Morphology,Feeding Habits And Reproductive Characteristics Of The Diptychus Maculates In The Kizil River,Xinjiang

Under the influence of global climate change,the water flow of the Kizil River has declined severely and the area covered by the river has been reduced year by year;coupled with overfishing,intensified construction of water conservancy facilities,and other anthropogenic factors,it has caused a significant decline in the population of the Diptychus maculates in its watershed,which is now classified as a second-class national protected fish.The conservation and rational exploitation of fish resources need to be based on fish biology,and there are few reports on the biology of D.maculates.Given this,it is necessary to grasp the morphological characteristics,digestive tract characteristics,reproductive characteristics and,food habits of the D.maculates.In this study,the morphology of D.maculates in the Kizil River section of Xinjiang was studied.The article used the methods of through path analysis and correlation analysis to analyze the morphology of D.maculates and explore the association between each morphological trait.The digestive tract of the D.maculates was studied by histological and morphological methods.We also investigated the reproductive biology of the D.maculates,including microscopic structure of gonad development,spawning type,reproductive season,initial sexual maturity length and body mass,to clarify the reproductive strategy of the Xinjiang D.maculates and to understand the reproductive characteristics of the Xinjiang D.maculates in cold water environment.The nutrition and feeding of the fish were analyzed using fatty acid and carbon and nitrogen isotope methods to determine the food source of the fish.Correlation coefficients corresponding to all morphological traits were significantly positively c orrelated,and body height,body thickness,body length,snout length,and tail shank height were t he main traits affecting body mass.The multivariate equation was established:Y=-18.863+0.105X₁+0.378X₃+0.503X₄+0.533X₆+0.660X₁₃.In the selection of parents for D.maculates with body mass as the main objective,body length should be the main reference,and body thickness,body height,snout length,and tail shank height should be the secondary reference.2.The digestive system of D.maculates has two parts:the digestive tract and the digestive glands,the digestive tract includes des oropharyngeal cavity,esophagus,in,testing and anus,the oropharyngeal cavity has pharyngeal teeth,the esophagus is short and thick,the intestine is curved and coiled in the body,the tissue structure of each section of the intestine is not very different,the tube walla is mucosal layer,submucosal layer,muscle,layer,and plasma membrane layer in order from inside to outside.The digestive gland was composed of twoparts:liver and pancreas,with the pancreas distributed diffusely around the mesentery and the hepatic,lobulethat s were not obvious.The results show that the morphology and histology of the digestive system of the abetted Labeo are highly adaptable to its feeding habits.3.Feeding analysis of D.maculates based on fatty acid labeling method and stable isotope technique,the results showed The fish is an omnivorous fish with a wide feeding range,mainly feeding on zooplankton,benthic animals,and aquatic plants,with a trophic level of secondary or tertiary consumers,This corresponds to the characteristics of its digestive tract.4.The gonads of D.maculates can be divided into six periods.In the wild population,there are more females than males,with the first sexually mature individuals being small,with females having a body length of（129.03±11.19）mm and a body mass of（24.36±10.68）g,and males having a body length of（85.09±9.04）mm and a body mass of（17.66±5.37）g,and the breeding season is concentrated in the period from May to June.The oocytes in the ovaries were fully synchronized with the development of eggs.