Studies On Feed Selection And Related Nutrition Physiology In Acrossoeheilus Fasciatus During Seeding Stage

Under the condition of deteriorating ecological environment, the stream fish is often considered as one of the important indicators using for evaluating local ecological conditions. However, the stream fish ecosystem and diversity have been severely influenced by the rapid development of agriculture and industry as well as the continued growth of the population. Therefore, we should pay more attention to the stream fish diversity.The Acrossoeheilus fasciatus, as a kind of stream fish, inhabit in the stream of mountain. In recent years, the wild population of Acrossoeheilus fasciatus in field environment have been sharply declining resulted from the environmental pollution, battery over-fishing, dredging projects and other factors. In order to prevent the extinction of wild Acrossoeheilus fasciatus, we should carry out the artificial breeding. The appropriate feed is the key factor to carry out artificial breeding. Larval and juvenile of Acrossoeheilus fasciatus were chosen as the experimental subjects, and the nutritional requirements, larval stage feeds of larvae, nutritional physiology of juvenile were studied in the article. The main results were listed as follows:1. The larval Acrossoeheilus fasciatus with initial body length of9.72±0.01mm was fed either diet, rotifers, soybean milk, yolk and mixture (rotifers:soybean milk: yolk=1:1:1) for25days with triplication to explain the effects of food items on temperature tolerance, survival, growth performance and digestive enzyme activity. The result shows that:(1) The Acrossoeheilus fasciatus laver had the best growth of terminal body length15.49±0.18mm and15.19±0.12mm, specific growth rate of21.03±1.69%/d and23.01±1.25%/d (P>0.05) when fed mixture and yolk, and difference notable both groups compared with soybean milk group larvae (P<0.05).(2) There were survival of88.28%and71.18%in the developed well larvae fed rotifers and yolk (P<0.05), and difference notable both groups compared with soybean milk and mixture group laver (P<0.05).(3) There were the maximal digestive enzyme activities of lipase and amylase in the larvae was fed yolk, and lipase activity was different with other groups (P<0.05). But amylase activity was no significant difference compared with soybean milk group. There were the maximal activities of prolease in the larvae fed the rotifers (P<0.05), but fed soybean milk and mixture larvae had the minimal activities of prolease (P>0.05).2. In order to study the influence of nutritional limitation in compensation growth and the digestive enzymes activity of the larvae stage of Acrossoeheilus fasciatus, the samples were divided into six groups in25℃, group1-4fed soya-bean milk, egg yolks, rotifer and combined feed (soya-bean milk:egg yolk:rotifer=1:1:1)5d (5d after flat swim), respectively, and then all fed microdiet until25d. Group5and group6, fed with granule feedstuff until25d after the treatment of starvation5d and10d (5d after flat swim)respectively. The results showed that,l)the survival rate, growth performance and protease activity of group1and group5are significant lower than other groups the amylase and lipase activity of group2are the highest, and significant higher than group1and5. In the aspect of compensation growth, group1and group2exist the phenomenon but group3-5. The larvae of group6had no ability to ingestion when fed with granule feedstuff.3. Six groups of adolescent fish three series each every one containing12pieces weighting0.48±0.01g were fed with six different proportioning forages including three levels of protein(30%、40%and50%) and two levels of fat (8%and12%),which is mixed with fish meal, bean flour, corn flour, wheat flour and miscella (fish oil: sunflower oil2:1). The results demonstrated that:Under the level of fat8%, PER and LER touch the bottom with protein50%. However, two indicators above were the highest of protein30%, and significant difference with protein50%. The PER of protein40%was significant differences with protein50%and30%(P<0.05). The SGRW of protein40%was the highest, and no significant difference with protein30%(P>0.05), but significant difference with protein50%(P<0.05). The mortality of P50L12was highest (36.11±15.46%), P40L8was lowest (2.77±2.77%), and there were significant differences between the groups (P<0.05). From above mentioned results, the fish fed with diet containing40%protein and8%lipid got the best growth performance and the lowest of mortality. This P/L ratio was strongly recommended in practice.In conclusion, the optimum larval stage feed of Acrossoeheilus fasciatus is rotifer, and the optimum diet should contain40%protein and8%lipid. In addition, this study also provides relative breeding and protection reference of Acrossoeheilus fasciatus.