synthesis. Res. 22:4673-4680. Yu, Z., X. Kong, L. Zhang, X. Guo & J. Xiang. 2003. Taxonomic status of four Crassostrea oysters from China as inferred from mitochondrial DNA sequences. J. Shellfish Res. 22:31-38. Zhang, X. & Z. Lou. 1956. Studies on oysters in china. Acta Zool. Sin. 8:65-94. * SYLVIE LAPEGUE, (1) FREDERICO M. BATISTA, (2) SERGE HEURTEBISE, (1) ZINIU YU (3) AND PIERRE BOUDRY (1) * Corresponding author. E-mail: Sylvie.Lapegue@ifremer.fr (1) Laboratoire de Genetique et Pathologie, IFREMER, 17390 La Tremblade, France; (2) IPIMAR/CRIPsul, Av. 5 de Outubro, 8700-305, Olhao, Portugal; (3) College of fisheries College of Fisheries is located at the city of Mangalore which is headquarters of Dakshina Kannada district .The college offers courses in both graduate and undergraduate level. It is also involved in research of fisheries science. It has two campus within Mangalore. , Ocean University of China, Qingdao 266003, People's Republic of China |
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