| In April 2005-July 2006, the fish species, distribution and resources were investigated in the East and West rivers in Baoxing County in Sichuan Province. The influences of hydropower development on fish diversity in these rivers were evaluated, and some potential protection tactics were suggested. According to history investigated records and this investigating results, there are 13 fish species and subspecies in the East and West rivers, which belong to 2 orders, 4 families and 7 genera, and can be divided into 2 floristic elements. Among these species, Schizothorax (Racoma) davidi, Schizothorax (Rocoma) helerochilus, Schizopygopsis malacanthus baoxingensis, Beaufortia liui, Euchiloglanis davidi, Pareuchiloglanis sinensis and Pareuchiloglanis sichuanensis are classified as provincial protected animals in Sichuan Province; Schizothorax (Racoma) davidi is listed as critically endangered, and Euchiloglanis kishinouyei and Pareuchiloglanis sinensis are listed as endangered in China species red list. The fish species and resources decrease gradually from lower reaches to upper reaches of the rivers. The hydropower development in this area will result in serious influences on fish diversity. During construction, the influences involve in the water pollution due to constructing and living, and the over-fishing resulted from the need for fish consumption of the builders. After construction, the fish diversity will be influenced because of habitat loss and fragmentation due to forming of reservoirs and less runoff or dried ranges of the rivers. Therefore, the fish conservation should be considered during hydropower development on these rivers. Some protection tactics, enhancing fishery administration, improving habitats of fish, accelerating natural reserve construction, and listing Schizopygopsis malacanthus baoxingensis as vulnerable in China species red list, were put forward in this thesis.During the investigation, around 360 Schizopygopsis malacanthus baoxingensis were collected, and the age, growth and fecundity were studies in this species. There is a power relationship between body length and weight, and the regressed equation is W = 0.016159×L2.92316. Compared with scale, fin spine and vertebra, otolith is an appropriate material to determine age of this species. The annuli were clear and easily identified on section of otoliths. All samples are composed of 7-19 year old individuals, and most are 10-13 years old, which accounting for 68.75% in all samples. There is poor relationship between otolith radius and body length of fish, therefore, otolith is unsuitalbe for back-calculating fish growth. Thus, we didn't deduce growth functions for body length and weight. However, we calculated the average growth rates of body length and weight. The average growth rates of body length from age 7-19 in males were 0.75-2.06 cm/Y; in females were0.75-2.06 cm/Y; the average growth rates of body weight from age 7-19 in males were0.73-2.36 g/Y; in females werel.85-5.13 g/Y. The growth rates decreased with the age both in female and males. The individual fecundities range from 560-5608 eggs, average is 2481 eggs. The fecundities relative to body length are 64.56-366.54 eggs/cm, average is 154.2 eggs/cm. The fecundities relative to body weight are 16.7-100.5 eggs/g, average is 40.67 eggs/g. |
