Diversity Of Fishery Resources Of The Yuanshui River

The investigation of fishery resources and fish samples collecting were carried on in the Yuanshui River from October2009to May2012in Hunan province. Diversity of fishery resources and karyotype of several economic fish of the Yuanshui River were analyzed.A total of99species (not including introduced species) of fish were collected and identified in the visits. These99species of fish belong to8orders,19families and63genera. Cyprinidae including53species, is the most species-rich family, account for53.5%of the total specie captured. Two records of fish in Hunan province were found Hemiculter tchangi Fang and Coreoperca whiteheadi.The fish fauna is complex in the Yuanshui River. It belongs to China Plain Fauna Complex、Fauna of the South Plains Complex, Department of the South Mountain Complex、Neogene Early Fauna Complex、Department of the North Mountain Complex and Fauna of the North Plains Complex. China Plain Fauna Complex is the most in six fish Fauna Complexes. The Yuanshui River fishery can be divided into three ecological types by ecological habits:River-sea migratory. River-lake migratory and Sedentary. According to the feeding type, it can be divided into four types:Omnivore、Carnivore、Herbivore and Filter feeders. According to the perching habit, it can be divided into three types:Upper、 Lower and Demersa.There are69,66and77fish species found in Huaihua, Wuqiangxi reservoir and Changde sections of the river respectively. The uniformity of fish community distributes well. The diversity of fish community is rich, and the diversity of fish species in Changde section is richer than other two sections. From seasonal difference of fish species, generally, higher diversities occurred in spring and summer than in autumn and winter, and in Changde section than in the other two sections. The dominant populations in three sections of the river are difference, but small fish such as Carassius auratus、Hemiculter leucisculus、Pelteobagrus and Gobioninae has high proportion. The catches of Huaihua and Changde show miniaturization significantly. There is the highest similarity degree of the fish communities between Changde and Wuqiangxi reservoir sections.The change of species biodiversity and community structure function of fish in the Yuanshui River are mainly due to human-induced disturbance, including over-fishing, construction of hydraulic engineering infrastructure, wading activities, water pollution and so on. Over-fishing is the most significant threat to fish species biodiversity.The karyotype of several impordant economic fish of the Yuanshui River was analyzed by means of PHA injection in vivo prepared by flame-drying technique. The results show that the karyotype of Channa argus is:2N=48,4SM+24ST+20T, NF=52; the karyotype of Odontobutis obscurus is:2N=44,8ST+36T, NF=44; the karyotype of Siniperca kneri is:2N=48,6SM+12ST+30T, NF=54; the karyotype of Siniperca scherzeri is:2N=48,2SM+24ST+22T, NF=50; the karyotype of Pelteobagrus fulvidraco is:2N=52,20M+12SM+10sST+10T, NF=84; the karyotype of Pelteobagrus vachelli is:2N=52,18M+10SM+12ST+12T, NF=80; the karyotype of Pelteobagrus eupogon is:2N=50,18M+16SM+14ST+2T, NF=84; the karyotype of Pelteobagrus nitidus is:2N=52,24M+14SM+14ST, NF=90; the karyotype of the diploid Carassius auratus is2N=100,28M+22SM+28ST+22T, NF=150; and the karyotype formula of150basic chromosomes is3N=42M+33SM+42ST+33T, NF=225.The results of karyotype analysis of several economic fish in Yuanshui River have certain guiding significance on classification, evolution, origin and hybrid genetic breeding of fish.