Objective:To investigate the length distribution,sex ratio,length-weight relationship,age and growth of Raja radula in the Gulf of Gabes.Methods:The age and growth characteristic of the rough skate(Raja radula)inhabit...Objective:To investigate the length distribution,sex ratio,length-weight relationship,age and growth of Raja radula in the Gulf of Gabes.Methods:The age and growth characteristic of the rough skate(Raja radula)inhabiting in the Gulf of Gabes(Central Mediterranean Sea)was determined.A total of 1250 specimens were sampled.According to the marginal increment band its growth was annual.Results:The growth parameters were derived by using the von-Bertalanffy method and were separately evaluated as follows:TL∞=97.2 cm,K=0.15 y^(-1),t_(o)=0.35,and W_(∞)=5.28 kg,and TL∞=76.4 cm,K=0.22 y^(-1),to=0.16,and W∞=3.77 kg,for females and males respetively.The maximum age was 12 years for females and 10 years for males.Conclusions:Results from this research will provide a starting point to develop a management plan for the rough skate in the Gulf of Gabes.Further investigations are necessary to quantify the impact of the existing regulations on the population dynamics and recruitment patterns of this species in the region.展开更多
探讨并殖吸虫螺类宿主自然资源。发现采自福建北部的沼蜷属螺Paludomus一新种,命名为闽北沼蜷。参照《医学贝类学》和相关文献进行形态描述。正模(FJ6135)壳高18.15 mm,壳宽13.46 mm,壳口高14.05 mm,壳口宽8.04 mm。产地武夷山九曲溪。...探讨并殖吸虫螺类宿主自然资源。发现采自福建北部的沼蜷属螺Paludomus一新种,命名为闽北沼蜷。参照《医学贝类学》和相关文献进行形态描述。正模(FJ6135)壳高18.15 mm,壳宽13.46 mm,壳口高14.05 mm,壳口宽8.04 mm。产地武夷山九曲溪。螺层5层,顶层及原壳层多缺失,螺面呈绿褐色,各螺层宽度上向体螺层增长迅速,体螺层大而膨胀,其高度上约占全部高度的4/5。齿舌中央齿呈尖峰状,中部支齿大而突出。内缘齿单支而宽大,两侧缘各有3或5枚不甚突出小齿,分布不对称,排列公式:3-1-3,3-1-5(3),7,5。本新种可与黔沼蜷(P.quianensis Liu et al,1994)、带沼蜷(P.cinctus Liu et al,1994)比较鉴别。展开更多
基金Supported by the National Institute of Science and Technology of the Sea of Sfax(Tunisia).
文摘Objective:To investigate the length distribution,sex ratio,length-weight relationship,age and growth of Raja radula in the Gulf of Gabes.Methods:The age and growth characteristic of the rough skate(Raja radula)inhabiting in the Gulf of Gabes(Central Mediterranean Sea)was determined.A total of 1250 specimens were sampled.According to the marginal increment band its growth was annual.Results:The growth parameters were derived by using the von-Bertalanffy method and were separately evaluated as follows:TL∞=97.2 cm,K=0.15 y^(-1),t_(o)=0.35,and W_(∞)=5.28 kg,and TL∞=76.4 cm,K=0.22 y^(-1),to=0.16,and W∞=3.77 kg,for females and males respetively.The maximum age was 12 years for females and 10 years for males.Conclusions:Results from this research will provide a starting point to develop a management plan for the rough skate in the Gulf of Gabes.Further investigations are necessary to quantify the impact of the existing regulations on the population dynamics and recruitment patterns of this species in the region.
文摘探讨并殖吸虫螺类宿主自然资源。发现采自福建北部的沼蜷属螺Paludomus一新种,命名为闽北沼蜷。参照《医学贝类学》和相关文献进行形态描述。正模(FJ6135)壳高18.15 mm,壳宽13.46 mm,壳口高14.05 mm,壳口宽8.04 mm。产地武夷山九曲溪。螺层5层,顶层及原壳层多缺失,螺面呈绿褐色,各螺层宽度上向体螺层增长迅速,体螺层大而膨胀,其高度上约占全部高度的4/5。齿舌中央齿呈尖峰状,中部支齿大而突出。内缘齿单支而宽大,两侧缘各有3或5枚不甚突出小齿,分布不对称,排列公式:3-1-3,3-1-5(3),7,5。本新种可与黔沼蜷(P.quianensis Liu et al,1994)、带沼蜷(P.cinctus Liu et al,1994)比较鉴别。
