Pholis fangi is an ecologically important fish species inhabiting Chinese coastal waters of Yellow Sea and Bohai Sea. To investigate the genetic diversity and population genetic structure of P. fangi, a fragment of 48...Pholis fangi is an ecologically important fish species inhabiting Chinese coastal waters of Yellow Sea and Bohai Sea. To investigate the genetic diversity and population genetic structure of P. fangi, a fragment of 487 bp in the first hypervariable region (HVR-1) of the mitochondrial DNA (mtDNA) control region was sequenced for 181 individuals collected from Bohai Sea and Yel- low Sea. A total of 18 polymorphic sites were detected, which defined 25 haplotypes. A moderate level of haplotype diversity (h = 0.7052) and a low level of nucleotide diversity (π= 0.0028) were detected. Both the phylogenetic tree and the haplotype network showed no significant genealogical structure difference among sampling locations. Pairwise FST comparison and hierarchical mo- lecular variance analysis (AMOVA) revealed that no significant genetic structure difference existed throughout the investigated re- gions, suggesting a high gene exchange among different populations. The results of neutrality test and mismatch distribution analysis indicated that a late Pleistocene population expansion (38000 127000 years ago) happened. Seasonal schooling migration may con- tribute to the genetically homogeneous population structure of the species.展开更多
A Syngnathus species widely distributed in Chinese seas was permanently identified as Syngnathus acus by native ichthyologists, but the taxonomic description about this species was inadequate and lacking conclusively ...A Syngnathus species widely distributed in Chinese seas was permanently identified as Syngnathus acus by native ichthyologists, but the taxonomic description about this species was inadequate and lacking conclusively molecular evidence. To identify this species, 357 individuals of this species from the coastal waters of Dandong, Yantai, Qingdao and Zhoushan were collected and measured. Morphological results showed that these slender specimens were mainly brownish, usually mottled with pale. Standard length ranged from 117 mm to 213 mm with an average length of 180.3 mm. The above characters were consistent with S. schlegeli distributed in Japan but colored differently from and much smaller than typical S. acus reported in Europe. Thus, morphological studies revealed that this species was previously misidentified as S. acus and might be S. schlegeli in reality. In addition, a fragment of cytochrome oxidase subunit I （CO1） gene of mitochondrial DNA was also sequenced for species identification, and 15 COl sequences belonging to different Syngnathus species were also used for the molecular identification. CO1 sequences of our specimens had the minimum genetic distance from recognized S. schlegeli from Japan and clustered with it firstly. The phylogenetic analysis similarly suggested that the species previously identified as S. acus in the coastal waters of China was S. schlegeli actually.展开更多
A new record ponyfish, Deveximentum megalolepis Mochizuki and Hayashi, 1989, was documented based on its morphological characteristics and DNA barcode. Fifty specimens were collected from Beibu Gulf of China and ident...A new record ponyfish, Deveximentum megalolepis Mochizuki and Hayashi, 1989, was documented based on its morphological characteristics and DNA barcode. Fifty specimens were collected from Beibu Gulf of China and identified as D. megalolepis by morphological characterization. The coloration, meristic traits, and morphometric measurements were consistent with previously published records. In general, it is a silver-white, laterally compressed and deep bodied ponyfish with 6–9 rows of scales on cheek; scale rows above lateral line 6–8; scale rows below lateral line 14–17. Mitochondrial cytochrome oxidase I subunit(COI) gene fragment was sequenced for phylogenetic analysis. There is no sequence variation of COI gene between the specimens collected in this study. The genetic distances between D. megalolepis and other congeneric species range from 3.6% to 14.0%, which were greater than the threshold for fish species delimitation. The COI sequence analysis also supported the validity of D. megalolepis at genetic level. However, the genetic distance between Chinese and Philippine individuals was about 1.2% and they formed two lineages in gene tree, which may be caused by the geographical distance.展开更多
A new Sillago species,Sillago parasihama sp.n.,is identified based on 127 specimens collected from the southern coast of China.We compared the morphological characters between Sillago parasihama and all other 11 Silla...A new Sillago species,Sillago parasihama sp.n.,is identified based on 127 specimens collected from the southern coast of China.We compared the morphological characters between Sillago parasihama and all other 11 Sillago species with two posterior extensions on the swim bladder.The new species is like S.sihama in the countable characters and color pattern,but is different from the latter by the distinct swim bladders.The swim bladder of S.parasihama is without lateral process.The posterior sub-extensions of anterolateral extensions are unique with some dendritic or sometimes stunted blind tubule,which are unilateral and outward,ex-tending along the abdominal,and are about one-third to half of the body of swim bladder in length.But the swim bladder of S.si-hama with 8-10 lateral processes,the posterior sub-extensions of anterolateral extensions are kinky,long and complicated,extend-ing along the abdominal wall below the peritoneum to the base of posterior extensions.S.parasihama can be distinguished from other species in this group by color pattern,meristic,and morphometric characters.Moreover,the results of genetic analysis using sequences of the mitochondrial cytochrome c oxidase subunit I(COI)fragment show significant interspecific-level genetic distances(0.159-0.231)between S.parasihama and 8 congeners in the group,which also support the validity of new species.We also provide a distribution map and a key of the related species.展开更多
Platycephalus in Chinese sea area has a high commercial value.However,there were mis-identifications in previous records.In this study,we fully distinguished and diagnosed all five species,Platycephalus indicus,P.cult...Platycephalus in Chinese sea area has a high commercial value.However,there were mis-identifications in previous records.In this study,we fully distinguished and diagnosed all five species,Platycephalus indicus,P.cultellatus,Platycephalus sp.,Platycephalus sp.1 and Platycephalus sp.2.The results revealed that P.cultellatus was overlooked by previous ichthyologists.Platycephalus sp.1 was misidentified as P.indicus in reality,and Platycephalus sp.2 only existed in the seas of Japan.Furthermore,morphological,especially phylogenetic analysis indicated that Platycephalus sp.from South China Sea differs from all former known species,which might be a new species.We identified all Platycephalus species in China seas for the first time,which will contribute to local species identification,biodiversity conservation and sustainable exploitation of Platycephalus species.展开更多
Sillago nigrofasciata, a small to moderate size nearshore species, is newly found along the eastern and southern coasts of China. The present study is carried out in order to analyze the population genetics of the S. ...Sillago nigrofasciata, a small to moderate size nearshore species, is newly found along the eastern and southern coasts of China. The present study is carried out in order to analyze the population genetics of the S. nigrofasciata. The control region sequence of mitochondrial DNA revealing 73 haplotypes were obtained from 162 individuals collected at 8 locations along the coast of China. The whole S. nigrofasciata population along the coast of China showed a low nucleotide diversity(0.012) and a high population diversity(haplotype diversity)(0.943), and all the 8 local populations showed low nucleotide diversities(0.014 – 0.001), suggesting the protective measures are effective. The haplotypes of the 8 local populations were widely distributed in haplotype network diagram and neighbor-joining phylogenetic tree, while no branch associating with sampling locations was detected. Recent gene flow analysis showed asymmetric gene exchanges among local populations. The pairwise FST values and unweighted pair-group method with arithmetic mean(UPGMA) tree revealed a certain amount of genetic difference among local populations. Moreover, analysis of molecular variance(AMOVA) reflected genetic differences between hypothetical subdivision groups. Neutral test and mismatch distribution of pairwise nucleotide suggested S. nigrofasciata may have experienced recent population expansion events. The historical geographic events associating with ice age may be the main explanation to the heterogeneity among local populations with short geographic distances, and the homogeneity among local populations with long geographic distances.展开更多
基金supported by the National Natural Science Foundation of China (No. 41776171)
文摘Pholis fangi is an ecologically important fish species inhabiting Chinese coastal waters of Yellow Sea and Bohai Sea. To investigate the genetic diversity and population genetic structure of P. fangi, a fragment of 487 bp in the first hypervariable region (HVR-1) of the mitochondrial DNA (mtDNA) control region was sequenced for 181 individuals collected from Bohai Sea and Yel- low Sea. A total of 18 polymorphic sites were detected, which defined 25 haplotypes. A moderate level of haplotype diversity (h = 0.7052) and a low level of nucleotide diversity (π= 0.0028) were detected. Both the phylogenetic tree and the haplotype network showed no significant genealogical structure difference among sampling locations. Pairwise FST comparison and hierarchical mo- lecular variance analysis (AMOVA) revealed that no significant genetic structure difference existed throughout the investigated re- gions, suggesting a high gene exchange among different populations. The results of neutrality test and mismatch distribution analysis indicated that a late Pleistocene population expansion (38000 127000 years ago) happened. Seasonal schooling migration may con- tribute to the genetically homogeneous population structure of the species.
基金Supported by the National Natural Science Foundation of China(No.41176117)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20120132110009)
文摘A Syngnathus species widely distributed in Chinese seas was permanently identified as Syngnathus acus by native ichthyologists, but the taxonomic description about this species was inadequate and lacking conclusively molecular evidence. To identify this species, 357 individuals of this species from the coastal waters of Dandong, Yantai, Qingdao and Zhoushan were collected and measured. Morphological results showed that these slender specimens were mainly brownish, usually mottled with pale. Standard length ranged from 117 mm to 213 mm with an average length of 180.3 mm. The above characters were consistent with S. schlegeli distributed in Japan but colored differently from and much smaller than typical S. acus reported in Europe. Thus, morphological studies revealed that this species was previously misidentified as S. acus and might be S. schlegeli in reality. In addition, a fragment of cytochrome oxidase subunit I （CO1） gene of mitochondrial DNA was also sequenced for species identification, and 15 COl sequences belonging to different Syngnathus species were also used for the molecular identification. CO1 sequences of our specimens had the minimum genetic distance from recognized S. schlegeli from Japan and clustered with it firstly. The phylogenetic analysis similarly suggested that the species previously identified as S. acus in the coastal waters of China was S. schlegeli actually.
基金supported by the Special Fund for Agroscientific Research in the Public Interest (201303048)
文摘A new record ponyfish, Deveximentum megalolepis Mochizuki and Hayashi, 1989, was documented based on its morphological characteristics and DNA barcode. Fifty specimens were collected from Beibu Gulf of China and identified as D. megalolepis by morphological characterization. The coloration, meristic traits, and morphometric measurements were consistent with previously published records. In general, it is a silver-white, laterally compressed and deep bodied ponyfish with 6–9 rows of scales on cheek; scale rows above lateral line 6–8; scale rows below lateral line 14–17. Mitochondrial cytochrome oxidase I subunit(COI) gene fragment was sequenced for phylogenetic analysis. There is no sequence variation of COI gene between the specimens collected in this study. The genetic distances between D. megalolepis and other congeneric species range from 3.6% to 14.0%, which were greater than the threshold for fish species delimitation. The COI sequence analysis also supported the validity of D. megalolepis at genetic level. However, the genetic distance between Chinese and Philippine individuals was about 1.2% and they formed two lineages in gene tree, which may be caused by the geographical distance.
基金supported by the National Key Research and Development Program of China(No.2019 YFD0901301)the National Natural Science Foundation of China(Nos.41976083,41776171).
文摘A new Sillago species,Sillago parasihama sp.n.,is identified based on 127 specimens collected from the southern coast of China.We compared the morphological characters between Sillago parasihama and all other 11 Sillago species with two posterior extensions on the swim bladder.The new species is like S.sihama in the countable characters and color pattern,but is different from the latter by the distinct swim bladders.The swim bladder of S.parasihama is without lateral process.The posterior sub-extensions of anterolateral extensions are unique with some dendritic or sometimes stunted blind tubule,which are unilateral and outward,ex-tending along the abdominal,and are about one-third to half of the body of swim bladder in length.But the swim bladder of S.si-hama with 8-10 lateral processes,the posterior sub-extensions of anterolateral extensions are kinky,long and complicated,extend-ing along the abdominal wall below the peritoneum to the base of posterior extensions.S.parasihama can be distinguished from other species in this group by color pattern,meristic,and morphometric characters.Moreover,the results of genetic analysis using sequences of the mitochondrial cytochrome c oxidase subunit I(COI)fragment show significant interspecific-level genetic distances(0.159-0.231)between S.parasihama and 8 congeners in the group,which also support the validity of new species.We also provide a distribution map and a key of the related species.
基金supported by the National Key R&D Program of China(No.2019YFD0901301)the National Natural Science Foundation of China(No.41776171)the Scientific Research Foundation of Hainan Tropical Ocean Univer-sity(No.RHDRC201907)
文摘Platycephalus in Chinese sea area has a high commercial value.However,there were mis-identifications in previous records.In this study,we fully distinguished and diagnosed all five species,Platycephalus indicus,P.cultellatus,Platycephalus sp.,Platycephalus sp.1 and Platycephalus sp.2.The results revealed that P.cultellatus was overlooked by previous ichthyologists.Platycephalus sp.1 was misidentified as P.indicus in reality,and Platycephalus sp.2 only existed in the seas of Japan.Furthermore,morphological,especially phylogenetic analysis indicated that Platycephalus sp.from South China Sea differs from all former known species,which might be a new species.We identified all Platycephalus species in China seas for the first time,which will contribute to local species identification,biodiversity conservation and sustainable exploitation of Platycephalus species.
基金supported by the National Natural Science Foundation of China (Nos.41976083 and 41776171)。
文摘Sillago nigrofasciata, a small to moderate size nearshore species, is newly found along the eastern and southern coasts of China. The present study is carried out in order to analyze the population genetics of the S. nigrofasciata. The control region sequence of mitochondrial DNA revealing 73 haplotypes were obtained from 162 individuals collected at 8 locations along the coast of China. The whole S. nigrofasciata population along the coast of China showed a low nucleotide diversity(0.012) and a high population diversity(haplotype diversity)(0.943), and all the 8 local populations showed low nucleotide diversities(0.014 – 0.001), suggesting the protective measures are effective. The haplotypes of the 8 local populations were widely distributed in haplotype network diagram and neighbor-joining phylogenetic tree, while no branch associating with sampling locations was detected. Recent gene flow analysis showed asymmetric gene exchanges among local populations. The pairwise FST values and unweighted pair-group method with arithmetic mean(UPGMA) tree revealed a certain amount of genetic difference among local populations. Moreover, analysis of molecular variance(AMOVA) reflected genetic differences between hypothetical subdivision groups. Neutral test and mismatch distribution of pairwise nucleotide suggested S. nigrofasciata may have experienced recent population expansion events. The historical geographic events associating with ice age may be the main explanation to the heterogeneity among local populations with short geographic distances, and the homogeneity among local populations with long geographic distances.
