identifier	taxonID	type	CVterm	format	language	title	description	additionalInformationURL	UsageTerms	rights	Owner	contributor	creator	bibliographicCitation
038E878C7B43FFA3DFB1FF03FC8BFAD5.text	038E878C7B43FFA3DFB1FF03FC8BFAD5.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Magallana belcheri (Sowerby II 1871)	<div><p>Magallana belcheri (Sowerby II, 1871)</p><p>(Fig. 4D–F)</p><p>Ostrea belcheri Sowerby II, 1871 (in 1870–1871): pl. 7, fig. 11 (type locality: “ Eastern Seas ?”).</p><p>Ostrea siamensis Mörch, 1853: 62 (type locality: “Singapuhra”)— nomen nudum.</p><p>Habitat. Not recorded in the wild in the upper gulf but included here for completeness.</p><p>Material examined. Site 2, Samaesan seafood market.</p><p>Published Gulf of Thailand records. Crassostrea belcheri (Sowerby II, 1871): Chaitiamwong et al. (1971); Aungtonya et al. (1999); Yoosukh &amp; Duangdee (1999); Day et al. (2000); Klinbunga et al. (2000, 2001, 2002, 2003, 2005); Yoosukh (2000); Bussarawit &amp; Simonsen (2006a); ONEP (2007); Nabhitabhata (2009); Bussarawit &amp; Cedhagen (2010; 2012); Phuwan et al. (2018); Trivej &amp; Kesjinda (2018); Ninwichian et al. (2021).</p><p>Geographic range. Native to Southeast Asia, with sequenced records from Pakistan, Myanmar, India, Thailand, Malaysia, Singapore, Vietnam, China, and Indonesia (Willan et al., 2021).</p><p>Remarks. This is an important aquaculture species on both sides of the Gulf of Thailand, particularly on the eastern side (Bussarawit &amp; Cedhagen, 2010; Trivej &amp; Kesjinda, 2018). Three specimens purchased in the Samaesan seafood market were field identified as Crassostrea sp. (Table 2). M. belcheri is known as the white scar oyster because its white adductor muscle scar differentiates it from M. bilineata, the black scar oyster with its black adductor muscle scar (see below).</p></div>	https://treatment.plazi.org/id/038E878C7B43FFA3DFB1FF03FC8BFAD5	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B43FFA3DFA5FA8FFBD3FC08.text	038E878C7B43FFA3DFA5FA8FFBD3FC08.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Magallana bilineata (Roding 1798)	<div><p>Magallana bilineata (Röding, 1798)</p><p>(Figs. 4A–C, 6A, B)</p><p>Ostrea bilineata Röding, 1798: 170 (type locality: not stated).</p><p>Ostrea lugubris Sowerby II, 1871 (in 1870–1871): pl. 26, fig. 63 (type locality: “North America?”).</p><p>Ostrea iredalei Faustino, 1932: 546, 547, pl. 1, figs. 1–4 (type locality: “ Navotas, Malabon, Parañaque, and other places on Manila Bay ”, Philippines).</p><p>Ostrea madrasensis Preston, 1916: 33–35, figs. 11, 11a (type locality: “ Ennur backwater, Madras ”, India).</p><p>Habitat. Recorded on rocky shores and aquaculture ropes.</p><p>Material examined. Site 1, Sriracha; Site 6, mouth of Kungkraben Bay; Site 7, south Kungkraben Bay; Site 9, Pattaya. Magallana bilineata was also identified from the aquaculture farms in Chonburi.</p><p>Published Gulf of Thailand records. Crassostrea bilineata (Röding, 1798): Nabhitabhata (2009); Bussarawit &amp; Cedhagen (2010, 2012). Crassostrea lugubris (Sowerby II, 1871): Aungtonya et al. (1999); Murugan et al. (1999);</p><p>Day et al. (2000); Trivej &amp; Kesjinda (2018). Crassostrea iredalei Faustino, 1932: Aungtonya et al. (1999); Yoosukh &amp; Duangdee (1999); Klinbunga et al. (2000, 2001, 2002, 2003, 2005); Yoosukh (2000); Lam &amp; Morton (2004); Bussarawit et al. (2006); Bussarawit &amp; Simonsen (2006a).</p><p>Geographic range. Native to Southeast Asia, with sequenced records from: India, Thailand, Malaysia, Singapore, southern Japan, and Vietnam. Unsequenced records are from Pakistan and the Philippines (Tan et al., 2024). Introduced to Queensland, Australia (Willan et al., 2021).</p><p>Remarks. Magallana bilineata is known as the black scar oyster because its black adductor muscle scar differentiates it from M. belcheri, the white scar oyster, with its white adductor muscle scar. Magallana bilineata is well known in Thailand where it has been variously identified as Crassostrea bilineata, C. lugubris, and C. iredalei . Torigoe and Bussarawit (2010) clarified that there is a single species present in Thailand ( C. bilineata), and C. lugubris and C. iredalei are synonyms. Identified in the field as Crassostrea sp. (Table 2). The species was introduced to aquaculture farms in the Sriracha area about 20 years ago from Kungkraben Bay and has now become naturalised in the region (Attawut Kuntavong, pers. comm.).</p></div>	https://treatment.plazi.org/id/038E878C7B43FFA3DFA5FA8FFBD3FC08	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B43FFA3DC18FC42FB01F808.text	038E878C7B43FFA3DC18FC42FB01F808.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Magallana Salvi & Mariottini 2016	<div><p>Published Magallana records in the Gulf of Thailand rejected. Saccostrea dactylena (Iredale, 1939) was reported by van Gemert (2003) from Ko Samui in the southern Gulf of Thailand. Saxostrea commercialis dactylena Iredale, 1939 was described as an ecomorph from a specimen collected at Lindeman Island, Great Barrier Reef, Queensland. The species is accepted as valid by WoRMS (MolluscaBase eds., 2024) and is included in the genus Magallana . Van Gemert (2003) simply lists S. dactylena without a description or photograph. As there are no validated records from the Gulf of Thailand, the record is rejected.</p><p>Magallana gigas (Thunberg, 1793) was reported as Crassostrea gigas (Thunberg, 1793) by Aungtonya et al. (1999), Swennen et al. (2001), Robba et al. (2002), Printrakoon et al. (2008), and Sanpanich (2011). This is the Pacific oyster that has been widely introduced for aquaculture (Botta et al., 2020). It has also been reported from Singapore, but Tan et al. (2024) conducted a detailed investigation of intertidal oysters in Singapore and concluded the Singapore records of M. gigas were based on outdated taxonomy and the species is not present in Singapore. Similarly, the DNA sequences obtained for Magallana for the present paper were all M. belcheri and M. bilineata; M. gigas was not recorded.</p><p>Magallana rivularis (Gould, 1861) was reported as Ostrea rivularis Gould, 1861 by Lynge (1909). This species is considered a taxon inquirendum by WoRMS (MolluscaBase eds., 2024). Photographs of the Lynge specimens were obtained from the Natural History Museum of Denmark but were unidentifiable fragments.</p></div>	https://treatment.plazi.org/id/038E878C7B43FFA3DC18FC42FB01F808	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B40FFA1DFFBF8CCFA34F7C2.text	038E878C7B40FFA1DFFBF8CCFA34F7C2.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Saccostrea Dollfus & Dautzenberg 1920	<div><p>Genus Saccostrea Dollfus &amp; Dautzenberg, 1920</p><p>Saccostrea is a widespread genus in the Indo-Pacific, with a number of species described largely on the basis of shell morphology, but Saccostrea taxonomy remains very confusing. Lam &amp; Morton (2006) used genetic techniques in an attempt to differentiate the species. They proposed a ‘superspecies’ of S. cuccullata and a separate clade based on S. mordax (Gould, 1850) (= S. scyphophilla; see Snow et al., 2023) to include all the different ecotypes and/or forms. Recent studies indicate that 10 distinct lineages are present within Saccostrea (non- mordax); these are all probably valid species. Sekino &amp; Yamashita (2016) argued that they should not be included in S. cuccullata, but referred to them as Saccostrea A–J. This terminology was used by Snow et al. (2023) and we have followed their recommendations. Tan et al. (in press) have recently demonstrated that S. cuccullata was described from Ascension Island in the South Atlantic Ocean and does not occur in the Indo-West Pacific.</p><p>Visootiviseth et al. (1998) pointed out the confused taxonomy of small oysters in the genus Saccostrea in Thailand and used a combination of electrophoretic and morphometric techniques to distinguish three species: A, B, and C. All three occurred in the Gulf of Thailand but were not named. Klinbunga et al. (2005) also recognised three groups (1–3) of Saccostrea in Thailand, with groups 1 and 3 occurring in the Gulf of Thailand. These results cannot be compared with the present study as Visootiviseth et al. (1998) used allozyme analysis and Klinbunga et al. (2005) used Polymerase Chain Reaction-Restriction Fragment Length Polymerase (PCR RFLP), vastly different molecular techniques from those used here.</p><p>Saccostrea species present in the upper Gulf of Thailand:</p></div>	https://treatment.plazi.org/id/038E878C7B40FFA1DFFBF8CCFA34F7C2	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B47FFA7DEDBFB1CFE6EF8E6.text	038E878C7B47FFA7DEDBFB1CFE6EF8E6.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Saccostrea Dollfus & Dautzenberg 1920	<div><p>Saccostrea F</p><p>(Figs. 5D–F, 6C, D)</p><p>Habitat. Hanging ropes, rocky shores and pier.</p><p>Material examined. Site 1, Sriracha; Site 3, Ta Kuan Beach; Site 6, mouth of Kungkraben Bay; Site 7, south Kungkraben Bay; Site 9, Pattaya; Site 10, Klongwan Pier; Site 13, Kao Ta Kiep. Identified in the field as Saccostrea cuccullata, S. forskahlii, and Striostrea sp. (Table 2). Saccostrea F was also identified from the aquaculture farms in Chonburi.</p><p>Published Gulf of Thailand records. None.</p><p>Geographic range. Taiwan and Singapore (Lam &amp; Morton, 2006), Japan (Sekino &amp; Yamashita, 2016), and Queensland (McDougall et al., 2024).</p><p>Remarks. Published Gulf of Thailand records as Saccostrea forskahlii (Bussarawit et al., 2006), specimen collected from Ang Sila Chonburi oyster farm.</p></div>	https://treatment.plazi.org/id/038E878C7B47FFA7DEDBFB1CFE6EF8E6	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B47FFA4DC32FB9CFD33FF28.text	038E878C7B47FFA4DC32FB9CFD33FF28.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Saccostrea scyphophilla (Peron & Lesueur 1807)	<div><p>Saccostrea scyphophilla (Péron &amp; Lesueur, 1807)</p><p>(Fig. 4G–I)</p><p>Habitat. Rocky shore.</p><p>Material examined. Site 2, Samaesan. Identified in the field as Saccostrea cuccullata (Table 2).</p><p>Published Gulf of Thailand records. Reported as Saccostrea mordax (Gould, 1850) by Kurozumi et al. (1989) and Yoosukh (2000).</p><p>Geographic range. Australia (Western Australia to New South Wales), Japan, China, and Taiwan (Lam &amp; Morton, 2006). Sekino &amp; Yamashita (2013) showed a S. cucullata seq (AY038076) collected from Thailand was actually S. mordax, but S. mordax is considered to be a synonym of S. scyphophilla (MolluscaBase eds., 2024).</p><p>Remarks. There are numerous literature references of S. mordax on the more open Thai coastline on the Andaman Sea, but we could only find records in the Gulf of Thailand by Kurozumi et al. (1989) and Yoosukh (2000). We detected the species only on the rocky shore at Samaesan. Saccostrea mordax was originally described from Fiji. While there are GenBank sequences available for the species, there are none from the type locality. Huber (2010) discusses the taxonomic history of the species in detail. Saccostrea scyphophilla was described by Péron &amp; Lesueur (1807) from Shark Bay, Western Australia, and Huber (2010) considers the species to be the same, with S. scyphophilla having priority. Our DNA sequences of specimens collected in Samaesan (Fig. 3) match those of Snow et al. (2023) and Wells et al. (2024), so we consider the Thai species to be S. scyphophilla .</p></div>	https://treatment.plazi.org/id/038E878C7B47FFA4DC32FB9CFD33FF28	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B47FFA7DFB1F8DCFA4EFC26.text	038E878C7B47FFA7DFB1F8DCFA4EFC26.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Saccostrea spathulata (Lamarck 1819)	<div><p>Saccostrea spathulata (Lamarck, 1819)</p><p>(Fig. 5G–I)</p><p>Habitat. Rocky shore.</p><p>Material examined. Site 2, Samaesan. Identified in the field as Ostrea sp. (Table 2).</p><p>Published Gulf of Thailand records. None.</p><p>Geographic range. Uncertain, sequenced records from Queensland, Western Australia, and Japan (McDougall et al., 2024).</p><p>Remarks. This is the species previously referred to as Saccostrea J. Sekino &amp; Yamashita (2016), McDougall et al. (2024), and Richardson et al. (2024) all presented evidence to support their conclusion Saccostrea J is actually S. spathulata .</p></div>	https://treatment.plazi.org/id/038E878C7B47FFA7DFB1F8DCFA4EFC26	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
038E878C7B44FFA4DF2AFEA2FE7FF7C8.text	038E878C7B44FFA4DF2AFEA2FE7FF7C8.taxon	http://purl.org/dc/dcmitype/Text	http://rs.tdwg.org/ontology/voc/SPMInfoItems#GeneralDescription	text/html	en	Saccostrea J. Sekino & Yamashita 2016	<div><p>Published Saccostrea records in the Gulf of Thailand rejected. There have been numerous reports of S. cuccullata (Born, 1778) in the Gulf of Thailand, but unfortunately with no DNA sequences presented, it is not clear what species were actually reported. Published Gulf of Thailand records: Ostrea cuccullata Born, 1778 reported by: Lynge, 1909. Saccostrea cuccullata (Born, 1778) reported by: Amornjaruchit (1988); Nateewathana (1995); Sanpanich (1998, 2011); Aungtonya et al. (1999); Yoosukh &amp; Duangdee (1999); Klinbunga et al. (2000, 2001, 2002, 2003, 2005); Yoosukh (2000); Swennen et al. (2001); Robba et al. (2002); van Gemert (2003); Bussarawit &amp; Simonsen (2006b); Printrakoon et al. (2008); Nabhitabhata (2009); Bussarawit &amp; Cedhagen (2010); Samakraman et al. (2010); Negri et al. (2014).</p><p>Saccostrea commercialis (Iredale &amp; Roughley, 1933) reported by Trivej &amp; Kesjinda (2018) is actually S. glomerata (Gould, 1850), but this is a misidentification.</p><p>Saccostrea forskahlii (Gmelin, 1791) . Published Gulf of Thailand records as Saccostrea forskahli: Aungtonya et al. (1999); Klinbunga et al. (2000, 2001, 2005); Bussarawit et al. (2006); Bussawarit &amp; Simonsen (2006b); Kasetsart University (2006); ONEP (2007); Nabhitabhata (2009); Bussarawit &amp; Cedhagen (2010); Sanpanich (2011). As S. forskahlii: Yoosukh &amp; Duangdee (1999). Note: Huber (2010) believes the S. forskahlii reported by Yoosukh &amp; Duangdee (1999) is actually the Melanesian S. circumsuta (Gould, 1850) . WoRMS considers S. forskahlii to be a synonym of S. cuccullata (MolluscaBase eds., 2024), but it is not clear to which lineage S. forskahlii belongs. There are only two 16S sequences submitted to GenBank under the name S. circumsuta . One matches Lam &amp; Morton (2006) lineage D and the other lineage C.</p><p>Striostrea mytiloides (Lamarck, 1819) was reported in the Gulf of Thailand by Yoosukh &amp; Duangdee (1999) and Klinbunga et al. (2000, 2001, 2005), and Striostrea (Parastriostrea) mytiloides (Lamarck, 1819) by Kurozumi et al. (1989). Huber (2010) and WoRMS (MolluscaBase eds., 2024) recorded three other species of Striostrea Vialov, 1936: S. denticulata (Born, 1778) from West Africa; S. margaritacea (Lamarck, 1819) from South Africa and the Western Indian Ocean; and S. prismatica (Gray, 1825) from the Panamic Province. Huber (2010) believed Ostrea rufa Lamarck, 1819 from the Panamic Province may be a valid Striostrea, but WoRMS classifies it as S. prismatica (MolluscaBase eds., 2024). The Japanese Ostrea circumpicta Pilsbry, 1904 was included in Striostrea by Huber (2010) but was retained in Ostrea by WoRMS (MolluscaBase eds., 2024). Regardless of the final classification of these two species, the genus Striostrea has not been recorded from the Gulf of Thailand. Ostrea mytiloides Lamarck, 1819 is accepted as Saccostrea echinata (Quoy &amp; Gaimard, 1835) by WoRMS (MolluscaBase eds., 2024), but there is no record of the DNA lineage of this species.</p></div>	https://treatment.plazi.org/id/038E878C7B44FFA4DF2AFEA2FE7FF7C8	Public Domain	No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.		Plazi	Duangdee, Teerapong;, Kitithorn Sanpanich;, Sherralee S. Lukehurst;Wells,;Fred E.	Duangdee, Teerapong, , Kitithorn Sanpanich, , Sherralee S. Lukehurst, Wells,, Fred E. (2025): Clarification of the identity of oysters in the genera Magallana and Saccostrea in the upper Gulf of Thailand based on 16 S rRNA sequences. Raffles Bulletin of Zoology 73: 12-33, DOI: 10.26107/RBZ-2025-0002
