Early Fish Resources and Their Spawning Grounds in the Raohe Section of the Wusuli River
In order to scientifically assess the early resources of fish in the Raohe reach of the Wusuli River and understand the breeding scale and spawning site position of existing fish,the early fish resources survey and environmental monitoring were carried out in the Raohe reach of the Wusuli River from June to August 2017.The results of the study show that,a total of 22 977 fish eggs were collected during the survey period,a total of 11 genera and 11 species.These include silver carp Hypophthalmichthys molitrix and Culter alburnus other important economic fish.The average density of fish eggs was 0.263 5 ind./m3.The highest density was observed on June 15th for 2.116 ind./m3.Based on the results of the survey,it is speculated that there are two silver carp spawning fields within 4 to 120 km upstream of the survey points of Wusuli River,the amount of fertilized exogenesis was about 1.2 × 108 grains.Within 20 to 90 km,the amount of fertilized egg occurrence was about 3.3 × 108.The results of Canonical Correspondence Analysis(CCA)showed that transparency and water temperature had a significant impact on the density of fish eggs.The density of fish eggs,such as Carassius auratus gibelio,Squalidus argentatus,Rostrogobio amurensis,Gobiobotia pappenheimi,and Parabotia fasciatus,was positively correlated with water temperature(p＜0.05),but negatively correlated with dissolved oxygen and transparency(p＜0.05).There is a significant positive correlation between Hemiculter bleekeri and transparency.
Wusuli Riverfish early resourcesspecies compositionenvironmental factorscanonical correspondence analysis
NETL
NSTL
万方数据
