A Study on Karyotypes and Ag-NORs of Odontobutis potamophila

In order to obtain cytogenetic data of Odontobutis potamophila,head-kidney cells were collected as experimental materials to prepare chromosome specimen. The karyotypes of O. potamophila and the distribution and amount of transcriptionally active nucleolar organizer regions on chromosomes were analyzed by Giemsa staining and Ag-NORs. The results showed that the number of diploid chromosomes of O. potamophila was 44; the genome of O. potamophila was composed of 44 telocentric chromosomes; the karyotype formula was 2 n = 44 t,NF = 44; Ag-NORs were found in the paracentromeric region of chromosome. The results may lay the foundation for revealing the genetic pattern and chromosomal evolution of O. potamophila and contribute to further genetic breeding of O. potamophila.

3种常见渔药对河川沙塘鳢幼鱼的急性毒性

采用静态急性毒性试验研究了3种常用水产用药物对河川沙塘鳢(Odontobutis potamophila)幼鱼24、48、72 h半数致死质量浓度ρ(LC50)(95%置信区间)以及安全质量浓度(SC)。结果表明,10%聚维酮碘对河川沙塘鳢幼鱼24、48、72 h的半数致死质量浓度ρ分别为1466、1148、997.6 mg/L,安全浓度为270.0 mg/L;40%辛硫磷对河川沙塘鳢幼鱼24、48、72 h的半数致死质量浓度ρ分别为4.030、1.207、0.409 mg/L,安全浓度为0.1085 mg/L;4.5%高效氯氰菊酯对河川沙塘鳢幼鱼24、48、72 h的半数致死质量浓度ρ分别为3.007、2.695、0.9740 mg/L,安全浓度为0.7246 mg/L。