Genus Nassarius contains many subgenera, such as Zeuxis, Telasco, Niotha, Varicinassa, Plicarcularia, Nassarius s. str. and Reticunassa. On the basis of morphological characteristics of the shell and radula and sequen...Genus Nassarius contains many subgenera, such as Zeuxis, Telasco, Niotha, Varicinassa, Plicarcularia, Nassarius s. str. and Reticunassa. On the basis of morphological characteristics of the shell and radula and sequences of mitochondrial cytochrome oxidase subunit I (COI) and 16S rRNA genes, Nassarius specimens collected from the South China Sea were identified and phylogenetically analyzed. Although Nassarius sp. and Nassarius (Varicinassa) variciferus were morphologically different in their shells, few variations were found among their radular teeth and sequences of mtCOI and mt16S RNA genes. Therefore, Nassarius sp. should be classified as N. (Varicinassa) variciferus. Nassarius (Zeuxis) sp. has only a subtle difference from Nassarius (Zeuxis) algidus on the shell, but it shows obvious differences in radular teeth and DNA sequence, indicating that they are two distinct species. Sequence divergence of mtCOI and mt16S RNA genes within Nassarius species was much lower than that between species, suggesting that these two genes are suitable for Nassarius species identification. Phylogenetic analysis (neighbor-joining and maximum parsimony) based on mtCOI and mt16S rRNA genes revealed the presence of two groups in genus Nassarius and a closest relationship between subgenera Zeuxis and Telasco. Species of subgenus Plicarcularia did not form a single clade. The molecular phylogeny was not congruent with the previous morphological phylogeny. The subgeneric divisions of genus Nassarius appear to be uncertain and unreliable.展开更多
Nassarius causes many poisonings in China and other Asian countries.The toxicity of Nassarius is related to species and populations.However,the molecular assignment of different toxic Nassarius samples is still unclea...Nassarius causes many poisonings in China and other Asian countries.The toxicity of Nassarius is related to species and populations.However,the molecular assignment of different toxic Nassarius samples is still unclear,which deteriorates the poisoning.Our study combined toxicity,toxin detection and multiple genes DNA barcoding to assign the various toxic Nassarius species and populations from China coast.The toxicity test indicated that different Nassarius species and different populations within one Nassarius species had different toxicity.Based on High Performance Liquid Chromatography,the toxin was confirmed to be TTX.The toxin content varied in different samples.The COI,16 S and ITS sequences revealed different toxic Nassarius species as monophyletic clades.All the samples tested have been assigned to species level.However,the different toxic populations within N.succinctus,N.variciferus and N.semiplicata did not form separated clades,and the toxic and nontoxic species did not form two clades separately.Our study constructed the relationship between toxicity and taxonomy assignment of different toxic Nassarius samples based on toxicity detection and multiple gene DNA barcoding,which provides the basis for controlling poisoning and studying the toxin-resistance difference in Mollusca.It is also indicated that the toxicity of Nassarius is really related with species at the genetic level,but not absolutely related with populations.展开更多
Two species of Nassarius Duméril, 1805 from the South China Sea are described and illustrated. The specimens are in the Nassariidae collection of the Marine Biological Museum of Chinese Academy of Sciences, Qingd...Two species of Nassarius Duméril, 1805 from the South China Sea are described and illustrated. The specimens are in the Nassariidae collection of the Marine Biological Museum of Chinese Academy of Sciences, Qingdao.Nassarius concavus sp. nov., from the sandy bottom at a depth of 180 m, resembles Nassarius glabrus Zhang and Zhang, 2014 in general shell morphology, but differs from the latter in having a smaller, more slender adult shell without axial ribs on the upper teleoconch whorls. Nassarius nanshaensis sp. nov., from the Nansha Islands at a depth of 56–147 m, is similar to Nassarius maxiutongi Zhang, Zhang and Li, 2019 in the shell sculpture, but differs in having a more slender shell with a higher spire, and fewer cusps on the rachidian tooth(9–11 vs. 13–17).展开更多
基金Supported by the Youth Science Foundation of the State Oceanic Administration (No. 2009106)the Directorate Foundation of South China Sea Branch, the State Oceanic Administration (No. 0815)
文摘Genus Nassarius contains many subgenera, such as Zeuxis, Telasco, Niotha, Varicinassa, Plicarcularia, Nassarius s. str. and Reticunassa. On the basis of morphological characteristics of the shell and radula and sequences of mitochondrial cytochrome oxidase subunit I (COI) and 16S rRNA genes, Nassarius specimens collected from the South China Sea were identified and phylogenetically analyzed. Although Nassarius sp. and Nassarius (Varicinassa) variciferus were morphologically different in their shells, few variations were found among their radular teeth and sequences of mtCOI and mt16S RNA genes. Therefore, Nassarius sp. should be classified as N. (Varicinassa) variciferus. Nassarius (Zeuxis) sp. has only a subtle difference from Nassarius (Zeuxis) algidus on the shell, but it shows obvious differences in radular teeth and DNA sequence, indicating that they are two distinct species. Sequence divergence of mtCOI and mt16S RNA genes within Nassarius species was much lower than that between species, suggesting that these two genes are suitable for Nassarius species identification. Phylogenetic analysis (neighbor-joining and maximum parsimony) based on mtCOI and mt16S rRNA genes revealed the presence of two groups in genus Nassarius and a closest relationship between subgenera Zeuxis and Telasco. Species of subgenus Plicarcularia did not form a single clade. The molecular phylogeny was not congruent with the previous morphological phylogeny. The subgeneric divisions of genus Nassarius appear to be uncertain and unreliable.
基金the National Natural Science Foundation of China (No. 31600294)the Fundamental Research Funds for the Central University (No. KYZ201627)the Fundamental Research Funds for the Central University (No. KJQN201742)
文摘Nassarius causes many poisonings in China and other Asian countries.The toxicity of Nassarius is related to species and populations.However,the molecular assignment of different toxic Nassarius samples is still unclear,which deteriorates the poisoning.Our study combined toxicity,toxin detection and multiple genes DNA barcoding to assign the various toxic Nassarius species and populations from China coast.The toxicity test indicated that different Nassarius species and different populations within one Nassarius species had different toxicity.Based on High Performance Liquid Chromatography,the toxin was confirmed to be TTX.The toxin content varied in different samples.The COI,16 S and ITS sequences revealed different toxic Nassarius species as monophyletic clades.All the samples tested have been assigned to species level.However,the different toxic populations within N.succinctus,N.variciferus and N.semiplicata did not form separated clades,and the toxic and nontoxic species did not form two clades separately.Our study constructed the relationship between toxicity and taxonomy assignment of different toxic Nassarius samples based on toxicity detection and multiple gene DNA barcoding,which provides the basis for controlling poisoning and studying the toxin-resistance difference in Mollusca.It is also indicated that the toxicity of Nassarius is really related with species at the genetic level,but not absolutely related with populations.
基金The National Natural Science Foundation of China under contract Nos 31750002 and 41606191。
文摘Two species of Nassarius Duméril, 1805 from the South China Sea are described and illustrated. The specimens are in the Nassariidae collection of the Marine Biological Museum of Chinese Academy of Sciences, Qingdao.Nassarius concavus sp. nov., from the sandy bottom at a depth of 180 m, resembles Nassarius glabrus Zhang and Zhang, 2014 in general shell morphology, but differs from the latter in having a smaller, more slender adult shell without axial ribs on the upper teleoconch whorls. Nassarius nanshaensis sp. nov., from the Nansha Islands at a depth of 56–147 m, is similar to Nassarius maxiutongi Zhang, Zhang and Li, 2019 in the shell sculpture, but differs in having a more slender shell with a higher spire, and fewer cusps on the rachidian tooth(9–11 vs. 13–17).