Squaliobarbus curriculus is a eurythermic ?sh found mainly in East Asia. The natural germplasm resources of this species, an organism of potential economic aquacultural importance, have recently been threatened by ove...Squaliobarbus curriculus is a eurythermic ?sh found mainly in East Asia. The natural germplasm resources of this species, an organism of potential economic aquacultural importance, have recently been threatened by over?shing and habitat degradation. The objective of this study was to obtain functional genomic resources and candidate microsatellite markers for future genetic observation and germplasm protection of S. curriculus. Illumina paired-end sequencing generated over 22.20 million clean reads, which were assembled into 204 027 transcripts with an average length of 1 457 bp. A total of 112 570 protein-coding sequences(55.17%) were predicted, 111 934 of which had signi?cant matches in the NCBI nonredundant protein database. Overall, 60 450, 34 830, and 77 755 transcripts were assigned to Gene Ontology, Clusters of Orthologous Groups, and Eukaryotic Orthologous Groups categories, respectively.In addition, 44 781 transcripts(21.95%) were mapped to 230 KEGG pathways. A total of 51 426 candidate simple sequence repeat(SSR) markers were identi?ed and used to design 36 149 PCR primer pairs. Fifty of these primer pairs were randomly selected for PCR validation in 32 S. curriculus specimens, which resulted in 25 pairs yielding the expected products. Further analysis revealed that 40%(10) of the 25 ampli?ed loci were polymorphic. The transcriptomic pro?le and SSR repertoire obtained in this study should facilitate population genetic studies and germplasm resource protection of S. curriculus.展开更多
The toxicities of 4 common endocrine-disrupting chemicals （EDCs）, 17β-estradiol （E2）, p,p＇-dichlorodiphenyldi- chloro-ethylene （DDE）, 4-nonylphenol （NP） and tributyltin （TBT）, to sperm motility, fertilizat...The toxicities of 4 common endocrine-disrupting chemicals （EDCs）, 17β-estradiol （E2）, p,p＇-dichlorodiphenyldi- chloro-ethylene （DDE）, 4-nonylphenol （NP） and tributyltin （TBT）, to sperm motility, fertilization rate, hatching rate and embryonic development of Barbel chub （Squaliobarbus curriculus） were investigated in this study. The duration of sperm motility was signifi- cantly shortened by exposure to the EDCs at the threshold concentrations of 10ngL-1 for E2 and TBT, 1 μgL l for NP and 100 μgL-1 for DDE, respectively. The fertilization rate was substantially reduced by the EDCs at the lowest observable effect concentrations （LOECs） of 10 ngL-1 for E2 and TBT and 10μgL-1 for DDE and NP, respectively. Of the tested properties of S. curriculus, larval deformity rate was most sensitive to EDC exposure and was significantly increased by DDE at the lowest experimental level of 0.1 μgL-1. Other EDCs increased the larval deformity rate at the LOECs of 1 ngL-1 for E2, 10ngL-1 for TBT and 1μgL-1 for NP, re- spectively. Despite their decreases with the increasing EDC concentrations, the hatching rate and larval survival rate of S. curriculus were not significantly affected by the exposure to EDCs. The results indicated that all the 4 EDCs affected significantly and nega- tively the early life stages of the freshwater fish S. curriculus. Overall, E2 and TBT were more toxic than NP and DDE, while DDE might be more toxic to larval deformity rate than to other measured parameters. Thus, the 4 EDCs showed potential negative influ- ences on natural population dynamics of S. curriculus. Our findings provided valuable basic data for the ecological risk assessment of E2, DDE, NP and TBT.展开更多
Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The g...Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The growth coefficient K = 0.21 year<sup>–1</sup>, asymptomatic length L<sub>∞</sub> = 39.48 cm, and age at theoretical zero-length t<sub>0</sub> = –0.74 years were estimated. The von Bertalanffy growth function was calculated as L<sub>t</sub> = 39.48[1 – e<sup>–</sup><sup>0.21(t + 0.74)</sup>]. The growth curve for weight had an inflection at 5.86 years, corresponding to 29.61 cm in standard length and 372.29 g in weight. The natural mortality rate (M), the fishing mortality rate (F), and the total mortality rate (Z) were calculated as 0.51, 0.61, and 1.12 year<sup>–1</sup>, respectively. The exploitation ratio (E) was 0.54, which is greater than the value of 0.5 suggested by Gull (1971), indicating a probable state of overdevelopment. The annual average stock number and biomass of S. curriculus in the Lanxi section of Qiantang River were 31.86 × 10<sup>6</sup> individuals and 3656.82 t, respectively.展开更多
Ecological experiment was conducted in this paper to study the allometric growth in Squaliobarbus curriculus larvae and juveniles from Zhaoqing Reach of the Pearl River. The results showed that after first feeding, th...Ecological experiment was conducted in this paper to study the allometric growth in Squaliobarbus curriculus larvae and juveniles from Zhaoqing Reach of the Pearl River. The results showed that after first feeding, the organs associated to swimming, feeling and feeding of larvae differentiated rapidly, and exhibited allometric growth. The head length, tail length and head height exhibited positive allometric growth, while trunk length exhibited negative allometric growth before reaching the growth inflexion point 20 d after first feeding, and positive allometric growth after the inflection point. Body height exhibited positive allometric growth both before and after the growth inflexion point at 18 d after first feeding. The inflexion points of snout length, eye diameter and post-eye head length occurred 23, 19 and 16 d after first feeding. For swimming organs, the dorsal fin, pelvic fins and anal fin exhibited positive allometric growth both before and after the inflexion point at 18, 19 and 17 d after first feeding; but the tail fin exhibited positive allometric growth before the inflexion point at 14 d after first feeding, and negative allometric growth after the inflexion point. S. curriculus larvae can possess various abilities soon after first feeding to survive at early stage due to the rapid development of swimming, feeling, feeding and other organs, which has important ecological significance to adapt to the complex external environment.展开更多
基金Supported by the Jiangsu Collaborative Innovation Center of Regional Modern Agriculture and Environmental Protection,Huaiyin Normal University(Germplasm Production and Culture of S.curriculus,No.HSXT219)the Scientific Fund of Jiangsu Province(No.BY2015039-10)the Priority Academic Development Program of Jiangsu Higher Education Institutions,China
文摘Squaliobarbus curriculus is a eurythermic ?sh found mainly in East Asia. The natural germplasm resources of this species, an organism of potential economic aquacultural importance, have recently been threatened by over?shing and habitat degradation. The objective of this study was to obtain functional genomic resources and candidate microsatellite markers for future genetic observation and germplasm protection of S. curriculus. Illumina paired-end sequencing generated over 22.20 million clean reads, which were assembled into 204 027 transcripts with an average length of 1 457 bp. A total of 112 570 protein-coding sequences(55.17%) were predicted, 111 934 of which had signi?cant matches in the NCBI nonredundant protein database. Overall, 60 450, 34 830, and 77 755 transcripts were assigned to Gene Ontology, Clusters of Orthologous Groups, and Eukaryotic Orthologous Groups categories, respectively.In addition, 44 781 transcripts(21.95%) were mapped to 230 KEGG pathways. A total of 51 426 candidate simple sequence repeat(SSR) markers were identi?ed and used to design 36 149 PCR primer pairs. Fifty of these primer pairs were randomly selected for PCR validation in 32 S. curriculus specimens, which resulted in 25 pairs yielding the expected products. Further analysis revealed that 40%(10) of the 25 ampli?ed loci were polymorphic. The transcriptomic pro?le and SSR repertoire obtained in this study should facilitate population genetic studies and germplasm resource protection of S. curriculus.
基金supported by the National Science Foundation of China(No.40632009)
文摘The toxicities of 4 common endocrine-disrupting chemicals （EDCs）, 17β-estradiol （E2）, p,p＇-dichlorodiphenyldi- chloro-ethylene （DDE）, 4-nonylphenol （NP） and tributyltin （TBT）, to sperm motility, fertilization rate, hatching rate and embryonic development of Barbel chub （Squaliobarbus curriculus） were investigated in this study. The duration of sperm motility was signifi- cantly shortened by exposure to the EDCs at the threshold concentrations of 10ngL-1 for E2 and TBT, 1 μgL l for NP and 100 μgL-1 for DDE, respectively. The fertilization rate was substantially reduced by the EDCs at the lowest observable effect concentrations （LOECs） of 10 ngL-1 for E2 and TBT and 10μgL-1 for DDE and NP, respectively. Of the tested properties of S. curriculus, larval deformity rate was most sensitive to EDC exposure and was significantly increased by DDE at the lowest experimental level of 0.1 μgL-1. Other EDCs increased the larval deformity rate at the LOECs of 1 ngL-1 for E2, 10ngL-1 for TBT and 1μgL-1 for NP, re- spectively. Despite their decreases with the increasing EDC concentrations, the hatching rate and larval survival rate of S. curriculus were not significantly affected by the exposure to EDCs. The results indicated that all the 4 EDCs affected significantly and nega- tively the early life stages of the freshwater fish S. curriculus. Overall, E2 and TBT were more toxic than NP and DDE, while DDE might be more toxic to larval deformity rate than to other measured parameters. Thus, the 4 EDCs showed potential negative influ- ences on natural population dynamics of S. curriculus. Our findings provided valuable basic data for the ecological risk assessment of E2, DDE, NP and TBT.
文摘Population dynamics parameters and stock status of Squaliobarbus curriculus (Richardson, 1846) were analyzed from May to September 2021 in the Lanxi section of Qiantang River. FiSAT II software program was used. The growth coefficient K = 0.21 year<sup>–1</sup>, asymptomatic length L<sub>∞</sub> = 39.48 cm, and age at theoretical zero-length t<sub>0</sub> = –0.74 years were estimated. The von Bertalanffy growth function was calculated as L<sub>t</sub> = 39.48[1 – e<sup>–</sup><sup>0.21(t + 0.74)</sup>]. The growth curve for weight had an inflection at 5.86 years, corresponding to 29.61 cm in standard length and 372.29 g in weight. The natural mortality rate (M), the fishing mortality rate (F), and the total mortality rate (Z) were calculated as 0.51, 0.61, and 1.12 year<sup>–1</sup>, respectively. The exploitation ratio (E) was 0.54, which is greater than the value of 0.5 suggested by Gull (1971), indicating a probable state of overdevelopment. The annual average stock number and biomass of S. curriculus in the Lanxi section of Qiantang River were 31.86 × 10<sup>6</sup> individuals and 3656.82 t, respectively.
基金Supported by Special Fund for Agro-scientific Research in the Public Interest(201303048)Major Program of Natural Science Foundation of Guangxi(013GXNSFEA053003)
文摘Ecological experiment was conducted in this paper to study the allometric growth in Squaliobarbus curriculus larvae and juveniles from Zhaoqing Reach of the Pearl River. The results showed that after first feeding, the organs associated to swimming, feeling and feeding of larvae differentiated rapidly, and exhibited allometric growth. The head length, tail length and head height exhibited positive allometric growth, while trunk length exhibited negative allometric growth before reaching the growth inflexion point 20 d after first feeding, and positive allometric growth after the inflection point. Body height exhibited positive allometric growth both before and after the growth inflexion point at 18 d after first feeding. The inflexion points of snout length, eye diameter and post-eye head length occurred 23, 19 and 16 d after first feeding. For swimming organs, the dorsal fin, pelvic fins and anal fin exhibited positive allometric growth both before and after the inflexion point at 18, 19 and 17 d after first feeding; but the tail fin exhibited positive allometric growth before the inflexion point at 14 d after first feeding, and negative allometric growth after the inflexion point. S. curriculus larvae can possess various abilities soon after first feeding to survive at early stage due to the rapid development of swimming, feeling, feeding and other organs, which has important ecological significance to adapt to the complex external environment.
文摘以鳡鱼（Elopichthys bambusa）为父本,赤眼鳟（Squaliobarbus curriculus）为母本进行属间人工远缘杂交,对杂交F1胚胎发育情况进行了观察和记录,描述了各发育阶段的形态特征。鳡鱼（♂）和赤眼鳟（♀）杂交F1受精卵的平均受精率为（72.13±13.42）%,平均孵化率为（27.40±3.96）%;杂交F1的受精卵为晶莹半透明的圆球形,平均卵径为（0.978±0.028）mm,吸水膨胀后平均卵径为（3.740±0.055）mm,为非粘性半浮性卵;胚胎发育分为受精、卵裂和囊胚、原肠期、神经胚、器官形成期、孵化期6个阶段,其中包括30个主要时期,在温度为25~26℃的孵化条件下,杂交F1受精卵经23 h 40min孵出仔鱼,总积温为611.58℃.h。结果表明：鳡鱼（♂）和赤眼鳟（♀）杂交F1的受精卵可以正常发育,可正常孵出仔鱼,但其杂交亲和程度不高;杂交F1胚胎发育与母本赤眼鳟的发育差别较小,表现出较强的趋母性遗传的特征。
