Fish species diversity and its seasonal variations in the Chaozhou section of Hanjiang River, Guangdong Province

To understand the status of fish species diversity and seasonal variation in the Chaozhou section of Hanjiang River, a survey was carried out at five sample sites using fixed gillnets and cage nets from May 2012 to April 2013. In this study, 53 fish species, belonging to 8 orders, 19 families and 48 genera, were col- lected. Results indicated that Cypriniformes and Perciformes were the dominant groups with 27 and 11 spe- cies and accounting for 50.9% and 20.8% of the total species, respectively. Compared with earlier research, there were 13 new species recorded. The dominant species were Megalobrama terminalis, Microphysogobio fukiensis, Squaliobarbus curriculus and Cirrhinus molitorella, which accounted for 65.78% of the total sam- ples. Shannon-Wiener index (H'), Pielou's evenness index (E') and Margalef richness index (D) were the highest in summer, followed by those in autumn, winter, and spring; Simpson index (D') was the highest in autumn, followed by those in summer, winter, and spring. A cluster analysis and non-metric mul- •研究报告•