Species composition and diversity analysis of fish in south river of Xinjin City.
Objective: The study aims order to be able to understand the current situation and effectively protect the fish resources of South River of Xinjin, and to provide some theoretical basis for ecological research of minjiang river. Method: Fish stocks and diversity index in south river in Xinjin aquatic area were investigated and analyzed in four different season from 2014 to 2015, throughout employing the local fishery man to help catch the fish under getting the permit from government. Result: According to the survey, results showed that total 34 species of fish were investigated, which were classified into 5 orders and 10 families. For the proportion of fish species, the main species were the Cyprinifomies family, the proportion up 55.8%. they were considered as the majority in South River. The second higher proportion were Siluriformes family, the total of the fish was 10 species, accounting for 29.42%. Then, a minimum of proportion was Percirmes family, the total fish was just three species, accounting for 8.82%. For the other families, Acipenseriformes and Synbranchifomies, there were just one species for each class. The results from species identification and proportion analysis showed that some economic fish were the main species in investigated river area, such as common carp, crucian carp. The results also showed that the aquatic biodiversity was relatively abundant in South River basin. The Shannon-Winener diversity index(H) was higher in summer (2.138) than in autumn (1.956). Marvellously, some introduced species were also collected in all sampled points, which might be introduced into farm pond for fish culture and escaped into the natural aquatic ecosystem because of fish farmer's negligence, such as Oxyeleotris mannorata, colored crucian carp and Trachemys scripta elegans. The difference species of fish were catch in different seasons. Moreover, the number of fish species was higher in summer than in winter. And there were significant characteristics of fish in three sample points. In Yongxing town, the species mainly was the Cyprinidae family, such as Abbottina rivularis; a large number of economic fish were collected in the last sample point, the New Nanhe Bridge, such as common carp and crucian carp. This could be explained for the establishment of fish conservation area. In addition, some release species were found in the Guanyin temple sample point, such as the color crucian. Conclusion: In conclusion, a significant protected affect was found in the river area of Establishment for fish resources protection, and in order to avoid aquatic organism escaping and bio-invasion, more attention should be pain to both fish stock introduction for aquaculture and fish release, which need to scientific management and guidance.