| Odontobutis sinensis,with its delicate and delectable meat,has gained significant popularity in the market.However,the availability of wild resources of O.sinensis has sharply declined in recent years,due to the environmental pollution and the implementation of the"10-year fishing ban on fishing in Yangtze River."Consequently,the supply of fish products derived from wild resources is unable to meet the growing demand for this delicacy among the general public.To address this issue,the artificial culture of O.sinensis has become an imperative undertaking.Presently,one of the primary challenges encountered in promoting the artificial culture of O.sinensis is the availability of high-quality larvae in sufficient quantities.The success of larval rearing mainly relies on the technology employed in matching suitable bait.Thus,this study aims to compare the effects of various opening baits on the survival rate and growth indexes of fry,in order to identify the most appropriate opening baits.Additionally,the study examines the mouth cleavage and bait specifications of O.sinensis fry at different ages,with the intention of determining the optimal feeding commencement during fry rearing.Furthermore,the study explores the feeding requirements of O.sinensis under varying environmental conditions to ascertain the suitable breeding environment for achieving both quality and quantity in the breeding of O.sinensis.The main results were as follows:1.Using different heating methods on the hatching rate of brine shrimp,it was observed that the incubation method employing water bath heating yielded significantly higher hatching rates compared to the heating rod heating method.About the Tubifex hattai culture,the investigation revealed that an incubation pond with a water flow rate of 85 m L/s exhibited superior incubation effects.And the diameter of Tubifex hattai aggregations differed significantly from other treatment groups(P<0.05)when Tubifex hattai cultivation was conducted without a particular method.The results indicated that the water bath heating was better for brine shrimp incubation.And Tubifex hattai was better suited with a water flow rate of 85 m L/s,maintaining continuous water flow and a loose medium.2.Comparative analysis of the effects of brine worms and rotifers on the survival rate and size of O.sinensis fry,indicated that the survival rate of fry fed with brine worms was significantly higher than those fed with rotifers.Furthermore,the average size of brine worms,rotifers,and Tubifex hattai was observed to be smaller than the oral fissure of the larvae,there by making them suitable as bait for the larvae.Based on the growth pattern of the larvae,it can be inferred that the transition point occurs at around 10-15 days of age.Following the introduction of brine worms as the initial feed,O.sinensis fry continued to consume brine worms before switching to Tubifex hattai at approximately 10 days of age,resulting in improved breeding outcomes.3.By analysis of the growth rate and daily feeding rate of O.sinensis,considering various feeding methods and environmental conditions,the study aimed to determine the most suitable feeding method,bait density,water depth,and culture density for O.sinensis.The results revealed that the experimental group fed in fixed groups exhibited higher weight gain and survival rates compared to the experimental group fed in a uniform manner.Significant differences(P<0.05)were observed between the experimental groups with water depths of 10 cm and 20 cm in terms of cycle feeding.However,no significant difference was found between the experimental group with a water depth of 30 cm and the experimental groups with water depths of 10 cm and 20 cm.Hence,maintaining a water depth of 20 cm proved to be more favorable for breeding.In the bait fish density experiment,when the bait fish density was 750 ind./m~3,the cycle food intake increased significantly.And in cultural density experiment,the maxium of cycle food intake was in 200 ind./m~3.The suitable breeding conditions obtained from the research results include a water depth of 20 cm,a feed density higher than 750 ind./m~3,and a breeding density of 200ind./m~3.This can provide a reference basis for the industrial three-dimensional breeding of O.s sinensis.4.By applying the theoretical insights gained from previous experiments to practical production,a cohort of larvae was successfully reared into adults.Through diligent cultivation in accordance with the relevant feeding test parameters,these individuals not only survived the winter successfully but also exhibited mature gonads,thereby enabling the breeding of the subsequent generation. |
