This study explored the morphological characteristics and differences of the otoliths in three native species,Schizothorax biddulphi,S.eurystomus and S.curvifrons,in the Yarkand River of the Tarim River,Xinjiang,China...This study explored the morphological characteristics and differences of the otoliths in three native species,Schizothorax biddulphi,S.eurystomus and S.curvifrons,in the Yarkand River of the Tarim River,Xinjiang,China.A total of 93 specimens(27 S.biddulphi,39 S.eurystomus,and 27 S.curvifrons)were analyzed using six basic otolith morphological parameters(OA,R_(max),R_(min),OP,OL,OW)to derive six factors(F_(1),F_(2),F_(3),F_(4),F_(5),F_(6))and seven indices(RO,FF,CI,RE,EL,RR,AR)for morphological assessment.A discriminant analysis incorporating 77 Fourier coefficients of the otoliths revealed distinct morphological differences among the species.A significant power function relationship between otolith morphology and standard length was observed across the species,with R2 values ranging from 0.409 to 0.749.Principal component analysis(PCA)of 7 traditional otolith morphological indicators explained 81.243%of the variance,yielding an overall species discrimination rate of 81.65%.Further PCA of 77 Fourier harmonic values enhanced the discrimination accuracy,with the first 3 components accounting for 77.49%of the total variation and an improved discrimination rate of 100.00%.Cluster analysis resulted in the grouping of S.biddulphi and S.curvifrons together and revealed their association with S.eurystomus,indicating notable morphological distinctions.Both otolith shape indices and elliptical Fourier analysis have been useful in distinguishing the phenotypic units of different fish species.In this study,otolith morphology was applied for the first time to identify Schizothorax species,providing an in-depth description of species distribution and evolutionary history.This study provides a reference for the identification and systematic classification of Schizothorax species and a scientific basis for formulating effective species protection measures,for promoting the sustainable management of species and important habitats.展开更多
Sagittal otoliths morphology were compared to identify five Pampus species of the Chinese coast（Chinese pomfret Pampus chinensis, grey pomfret P. cinereus, southern lesser pomfret P. minor, plumage pomfret P.punctati...Sagittal otoliths morphology were compared to identify five Pampus species of the Chinese coast（Chinese pomfret Pampus chinensis, grey pomfret P. cinereus, southern lesser pomfret P. minor, plumage pomfret P.punctatissmus, and Pampus sp.）. Otoliths demonstrated species-specific characteristics with noticeable differences in overall shape, margin and anterior region among species. With species divergence, otoliths get thinner following further developed rostrum and anti-rostrum. Interspecies variation in otolith could associate with experienced different temperature and water column. The discriminant analysis presented a high classification accuracy of 96.6%, which confirms the inter-specific distinction of otolith shape and enable the species identification.展开更多
We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias...We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices(83.7%), elliptic Fourier coefficients(98.6%), or the combination of both methods(94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks(Liaodong Bay, LD; Bohai Bay, BH; Huanghe(Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta(50%–54%) and C. stigmatias(65.7%–75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone(70.2%) or in combination with shape indices(75.8%) than using only shape indices(65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species.展开更多
基金Supported by the National Natural Science Foundation of China(No.31360635)the Tianshan Talent Training Project of Xinjiang(No.2023 TSYCCX 0128)the Science and Technology Public Relations Planning in Key Fields of the XPCC Science and Technology Bureau(No.2022 DB 019)。
文摘This study explored the morphological characteristics and differences of the otoliths in three native species,Schizothorax biddulphi,S.eurystomus and S.curvifrons,in the Yarkand River of the Tarim River,Xinjiang,China.A total of 93 specimens(27 S.biddulphi,39 S.eurystomus,and 27 S.curvifrons)were analyzed using six basic otolith morphological parameters(OA,R_(max),R_(min),OP,OL,OW)to derive six factors(F_(1),F_(2),F_(3),F_(4),F_(5),F_(6))and seven indices(RO,FF,CI,RE,EL,RR,AR)for morphological assessment.A discriminant analysis incorporating 77 Fourier coefficients of the otoliths revealed distinct morphological differences among the species.A significant power function relationship between otolith morphology and standard length was observed across the species,with R2 values ranging from 0.409 to 0.749.Principal component analysis(PCA)of 7 traditional otolith morphological indicators explained 81.243%of the variance,yielding an overall species discrimination rate of 81.65%.Further PCA of 77 Fourier harmonic values enhanced the discrimination accuracy,with the first 3 components accounting for 77.49%of the total variation and an improved discrimination rate of 100.00%.Cluster analysis resulted in the grouping of S.biddulphi and S.curvifrons together and revealed their association with S.eurystomus,indicating notable morphological distinctions.Both otolith shape indices and elliptical Fourier analysis have been useful in distinguishing the phenotypic units of different fish species.In this study,otolith morphology was applied for the first time to identify Schizothorax species,providing an in-depth description of species distribution and evolutionary history.This study provides a reference for the identification and systematic classification of Schizothorax species and a scientific basis for formulating effective species protection measures,for promoting the sustainable management of species and important habitats.
基金The Public Science and Technology Research Funds Projects of Ocean under contract No.201305030the Specialized Research Fund for the Doctoral Program of Higher Education under contract No.20120132130001the Fundamental Research Funds for the Central Universities under contract No.201262004
文摘Sagittal otoliths morphology were compared to identify five Pampus species of the Chinese coast（Chinese pomfret Pampus chinensis, grey pomfret P. cinereus, southern lesser pomfret P. minor, plumage pomfret P.punctatissmus, and Pampus sp.）. Otoliths demonstrated species-specific characteristics with noticeable differences in overall shape, margin and anterior region among species. With species divergence, otoliths get thinner following further developed rostrum and anti-rostrum. Interspecies variation in otolith could associate with experienced different temperature and water column. The discriminant analysis presented a high classification accuracy of 96.6%, which confirms the inter-specific distinction of otolith shape and enable the species identification.
基金Supported by the National Natural Science Foundation of China(NSFC)(Nos.40976084,U1406403,41121064)
文摘We tested the use of otolith shape analysis to discriminate between species and stocks of five goby species( Ctenotrypauchen chinensis, Odontamblyopus lacepedii, Amblychaeturichthys hexanema, Chaeturichthys stigmatias, and Acanthogobius hasta) found in northern Chinese coastal waters. The five species were well differentiated with high overall classification success using shape indices(83.7%), elliptic Fourier coefficients(98.6%), or the combination of both methods(94.9%). However, shape analysis alone was only moderately successful at discriminating among the four stocks(Liaodong Bay, LD; Bohai Bay, BH; Huanghe(Yellow) River estuary HRE, and Jiaozhou Bay, JZ stocks) of A. hasta(50%–54%) and C. stigmatias(65.7%–75.8%). For these two species, shape analysis was moderately successful at discriminating the HRE or JZ stocks from other stocks, but failed to effectively identify the LD and BH stocks. A large number of otoliths were misclassified between the HRE and JZ stocks, which are geographically well separated. The classification success for stock discrimination was higher using elliptic Fourier coefficients alone(70.2%) or in combination with shape indices(75.8%) than using only shape indices(65.7%) in C. stigmatias whereas there was little difference among the three methods for A. hasta. Our results supported the common belief that otolith shape analysis is generally more effective for interspecific identification than intraspecific discrimination. Moreover, compared with shape indices analysis, Fourier analysis improves classification success during inter- and intra-species discrimination by otolith shape analysis, although this did not necessarily always occur in all fish species.
