关键词: 真鲷, 同工酶, 遗传变异, 水平淀粉凝胶电泳

AbstractThis study was conducted in Shennongjia Nature Reserve in Hubei Province , China. Twelve plots within six different habitats were investigated and the method of pitfall traps was employed to compare the influence of elevation , disturbance and habitat difference on the distribution of Carabus and Cychrus . Seven species of Carabus and two of Cychrus were recorded , of which four species , C.ohshimaianus , C. blumenthaliellus , C. yokoae , and Cy. bispinosus shennongding , dominated the trap catches and accounted for 88.2 %of the total collected specimens. Elevation and disturbance influenced species distribution. Dominant species could be trapped in an interval of over 1000 m while the other species were trapped only in an interval of about 500 m. Species were richest between 1500 to 2000 m above sealevel , and individuals were most abundant between 2000 to 2500 m. Fewer species and fewer individuals were captured between 500 to 1000 m. Severe disturbance from intensive humanand natural activity strongly limited species distributions and their abundance. The highest species number was observed in habitats with a moderate degree of disturbance , and the highest abundance was found where disturbance existed in a much lower degree. Habitats in very stable and undisturbed ecosystems did not show the highest number of species and abundance. Analysis showed significant habitat preferences for each species : C. blumenthaliellus was more abundant in meadows , C. yokoae in broad-leaved forest , and C. ohshimaianus in mixed forest . Considering genus as the unit in analysis (i. e. , Carabus and Cychrus) abundance did not show significant difference at the 0.05 level among different habitats , but Carabus showed a lower abundance in mixed forests and Cychrus was more abundant in mixed forests and in meadows. Species diversity ( H′value) was highest in shrubs near rivers and lowest in coniferous forest . Broad-leaved forest showed the highest evenness value and coniferous forest the lowest , while the highest species richness was observed in mixed forest and shrubs near rivers and the lowest in broad-leaved forest and meadows. The results indicate that elevation and disturbance determine the species distribution of Carabus and Cychrus and habitat differences st rongly modify numbers of each species. For species diversity protection , it is very important to maintain environmental heterogeneity and reduce the magnitude of disturbance from human and natural activity in Shennongjia

Key words: red seabream (Pagrus major), isozyme, genetic variation, horizontal starch gel electrophoresis